**************************************************************************** * * * Comments copyright (c) 1989 Markus Wandel * * * * Release date: February 3, 1989. * * * * The following is a complete disassembly of the Amiga 1.2 "exec", as * * found on a kickstart disk for an Amiga 1000. Everything is shown, * * right down to the padding introduced by the linker, and unused code * * fragments which probably made it in by accident. * * * * Thorough familiarity with the Rom Kernel Manual: Exec, with suitable * * updates to version 1.2, and the exec subdirectory of the include files, * * is assumed in all comments. Where existing documentation appears to * * be inadequate, or a particular section of code is judged to be more * * interesting than most, comments are more extensive. * * * * Absolutely no guarantee is made of the correctness of all information * * supplied below, nor of its usefulness. * * * * Note that virtually all references to "ROM" actually refer to the * * write-protected RAM which the kickstart disk loads into. The genuine * * ROMs on Amiga 500 and 2000 computers may not contain exactly the same * * code, although most of it should be similar. * * * * The completed disassembly file is not redistributable, and contains * * code which is copyrighted by Commodore-Amiga, and comments which are * * copyrighted by Markus Wandel. The source file used to make the * * disassembly is distributable under a limited set of conditions as * * outlined in the accompanying documentation. * * * * For Commodore-Amiga's copyright notice, see a few lines farther down. * * * **************************************************************************** ; This match word is used when looking for ROMs. FC0000 1111 ; The ROM can be started by jumping to its base address plus 2, ; or by mapping it at location zero and resetting. Either way, ; the machine starts running at FC00D2 (in the latter case, because ; the 68000's PC is loaded from location 4 at cold start). FC0002 jmp FC00D2 FC0008 0000 Garbage. FC000A FFFF ; The following version number doesn't appear to be used ; from within exec.library. FC000C 0021 FC000E 00B4 ; The following version number appears in the exec.library ; node, and this copy is checked to ensure it is still valid. FC0010 0021 Version. FC0012 00C0 Revision. FC0014 FFFFFFFF Garbage. ; The exec's ID string ; -------------------- FC0018 "exec 33.192 (8 Oct 1986)", CR, LF, 00, 00 FC0034 FFFFFFFF Garbage. ; Copyright notice. ; ----------------- FC0038 CR, LF, LF, "AMIGA ROM Operating System and Libraries", CR, LF FC0065 "Copyright (C) 1985, Commodore-Amiga, Inc.", CR, LF FC0090 "All Rights Reserved.", CR, LF, 00, 00 ; Library name ; ------------ FC00A8 "exec.library", 00, 00 ; The RomTag structure. ; --------------------- FC00B6 4AFC RTC_MATCHWORD (start of ROMTAG marker) FC00B8 00FC00B6 RT_MATCHTAG (pointer RTC_MATCHWORD) FC00BC 00FC323A RT_ENDSKIP (pointer to end of code) FC00C0 00 RT_FLAGS (no flags) FC00C1 21 RT_VERSION (version number) FC00C2 09 RT_TYPE (NT_LIBRARY) FC00C3 78 RT_PRI (priority = 126) FC00C4 00FC00A8 RT_NAME (pointer to name) FC00C8 00FC0018 RT_IDSTRING (pointer to ID string) FC00CC 00FC00D2 RT_INIT (execution address) FC00D0 reset ; We start running here. FC00D2 lea 040000,SP Set stack pointer to top of first 128K. FC00D8 move.l #$020000,D0 FC00DE subq.l #1,D0 Delay loop. FC00E0 bgt.s FC00DE ; If the ROM is also visible at F00000, or if there is another ; ROM there, jump there. FC00E2 lea FC0000(PC),A0 Load base address of ROM we're in. FC00E6 lea F00000,A1 Load (absolute address) F00000. FC00EC cmp.l A1,A0 Are we at F00000? FC00EE beq.s FC00FE If so, don't execute the following. FC00F0 lea FC00FE(PC),A5 This is relative, i.e. always points 12 bytes down from where we are. FC00F4 cmp.w #$1111,(A1) If "1111" not found at F00000, then FC00F8 bne.s FC00FE continue running below, else start FC00FA jmp 2(A1) running at F00002. ; Set up port A on the first CIA (8520-A). FC00FE move.b #3,BFE201 Set low two bits for output. FC0106 move.b #2,BFE001 Set boot ROM off, power light dim. ; Disable interrupts and DMA. FC010E lea DFF000,A4 Base address of custom chip area. FC0114 move.w #$7FFF,D0 FC0118 move.w D0,$9A(A4) Disable all interrupts. FC011C move.w D0,$9C(A4) Clear all pending interrupts. FC0120 move.w D0,$96(A4) Disable all DMA. ; Set a blank, dark gray display. FC0124 move.w #$0200,$0100(A4) BPLCON0 = Blank screen. FC012A move.w #0,$0110(A4) Bitplane 0 data = all zeros. FC0130 move.w #$0444,$0180(A4) Background colour = dark gray. ; Set up the Exception Vector Table. Vectors 2 through 47 ; (Bus Error through TRAP #15) are all all set to the initial ; exception handler. If any exception occurs now, the screen ; will turn yellow, the power light will flash, and the computer ; will be reset. FC0136 move.w #8,A0 Start at address 8 (vector #2). FC013A move.w #$2D,D1 Do 46 vectors. FC013E lea FC05B4(PC),A1 Address of initial exception handler. FC0142 move.l A1,(A0)+ Set one vector FC0144 dbra D1,FC0142(PC) Loop back. ; See if the system wants a guru put up after reboot. ; This works as follows: If for some reason, a guru can't be put ; up in the normal fashion, the system writes "HELP" at location ; zero, writes the alert data (number and 32-bit parameter) at ; location $000100, and resets. ; Early in the startup code (right here), this "HELP" is checked ; for. If it is present, it is removed, and the data at location ; $000100 is loaded into registers D6 and D7. If no "HELP" is ; found, register D6 is loaded with -1. This data will later be ; put at ExecBase->LastAlert, once the ExecBase structure has been ; built. The following subroutine call does all this. FC0148 bra FC30C4 Check for "HELP" at location 0. ; Check whether there is already a valid ExecBase data structure. ; This is important, since it indicates whether we need to clear and ; reconfigure memory (wiping out recoverable RAM disks and such), ; or whether we already know the memory configuration and can leave ; it untouched. ; Note that if the machine crashed in such a way that the ExecBase ; structure got clobbered, memory will be cleared. FC014C move.l 4,D0 Get pointer at location 4. FC0150 btst #0,D0 Check if it is an odd address. FC0154 bne.s FC01CE Go reconfigure memory if it is. FC0156 move.l D0,A6 Assume we are pointing to ExecBase. FC0158 add.l $26(A6),D0 Get complement of ExecBase. FC015C not.l D0 Check it. FC015E bne.s FC01CE Go reconfigure memory if it didn't match. FC0160 moveq #0,D1 FC0162 lea $22(A6),A0 Checksum the static part of the ExecBase FC0166 moveq #$18,D0 data structure. FC0168 add.w (A0)+,D1 FC016A dbra D0,FC0168(PC) FC016E not.w D1 Verify the checksum. FC0170 bne.s FC01CE Go reconfigure memory if not valid. ; If we get this far, we are reasonably confident that the ExecBase ; structure is OK, and run the cold start capture code if there ; is any. FC0172 move.l $2A(A6),D0 Get the cold start capture vector. FC0176 beq.s FC0184 Branch if it is zero. FC0178 move.l D0,A0 FC017A lea FC0184(PC),A5 Where to come back afterward. FC017E clr.l $2A(A6) Clear the cold start capture vector. FC0182 jmp (A0) Jump to the cold start capture code. ; We come here if the cold start capture vector was zero, or ; upon return from the cold-start capture code. We continue ; to verify the ExecBase structure. FC0184 bchg #1,BFE001 Flip the power light to bright. FC018C move.l FC0010(PC),D0 Check the version/revision numbers FC0190 cmp.l $14(A6),D0 stored in ExecBase against those in ROM. FC0194 bne.s FC01CE Go reconfigure memory if no match. FC0196 move.l $3E(A6),A3 Get end address of chip memory. FC019A cmp.l #$080000,A3 Greater than 512K? FC01A0 bhi.s FC01CE If so, it must be invalid. FC01A2 cmp.l #$040000,A3 Less than 256K? FC01A8 bcs.s FC01CE If so, it must be invalid. FC01AA move.l $4E(A6),A4 Get end address of $C00000 memory. FC01AE move.l A4,D0 FC01B0 beq FC0240 All OK if no $C00000 memory. FC01B4 cmp.l #$DC0000,A4 Check more than 1.5 meg (invalid). FC01BA bhi.s FC01CE Go reconfigure memory if so. FC01BC cmp.l #$C40000,A4 Check if less than 256K (invalid). FC01C2 bcs.s FC01CE Go reconfigure memory if so. FC01C4 move.l A4,D0 FC01C6 and.l #$03FFFF,D0 Check that ends on a 256K boundary. FC01CC beq.s FC0240 All OK if it does. ; If we come here, it was decided that there is no valid ExecBase ; data structure. This means we have to figure out what the memory ; configuration of the machine is. ; First, calculate ExecBase based on the assumption that the ExecBase ; structure will end up in chip RAM. This would put it at $0676, ; just far enough past the exception vector table to make room for ; the jump table. FC01CE lea $0400,A6 Calculate $0676. FC01D2 sub.w #$FD8A,A6 (don't ask me why they do it like this). ; Now go and check for memory in the $C00000 - $DC0000 area. ; This allows for a maximum of 1.75 megabytes of non-chip memory ; to be automatically configured if located at $C00000. FC01D6 lea C00000,A0 Lower bound for $C00000 memory. FC01DC lea DC0000,A1 High bound for $C00000 memory. FC01E2 lea FC01EA(PC),A5 Return address. FC01E6 bra FC061A Go check how much we have. FC01EA move.l A4,D0 Did we find any expansion memory? FC01EC beq.s FC0208 If not, skip the following. ; The machine has expansion RAM at $C00000. We put the ExecBase ; structure there to save chip memory. This puts it at $C00276. FC01EE move.l #$C00000,A6 Calculate $C00276. FC01F4 sub.w #$FD8A,A6 ; Now we clear the expansion memory to zeros. FC01F8 move.l A4,D0 Get end address of expansion memory. FC01FA lea C00000,A0 Get start address of expansion memory. FC0200 lea FC0208(PC),A5 Set return address. FC0204 bra FC0602 Go clear the memory. ; Having figured out the end address of expansion memory (in A4), ; and the value to use for ExecBase (in A6), we now check how much ; chip memory we have. Any memory in the first 2 megabytes of ; address space is considered to be chip memory. Less than 256K ; of chip memory is considered a fatal error. FC0208 lea 0,A0 Start looking at location 0. FC020C lea 200000,A1 Don't look past 2 megabytes. FC0212 lea FC021A(PC),A5 Set the return address. FC0216 bra FC0592 Go check the memory. FC021A cmp.l #$040000,A3 Do we have at least 256K of chip memory? FC0220 bcs.s FC0238 Bomb if not. ; Clear chip memory. Everything from $C0 (right after the end of ; the initial exception vector table we've set up) to the end of ; chip memory is cleared. FC0222 move.l #0,0 Clear location 0. FC022A move.l A3,D0 FC022C lea $C0,A0 Set start address to $C0 (end of vectors) FC0230 lea FC0240(PC),A5 Set return address. FC0234 bra FC0602 Go clear the chip memory. ; Since we have found less than 256K of chip memory, some of it ; must not be working. Turn the screen bright green, blink the ; power light, and reset. FC0238 move.w #$C0,D0 FC023C bra FC05B8 ; We continue here after we've figured out where the chip memory ; ends (256K or greater) and where the $C00000 memory ends ; (0 if none present). The two addresses are in A3 and A4, ; respectively. FC0240 lea DFF000,A0 Point to base of custom chip area. FC0246 move.w #$7FFF,$96(A0) Disable all DMA. FC024C move.w #$0200,$0100(A0) Set BPLCON0 for a blank screen. FC0252 move.w #0,$0110(A0) Set bitplane 0 data to zeros. FC0258 move.w #$0888,$0180(A0) Set background colour to medium gray. ; Clear most of the ExecBase structure to zeros. FC025E lea $54(A6),A0 Point at ExecBase->IntVects. FC0262 movem.l $0222(A6),D2-D4 Get KickMemPtr, KickTagPtr, KickCheckSum. FC0268 moveq #0,D0 FC026A move.w #$7D,D1 Clear all of ExecBase from IntVects FC026E move.l D0,(A0)+ to the end of the structure. FC0270 dbra D1,FC026E(PC) FC0274 movem.l D2-D4,$0222(A6) Restore Kick variables saved above. ; Set up the ExecBase pointer at location 4, and its complement ; in the ExecBase structure. FC027A move.l A6,4 Install ExecBase pointer at location 4. FC027E move.l A6,D0 FC0280 not.l D0 FC0282 move.l D0,$26(A6) Install ExecBase complement check value. ; Set up the system stack. FC0286 move.l A4,D0 Try to put stack in $C00000 RAM. FC0288 bne.s FC028C Do we have any $C00000 RAM? FC028A move.l A3,D0 If not, use chip RAM. FC028C move.l D0,SP Set system stack pointer. FC028E move.l D0,$36(A6) Store system stack upper bound. FC0292 sub.l #$001800,D0 Allow 6K bytes for system stack. FC0298 move.l D0,$3A(A6) Store system stack lower bound. ; Store the memory configuration. Next reset will use this if ; still intact, and not clear memory. FC029C move.l A3,$3E(A6) Store top of chip memory. FC02A0 move.l A4,$4E(A6) Store top of $C00000 memory. ; Part 2 of the deferred-guru procedure. Long ago, we set up ; registers D6 and D7 with the data for ExecBase->LastAlert. ; The following call writes them there. Now all is ready for ; the "alert.hook" mechanism to put up the deferred guru, if ; one was wanted. FC02A4 bsr FC30E4 Setup ExecBase->LastAlert. FC02A8 bsr FC0546 Check CPU type, and if 68881 present. FC02AC or.w D0,$0128(A6) Or the result into the Attention flags. ; Initialize the exec lists. This is driven from a data table which ; contains the offsets from ExecBase where the various lists are, ; and the list types. FC02B0 lea FC02D2(PC),A1 Point to the table. FC02B4 move.w (A1)+,D0 Get a table entry. FC02B6 beq FC033E Zero marks the end. FC02BA lea 0(A6,D0.w),A0 Add to ExecBase to get absolute address. FC02BE move.l A0,(A0) Clear the list by setting its head FC02C0 addq.l #4,(A0) pointer to point to itself, FC02C2 clr.l 4(A0) clearing its "Tail" field, FC02C6 move.l A0,8(A0) and setting up the "TailPred" pointer. FC02CA move.w (A1)+,D0 Get the list type. FC02CC move.b D0,$0C(A0) Put it into the list header. FC02D0 bra.s FC02B4 Loop back to do next list. ; Table of list header offsets and types. FC02D2 0142 000A MemList (ExecBase + $142, type = NT_MEMORY) FC02D6 0150 0008 ResourceList (ExecBase + $150, type = NT_RESOURCE) FC02DA 015E 0003 DeviceList (ExecBase + $15E, type = NT_DEVICE) FC02DE 017A 0009 LibList (ExecBase + $17A, type = NT_LIBRARY) FC02E2 0188 0004 PortList (ExecBase + $188, type = NT_MSGPORT) FC02E6 0196 0001 TaskReady (ExecBase + $196, type = NT_TASK) FC02EA 01A4 0001 TaskWait (ExecBase + $1A4, type = NT_TASK) FC02EE 016C 0002 IntrList (ExecBase + $16C, type = NT_INTERRUPT) FC02F2 01B2 000B SoftInts[0] (ExecBase + $1B2, type = NT_SOFTINT) FC02F6 01C2 000B SoftInts[1] (ExecBase + $1C2, type = NT_SOFTINT) FC02FA 01D2 000B SoftInts[2] (ExecBase + $1D2, type = NT_SOFTINT) FC02FE 01E2 000B SoftInts[3] (ExecBase + $1E2, type = NT_SOFTINT) FC0302 01F2 000B SoftInts[4] (ExecBase + $1F2, type = NT_SOFTINT) FC0306 0214 000F SemaphoreList (ExecBase + $214, type = NT_SIGNALSEM) FC030A 0000 End of table marker. ; Table used to initialize the exec's library node. FC030C 09 Type = NT_LIBRARY. FC030D 00 Priority = 0. FC030E 00FC00A8 Name = pointer to "exec.library". FC0312 06 Flags = LIBF_CHANGED | LIBF_SUMUSED. FC0313 00 Pad. FC0314 0000 NegSize (not set yet). FC0316 024C PosSize. FC0318 0021 Version. FC031A 00C0 Revision. FC031C 00FC0018 IdString = pointer to "exec ..." FC0320 00000000 Checksum (not set yet). FC0324 0001 OpenCnt = 1. ; Names to use in the system free-memory lists. FC0326 "Chip Memory", 00 FC0332 "Fast Memory", 00 FC033E lea FC2FB4(PC),A0 Get address of task crash routine. FC0342 move.l A0,$0130(A6) Install in default trap code. FC0346 move.l A0,$0134(A6) Install in default exception code. FC034A move.l #$FC1CEC,$0138(A6) Set the default task exit address. FC0352 move.l #$00FFFF,$013C(A6) Preallocate the lower 16 signals. FC035A move.w #$8000,$0140(A6) Preallocate TRAP #15 (for use in ROM-Wack breakpoints). FC0360 lea 8(A6),A1 Initialize the exec.library node FC0364 lea FC030C(PC),A0 up to and including the OpenCnt FC0368 moveq #$0C,D0 field, from the table above. FC036A move.w (A0)+,(A1)+ FC036C dbra D0,FC036A(PC) FC0370 move.l A6,A0 Make the library jump vector, using the FC0372 lea FC1A40(PC),A1 table at $FC1A40, and the MakeFunctions() FC0376 move.l A1,A2 routine. Setting A2 to the table address FC0378 bsr FC1576 signals that the table is relative. FC037C move.w D0,$10(A6) Install library negative size. FC0380 move.l A4,D0 See if we have expansion memory. FC0382 beq.s FC03A8 Branch past this if we don't. ; Add expansion memory at $C00000 to the free memory lists. FC0384 lea $024C(A6),A0 First free location = ExecBase + $024C. FC0388 lea FC0332(PC),A1 Name = "Fast Memory". FC038C moveq #0,D2 Put in memory list at priority 0. FC038E move.w #5,D1 Attributes = MEMF_FAST | MEMF_PUBLIC. FC0392 move.l A4,D0 Get end address of expansion memory. FC0394 sub.l A0,D0 Subtract address of first free location. FC0396 sub.l #$001800,D0 Subtract system stack size. FC039C bsr FC19EA Build free list and add it to system. FC03A0 lea $0400,A0 Free chip memory starts at $0400. FC03A4 moveq #0,D0 Space for stack already reserved. FC03A6 bra.s FC03B2 ; Add chip memory to free memory lists. Enter here if there is ; no expansion memory, and ExecBase therefore resides at the bottom ; of chip memory. ; Note how chip memory is added to the system list at a lower ; priority than expansion memory. This causes it to be allocated ; only when specifically requested or when expansion memory is full. FC03A8 lea $024C(A6),A0 Free chip memory is at ExecBase + $024C. FC03AC move.l #$FFFFE800,D0 Reserve 6K for system stack. ; Enter here if we do have expansion memory, with D0 and A0 set ; up as above. FC03B2 move.w #3,D1 Attributes = MEMF_CHIP | MEMF_PUBLIC. FC03B6 move.l A0,A2 FC03B8 lea FC0326(PC),A1 Name = "Chip Memory". FC03BC moveq #-$0A,D2 Priority = -10. FC03BE add.l A3,D0 Get end address of free chip memory. FC03C0 sub.l A0,D0 Subtract address of first free location. FC03C2 bsr FC19EA Build free list and add it to system. FC03C6 move.l A6,A1 Get ExecBase. FC03C8 bsr FC140C Add the exec to the system library list. ; Set the exception vector table up for actual system operation. ; Up to this point, any interrupt or exception would have caused ; the screen to turn yellow and the computer to reset. ; The format of the data table used here is explained in comments ; at the front of the data table. FC03CC lea FC0778(PC),A0 Point to data table. FC03D0 move.l A0,A1 Set up base address for the offsets. FC03D2 move.w #8,A2 Point to exception vector #2. FC03D6 bra.s FC03DE Enter the loop at the bottom. FC03D8 lea 0(A0,D0.w),A3 Convert table entry to absolute address. FC03DC move.l A3,(A2)+ Store the handler address in the EVT. FC03DE move.w (A1)+,D0 Get the next data table entry. FC03E0 bne.s FC03D8 Loop until end of table reached. FC03E2 move.w $0128(A6),D0 See if we are running on a 68010/020. FC03E6 btst #0,D0 FC03EA beq.s FC041E Skip the following if not. ; Special initialization for machines using a 68010/020. FC03EC lea FC087C(PC),A0 Point at 68010/020 bus error handler. FC03F0 move.w #8,A1 FC03F4 move.l A0,(A1)+ Fix the bus error vector. FC03F6 move.l A0,(A1)+ Fix the address error vector. FC03F8 move.l #$FC08BA,-$1C(A6) Use a different Supervisor() routine. ; Fix GetCC() for 68010/020 processors. ; We simply load the instruction sequence "MOVE.W CCR,D0 / RTS" into ; the place where the library jump vector to GetCC() normally is. FC0400 move.l #$42C04E75,-$0210(A6) ; Check if we have a 68881 numeric coprocessor, and if so, fix up ; some more vectors. This needs to be done since we also need to ; save the 68881's context when we switch tasks. FC0408 btst #4,D0 Do we have a 68881? If so, FC040C beq.s FC041E FC040E move.l #$FC108A,-$34(A6) Use a different Switch() function. FC0416 move.l #$FC10E8,-$3A(A6) Use a different Dispatch() funciton. ; Regular 68000's continue here. FC041E bsr FC125C Initialize the exec interrupt handlers. FC0422 lea DFF000,A0 Point to the custom chips. FC0428 move.w #$8200,$96(A0) Enable all DMA. FC042E move.w #$C000,$9A(A0) Enable the interrupt system. FC0434 move.w #$FFFF,$0126(A6) Set the interrupt disable level to -1. FC043A bsr FC22FA Initialize ROM-Wack. FC043E moveq #0,D1 Checksum the static part of the ExecBase FC0440 lea $22(A6),A0 data structure. FC0444 move.w #$16,D0 This is used after a reset to see if FC0448 add.w (A0)+,D1 the data structure has been clobbered. FC044A dbra D0,FC0448(PC) FC044E not.w D1 FC0450 move.w D1,$52(A6) Store the checksum. ; Now we are going to manufacture the very first task. ; We use AllocEntry() to obtain a block of memory. This is then ; used to hold the MemList from AllocEntry(), the task's stack, ; and the task descriptor. FC0454 lea FC04CC(PC),A0 Point to the MemList. FC0458 bsr FC191E AllocEntry() FC045C move.l D0,A2 Get the address of the MemList. ; It's assumed here that the allocated memory follows directly ; after the MemList. A safe assumption, since we still have ; unfragmented memory. We now create a task descriptor at the ; top of the allocated memory. The stack pointer for the task ; is initialized below the task descriptor. FC045E lea $1010(A2),A0 Point near the top of the memory block. FC0462 lea 8(A0),A1 Point to the future task descriptor. FC0466 add.l #$000010,D0 FC046C move.l D0,$3A(A1) Store stack lower bound. FC0470 move.l A0,$3E(A1) Store stack upper bound. FC0474 move.l A0,$36(A1) Set the initial stack pointer image. FC0478 move A0,USP Set the stack pointer itself. FC047A clr.b 9(A1) Priority = 0. FC047E move.b 1,8(A1) Node type = NT_TASK. FC0484 move.l #$FC00A8,$0A(A1) Task name = "exec.library". ; We initialize the task's memory list to empty, then enqueue ; the MemList holding all this memory there. This means that ; when the task dies, the memory will automatically be deallocated. FC048C lea $4A(A1),A0 Point to the task's memory list. FC0490 move.l A0,(A0) Initialize it to empty. FC0492 addq.l #4,(A0) FC0494 clr.l 4(A0) FC0498 move.l A0,8(A0) FC049C exg A1,A2 Enqueue the MemList from AllocEntry() FC049E bsr FC15D8 on the task's memory list. FC04A2 exg A1,A2 Get the task address back. ; Make this the current task, and make it ready to run. ; initialPC and finalPC are both initialized as zero, but no ; harm results, since the task can't start running yet. FC04A4 move.l A1,$0114(A6) Make this the current task. FC04A8 sub.l A2,A2 Clear A2. FC04AA move.l A2,A3 Clear A3. FC04AC bsr FC1C48 AddTask() FC04B0 move.l $0114(A6),A1 Get the pointer to the task again. FC04B4 move.b #2,$0F(A1) Make the task state TS_RUN. FC04BA bsr FC1600 Unlink it from the TaskReady queue. ; A historic moment: We turn the supervisor mode flag off. ; Starting right now, we are running as a task named "exec.library", ; and the multitasking system is operational. FC04BE and.w #0,SR Turn the supervisor bit off. FC04C2 addq.b #1,$0127(A6) Forbid() FC04C6 jsr -$8A(A6) Permit() FC04CA bra.s FC0500 ; The MemList used to allocate memory for the initial task. FC04CC 00000000 00000000 00000000 0000 A dummy list node. FC04DA 0001 1 block of memory desired. FC04DC 00010001 MEMF_PUBLIC | MEMF_CLEAR FC04E0 00001064 1124 bytes. ; Table of areas to look for RomTags in. I don't know why the ; FC0000 - 1000000 area is covered twice. The F00000 to F80000 ; area appears to be an alternate or additional place to put ROMs. FC04E4 00FC0000 01000000 FC04EC 00FC0000 01000000 FC04F4 00F00000 00F80000 FC04FC FFFFFFFF End of list marker. ; Scan for RomTags, process the KickMemPtr and KickTagPtr ; variables, and build a table of all the resident modules found. ; The address of the table of resident modules is stored in ; the ExecBase data structure. FC0500 lea FC04E4(PC),A0 Point to table of ROM address spaces. FC0504 bsr FC0900 Scan for RomTags, etc. FC0508 move.l D0,$012C(A6) Store the result in ExecBase->ResModules. FC050C bclr #1,BFE001 Set the power light to bright. ; Handle the "cool start" capture vector. Note that if we decided ; (much) earlier that ExecBase had been clobbered, it will have ; been rebuilt from scratch, and the cool start capture vector ; will be zero. Thus, we don't have to verify it further. FC0514 move.l $2E(A6),D0 Get the "cool start" capture vector. FC0518 beq.s FC051E Branch past the following if zero. FC051A move.l D0,A0 FC051C jsr (A0) Call the "cool start" capture code. ; Another historic moment. We call InitCode() to initialize the ; resident modules. This is where all the other stuff in the ROMs, ; stuff in RAM which survived the reboot, etc. comes online. We ; indicate that all those modules with the RTF_COLDSTART flag set ; should be initialized now. FC051E moveq #1,D0 RTF_COLDSTART flag must be set. FC0520 moveq #0,D1 Minimum version is 0 (any will do). FC0522 bsr FC0AF0 InitCode(). ; Yet another capture vector, this time the "WarmCapture" one. FC0526 move.l $32(A6),D0 Check the "WarmCapture" vector. FC052A beq.s FC0530 Branch past this if zero. FC052C move.l D0,A0 FC052E jsr (A0) Call the warm start capture code. ; I assume that when the DOS came online, it took over. This ; task looks like it's heading into a dead end. ; Clear all the CPU registers except for ExecBase and the stack ; pointer. FC0530 moveq #$0D,D0 Push 14 longwords of zero on FC0532 clr.l -(SP) the stack. FC0534 dbra D0,FC0532(PC) FC0538 movem.l (SP)+,D0-D7/A0-A5 Read them off again into the registers. ; This is the end of the road. Do forever FC053C jsr -$72(A6) Debug() FC0540 move.l 4,A6 Get ExecBase. FC0544 bra.s FC053C End ; Determine CPU type and whether FPP is present. ; ---------------------------------------------- ; We need to know whether a non-68000 CPU is present for two ; reasons: First, on the 68000, at least one instruction ; (MOVE.W SR,) is available in user mode, whereas on the ; newer CPU's, it is privileged. Second, on the newer CPU's, ; when an exception occurs, more information is saved on the ; stack, and in the case of a bus error, the CPU's entire state ; is dumped there so that virtual memory computers (big UNIX ; boxes for example) can recover from page faults. ; Note that the 68020 can do everything the 68010 can, and thus, ; if a 68020 is detected, both the AFB_68010 and the AFB_68020 ; flags will be set. ; We need to know whether there's an FPP present since, for task ; switches, we want to save the FPP registers on the stack as ; as the CPU registers, so each task can think it has the FPP ; all to itself. FC0546 movem.l A2/A3,-(SP) ; We are going to try 68010/020 and 68881 instructions. These will ; cause error exceptions if the respective parts aren't present, so ; we set up to trap these. FC054A move.l $10,A0 Save "Illegal Instruction" error vector. FC054E move.l $2C,A2 Save "1111 Opcode" error vector. FC0552 lea FC0582(PC),A1 Point to temporary exception handler. FC0556 move.l A1,$10 Install this address in both vectors. FC055A move.l A1,$2C FC055E move.l SP,A1 Save the stack pointer. ; Initialize the flags to zero (D0), and point to address zero (D1). ; Then we try to set the 68010 Vector Base Register, which determines ; where the exception vector table is. In the 68000, this is hard ; wired at zero. If the 68010 is present, we set it to zero. FC0560 moveq #0,D0 FC0562 moveq #0,D1 FC0564 movec D1,VBR Set Vector Base Register to 0. ; If we're still here, the CPU is at least a 68010. We thus set ; the AFB_68010 flag. Then we try to access a 68020-specific ; feature, namely, we try to enable its instruction cache. FC0568 bset #0,D0 Set AFB_68010 flag. FC056C moveq #1,D1 FC056E movec D1,CACR Try enabling the 68020 cache. ; If we're still here, we have a 68020, and so we set the AFB_68020 ; flag. Then we see if we also have a 68881 FPP, by trying to ; access one of its registers. Note that this will not cause an ; exception if no FPP is present. FC0572 bset #1,D0 Set AFB_68020 flag. FC0576 fmove.l FPCR,D1 Try reading a 68881 register. FC057A tst.l D1 Did it work? FC057C bne.s FC0582 FC057E bset #4,D0 If so, set the AFB_68881 flag. ; We continue here either from above, or, on plain Amigas, by ; an error exception from one of the foreign instructions above. ; D0 contains all the flags which have been set along the way. ; We restore the two changed entries in the EVT and the stack ; pointer, then exit. FC0582 move.l A1,SP Restore the stack pointer. FC0584 move.l A0,$10 Restore the exception vectors. FC0588 move.l A2,$2C FC058C movem.l (SP)+,A2/A3 FC0590 rts ; Chip Memory Checking Routine ; ---------------------------- ; This routine checks for the presence of memory. It is used at ; startup to determine how much chip memory is available. Note ; that it can't be used to check for memory at $C00000, and a ; special routine is provided to do this further on. ; On entry, A0 is the lower bound of the area to check, and A1 is ; the high bound. Memory is checked in 4K blocks. FC0592 moveq #0,D1 FC0594 move.l D1,(A0) Write a zero to the first location. FC0596 move.l A0,A2 Save the first location. FC0598 move.l #$F2D4B698,D0 Use this as a signature value. ; Main loop: We enter here to check each 4K block. FC059E lea $1000(A0),A0 Increment current location by 4K. FC05A2 cmp.l A0,A1 See if upper bound reached. FC05A4 bls.s FC05B0 If so, exit from the loop. FC05A6 move.l D0,(A0) Write the signature into memory. ; Longword 0 of the block being checked was initially cleared to ; zero. If it is now no longer zero, we have "wrapped around", ; i.e. due to incomplete address decoding, we have written the ; signature value at the beginning of the block. When this ; occurs, we have reached the end of memory, even though the ; signature value would read back correctly. FC05A8 tst.l (A2) Check location 0. FC05AA bne.s FC05B0 Exit if signature appears there. FC05AC cmp.l (A0),D0 See if signature can be read back. FC05AE beq.s FC059E If successful, go check more memory. ; Done, return the end address of memory to the user. Return ; via indirect jump through A5 since we don't have a stack yet. FC05B0 move.l A0,A3 FC05B2 jmp (A5) ; Error System Reset Routine ; -------------------------- ; This is the routine which blinks the power light, then resets ; the computer. It is called from the startup code if a failure ; of any sort is detected. The colour of the screen indicates ; the type of failure. ; This is the exception entry point. All vectors in the ; Exception Vector Table point here while the ROM kernel is ; initializing itself. A yellow screen means an unexpected ; exception has occurred. FC05B4 move.w #$0CC0,D0 Colour number for yellow. ; This is the non-exception entry point. From here on down it's ; a general purpose routine which can be entered with a coulour ; number in D0. FC05B8 lea DFF000,A4 Point to the custom chips. FC05BE move.w #$0200,$0100(A4) Set BPLCON0 for a blank screen. FC05C4 move.w #0,$0110(A4) Set bitplane 0 data to zeros. FC05CA move.w D0,$0180(A4) Set background colour to yellow. FC05CE moveq #$0A,D1 For D1 = 1 to 10 do FC05D0 moveq #-1,D0 Set delay to 1 time unit. FC05D2 bset #1,BFE001 Make power light dim. FC05DA dbra D0,FC05D2(PC) Delay. FC05DE lsr.w #1,D0 Set delay to 0.5 time unit. FC05E0 bclr #1,BFE001 Make power light bright. FC05E8 dbra D0,FC05E0(PC) Delay. FC05EC dbra D1,FC05D2(PC) Endfor ; Note: The "boot" and "ig" commands from ROM-Wack jump here. FC05F0 move.l #$020000,D0 Delay some more. FC05F6 subq.l #1,D0 FC05F8 bgt.s FC05F6 FC05FA reset Reset everything external to the CPU. ; Get the initial PC from the ROM (now mapped at zero due to the ; reset instruction) and start over. FC05FC move.l 4,A0 FC0600 jmp (A0) ; Memory Clear Subroutine ; ----------------------- ; This subroutine clears a block of memory. The start address is ; in A0, the end address is in D0. Since we may not have a stack, ; the return address is provided in A5. FC0602 moveq #0,D2 Value to store in memory. FC0604 sub.l A0,D0 Compute number of bytes to clear. FC0606 lsr.l #2,D0 Divide by 4 (number of longwords). FC0608 move.l D0,D1 Put the low-order 16 bits in D0, FC060A swap D1 and the high-order ones in D1, and FC060C bra.s FC0610 start at the bottom (for dbra's). FC060E move.l D2,(A0)+ Clear a longword. FC0610 dbra D0,FC060E(PC) Loop until current 256K block done. FC0614 dbra D1,FC060E(PC) Loop until everything done. FC0618 jmp (A5) Return to caller. ; $C00000 Expansion RAM Checker ; ----------------------------- ; The following routine checks for the presence of memory ; in the $C00000 - $DC0000 area. This is a nontrivial exercise, ; since if there is no memory there, we see images of the custom ; chip registers there instead, due to incomplete address decoding. ; ; This took a while to figure out, so I'm commenting it ; very heavily for my own satisfaction. ; Register A4 holds the end address of the block where we know ; RAM to reside. At first, we initialize this to the start address. ; Then, each time through the loop, we copy A4 to a temporary ; register, which we increment by 256K. FC061A move.l A0,A4 Copy start address into A4. FC061C move.l A4,A2 Copy A4 into temporary register. FC061E add.l #$040000,A2 Add 256K to temporary register. ; Now we write to an address $0F66 bytes less than the temporary ; register. If there is RAM here, this will write into it near ; the top of the 256K block. If there isn't, this will write to ; the INTENA register and disable all interrupts. FC0624 move.w #$3FFF,-$0F66(A2) Write to RAM or INTENA. ; Now we read an address $0FE4 bytes below the temporary address. ; If there is memory here, this will read it. Otherwise, it will ; read the INTENAR register. If we find a non-zero value, it must ; be memory, since all bits in INTENAR were reset above. Otherwise, ; it could be either (memory could happen to contain zero). FC062A tst.w -$0FE4(A2) Read RAM or INTENAR. FC062E bne.s FC063E If not zero, we've found memory. ; We got a zero. Make sure this isn't INTENAR by causing bits ; to be set in it. We set all of them except for the master ; interrupt enable. Again, if there's RAM here, this won't do ; anything to INTENAR, and we'll continue to see a zero. FC0630 move.w #$BFFF,-$0F66(A2) Write to RAM or INTENA. ; Read the same location as before. If this returns anything but ; $3FFF, it's fine. $3FFF means we're seeing INTENAR. If it's ; still zero, it's RAM. Anything else would be a fatal error, but ; that isn't checked for. FC0636 cmp.w #$3FFF,-$0FE4(A2) Read RAM or INTENAR. FC063C beq.s FC0644 Exit from loop if INTENAR seen. ; Now we bump up A4 by copying the temporary register back. This ; means we have found a valid 256K block. We then go on looking ; until we've reached the upper limit of the address space to check. FC063E move.l A2,A4 Update A4 (means memory was found). FC0640 cmp.l A4,A1 Compare to upper limit. FC0642 bhi.s FC061C Keep looking if not reached. ; Continue here when we've reached the end of the space to check, ; or finally seen an image of the INTENAR register. We return the ; end address of the detected RAM in A4, or zero A4 if no RAM ; was found. FC0644 move.w #$7FFF,-$0F66(A2) Disable all interrupts. FC064A cmp.l A0,A4 Was A4 ever updated? FC064C bne.s FC0650 If so, return it. FC064E sub.l A4,A4 Zero A4 (indicates no memory). FC0650 jmp (A5) Return to caller. FC0652 0000 Padding --------------------------------------------------------------------------- AddDevice( device ) A1 --------------------------------------------------------------------------- FC0654 lea $015E(A6),A0 Point to the system device list. FC0658 bsr FC1682 Add the device to the list. FC065C jsr -$01AA(A6) Update the device's vector checksum. FC0660 rts --------------------------------------------------------------------------- RemDevice( device ) A1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this. FC0662 bra FC141A Just go to RemLibrary(). --------------------------------------------------------------------------- error = OpenDevice( devName, unitNumber, ioRequest, flags ) D0 A0 D0 A1 D1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this, presumably so it can pull devices off ; disk if they aren't already in the device list. FC0666 move.l A2,-(SP) FC0668 move.l A1,A2 Point to the ioRequest. FC066A clr.b $1F(A1) Clear the io_Error field in it. FC066E movem.l D0/D1,-(SP) FC0672 move.l A0,A1 FC0674 lea $015E(A6),A0 Point to the system device list. FC0678 addq.b #1,$0127(A6) Forbid() FC067C bsr FC165A FindName() FC0680 move.l D0,A0 Get the pointer to the device. FC0682 movem.l (SP)+,D0/D1 FC0686 move.l A0,$14(A2) Store it in the ioRequest. FC068A beq.s FC06AC Return -1 if device not found. FC068C clr.l $18(A2) Clear the io_Unit pointer. FC0690 move.l A2,A1 FC0692 move.l A6,-(SP) Save ExecBase. FC0694 move.l A0,A6 Point A6 to the device's base address. FC0696 jsr -6(A6) Call the device's Open() function. FC069A move.l (SP)+,A6 Restore ExecBase. FC069C move.b $1F(A2),D0 Get the io_Error (from the Open() call). FC06A0 ext.w D0 Extend to a longword for return to FC06A2 ext.l D0 the caller. FC06A4 jsr -$8A(A6) Permit() FC06A8 move.l (SP)+,A2 FC06AA rts ; Continue here if the device was not found. FC06AC moveq #-1,D0 Set the return value to -1. FC06AE move.b D0,$1F(A2) Set the io_Error field to -1. FC06B2 bra.s FC06A4 --------------------------------------------------------------------------- CloseDevice( ioRequest ) A1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this. FC06B4 addq.b #1,$0127(A6) Forbid() FC06B8 move.l A6,-(SP) Save ExecBase. FC06BA move.l $14(A1),A6 Get the pointer to the device node. FC06BE jsr -$0C(A6) Call the device's Close() function. FC06C2 move.l (SP)+,A6 Restore ExecBase. FC06C4 jsr -$8A(A6) Permit() FC06C8 rts --------------------------------------------------------------------------- SendIO( ioRequest ) A1 --------------------------------------------------------------------------- ; The command is sent to device with the "quick I/O" bit not set. ; This means the device must always respond by sending the ; I/O request back as a reply message when done. FC06CA clr.b $1E(A1) Clear the "quick I/O" bit. FC06CE move.l A6,-(SP) Save ExecBase. FC06D0 move.l $14(A1),A6 Get pointer to device node. FC06D4 jsr -$1E(A6) Call the device's "BeginIO" entry point. FC06D8 move.l (SP)+,A6 Restore ExecBase. FC06DA rts --------------------------------------------------------------------------- error = DoIO( ioRequest ) D0 A1 --------------------------------------------------------------------------- ; The command is sent to the device with the "quick I/O" bit set. ; This allows the device to decide whether to process the request ; synchronously or asynchronously. FC06DC move.l A1,-(SP) Save ioRequest pointer for later. FC06DE move.b #1,$1E(A1) Set the "quick I/O" bit. FC06E4 move.l A6,-(SP) Save ExecBase. FC06E6 move.l $14(A1),A6 Get pointer to device node. FC06EA jsr -$1E(A6) Call the device's "BeginIO" entry point. FC06EE move.l (SP)+,A6 Restore ExecBase. FC06F0 move.l (SP)+,A1 Get ioRequest pointer back. ; Now fall through to WaitIO. --------------------------------------------------------------------------- error = WaitIO( ioRequest ) D0 A1 --------------------------------------------------------------------------- ; If the "quick I/O" bit is set, then the call to the device ; in BeginIO() finished the I/O operation synchronously, and ; we can return to the caller. Otherwise, we must wait for ; the reply message from the device. FC06F2 btst #0,$1E(A1) Check the "quick I/O" bit. FC06F8 bne.s FC0744 If still set, the I/O is complete. ; "quick I/O" bit was not (or no longer) set, so we need to ; wait for the reply message from the device. FC06FA move.l A2,-(SP) Save A2. FC06FC move.l A1,A2 Save pointer to the ioRequest. FC06FE move.l $0E(A2),A0 Get pointer to the reply port. FC0702 move.b $0F(A0),D1 Get the reply port's signal bit. FC0706 moveq #0,D0 FC0708 bset D1,D0 Convert to signal mask. FC070A move.w #$4000,DFF09A Disable() FC0712 addq.b #1,$0126(A6) FC0716 cmp.b #7,8(A2) Check if the ioRequest became NT_REPLYMSG FC071C beq.s FC0724 FC071E jsr -$013E(A6) Wait for the signal. FC0722 bra.s FC0716 Go back and check the ioRequest again. FC0724 move.l A2,A1 Unlink the ioRequest from the reply FC0726 move.l (A1),A0 port's message queue. FC0728 move.l 4(A1),A1 FC072C move.l A0,(A1) FC072E move.l A1,4(A0) FC0732 subq.b #1,$0126(A6) Enable() FC0736 bge.s FC0740 FC0738 move.w #$C000,DFF09A FC0740 move.l A2,A1 Restore pointer to the ioRequest. FC0742 move.l (SP)+,A2 Restore A2. FC0744 move.b $1F(A1),D0 Get the error field from the ioRequest. FC0748 ext.w D0 Extend to long word. FC074A ext.l D0 FC074C rts --------------------------------------------------------------------------- result = CheckIO( ioRequest ) D0 A1 --------------------------------------------------------------------------- FC074E btst #0,$1E(A1) Check the "quick I/O" bit. FC0754 beq.s FC075A If set, request is done, so... FC0756 move.l A1,D0 Return address of ioRequest. FC0758 rts FC075A cmp.b #7,8(A1) Check if ioRequest type is NT_REPLYMSG FC0760 beq.s FC0766 If so, it is finished. FC0762 moveq #0,D0 Return zero. FC0764 rts FC0766 move.l A1,D0 Return address of ioRequest. FC0768 rts --------------------------------------------------------------------------- AbortIO( ioRequest ) A1 --------------------------------------------------------------------------- FC076A move.l A6,-(SP) Save ExecBase. FC076C move.l $14(A1),A6 Get pointer to the device node. FC0770 jsr -$24(A6) Call the device's "AbortIO" entry point. FC0774 move.l (SP)+,A6 Restore ExecBase. FC0776 rts ; Table used to set up the exception vector table. ; Each entry is a 16-bit offset from the table's base address ; to the address of the exception handler for that exception. ; The final longword of zeros marks the end of the table. ; The first entry means that the handler for exception number 2 ; (bus error) is at $FC0778 + $64. The next entry is for exception ; number 3, and so on through to the end of the TRAP instruction ; vectors. FC0778 00640066 0068006A 006C006E 015A0072 FC0788 00740076 0078007A 007C007E 00800080 FC0798 00800080 00800080 00800080 008004DA FC07A8 052E0560 05B80646 068C06D2 00820084 FC07B8 00860088 008A008C 008E0090 00920094 FC07C8 00960098 009A009C 009E00A0 FC07D4 0000 End of table marker. FC07D6 0000 Padding. ; Exception entry points. The indicated entries in the Exception ; Vector Table are set to point here. ; The BSR instructions are used so that the stacked return address ; from the BSR can be used to find out which exception occurred. FC07D8 bsr.s FC0828 FC07DA bsr.s FC0828 FC07DC bsr.s FC083A Bus error. FC07DE bsr.s FC083A Address error. FC07E0 bsr.s FC0850 Illegal instruction. FC07E2 bsr.s FC0850 Divide by zero. FC07E4 bsr.s FC0850 CHK instruction. FC07E6 bsr.s FC0850 TRAPV instruction. FC07E8 bsr.s FC0850 FC07EA bsr.s FC0850 Trace mode. FC07EC bsr.s FC0850 "1010" opcode. FC07EE bsr.s FC0850 "1111" opcode. FC07F0 bsr.s FC0850 Reserved vector #12. FC07F2 bsr.s FC0850 Reserved vector #13. FC07F4 bsr.s FC0828 Reserved vector #14. FC07F6 bsr.s FC0828 Reserved vector #15. FC07F8 bra.s FC081A Reserved vectors #16-23, spurious int. FC07FA bsr.s FC0866 TRAP #0 FC07FC bsr.s FC0866 TRAP #1 FC07FE bsr.s FC0866 TRAP #2 FC0800 bsr.s FC0866 TRAP #3 FC0802 bsr.s FC0866 TRAP #4 FC0804 bsr.s FC0866 TRAP #5 FC0806 bsr.s FC0866 TRAP #6 FC0808 bsr.s FC0866 TRAP #7 FC080A bsr.s FC0866 TRAP #8 FC080C bsr.s FC0866 TRAP #9 FC080E bsr.s FC0866 TRAP #10 FC0810 bsr.s FC0866 TRAP #11 FC0812 bsr.s FC0866 TRAP #12 FC0814 bsr.s FC0866 TRAP #13 FC0816 bsr.s FC0866 TRAP #14 FC0818 bsr.s FC0866 TRAP #15 ; Handler for reserved exceptions #16-23 and spurious interrupts. ; These are dead ends (click for Guru). FC081A or.w #$0700,SR Disable all maskable interrupts. FC081E move.l #$8100000A,-(SP) Alert number (fatal). FC0824 bra FC2FB4 Freeze the task. ; Another exception handler. This one is a dead end also. FC0828 or.w #$0700,SR Disable all maskable interrupts. FC082C sub.l #$FC07DA,(SP) FC0832 lsr 2(SP) Make alert number. FC0836 bra FC2FB4 Freeze the task. ; Handler for bus and address errors (long stack frame). ; These two can be caught by the task if set up to do so. FC083A sub.l #$FC07DA,(SP) Use the return address on the stack FC0840 lsr 2(SP) to compute the exception number. FC0844 btst #5,$0C(SP) See if error occurred in supervisor mode. FC084A beq.s FC0894 If not, go to task's trap routine. FC084C bra FC2FB4 Freeze the task. ; Handler for miscellaneous other errors. ; These can be caught by the task. FC0850 sub.l #$FC07DA,(SP) Use the return address on the stack FC0856 lsr 2(SP) to compute the exception number. FC085A btst #5,4(SP) See if error occurred in supervisor mode. FC0860 beq.s FC0894 If not, go to task's trap routine. FC0862 bra FC2FB4 Guru time if in supervisor mode. ; Handler for TRAP instructions. FC0866 sub.l #$FC07BC,(SP) Use the return address on the stack FC086C lsr 2(SP) to compute the exception number. FC0870 btst #5,4(SP) See if error occurred in supervisor mode. FC0876 bne FC2FB4 Guru time if in supervisor mode. FC087A bra.s FC0894 Else go to task specific trap routine. ; Bus error handler for 68010/020 processors. These processors ; produce a more detailed stack frame when they hit a bus error ; (for use in virtual memory systems). The bus and address ; error exception vectors are set to point here at system startup ; if such a processor is being used. FC087C clr.l -(SP) Push a zero from the stack. FC087E move.w $0A(SP),2(SP) Read the exception number. FC0884 and.w #$0FFF,2(SP) Convert it to a format compatible FC088A lsr 2(SP) with the numbering scheme used FC088E lsr 2(SP) elsewhere. FC0892 bra.s FC085A Process the exception normally. ; We get here if various exceptions occurred in user mode. ; This looks up an exception handler address in the current task's ; descriptor, and jumps there. This allows each task to specify ; what is to happen if it causes an exception or executes a ; TRAP instruction. ; The task can clean up the stack and continue running if it ; wants to. All its registers are preserved. FC0894 movem.l A0/A1,-(SP) Reserve 4 words on stack and save A0. FC0898 move.l 4,A0 Get ExecBase FC089C move.l $0114(A0),A0 Get the current task pointer. FC08A0 move.l $32(A0),4(SP) Get current task's tc_TrapCode address and put it on the stack for the RTS. FC08A6 move.l (SP)+,A0 Restore A0. FC08A8 rts --------------------------------------------------------------------------- Supervisor( code_to_execute ) A5 --------------------------------------------------------------------------- ; This routine is used to run things with the CPU in supervisor ; mode. The address of the code to execute once we're in supervisor ; mode is passed in A5. ; First, we tamper with the status register (attempt to set the ; supervisor mode bit). If successful, we are already in supervisor ; mode. If not, there will be a privilege violation, handled by ; the exception handler below. FC08AA or.w #$2000,SR Tamper with the status register. ; Are we still here? If so, we are already in supervisor mode. ; Fake an exception by pushing status register and PC on the stack. FC08AE pea FC08B8 Push a fake program counter. FC08B4 move SR,-(SP) Push the status register. FC08B6 jmp (A5) Go execute the caller's code. FC08B8 rts ; The following is 68010/020 version of the above. It is used ; if the startup code has detected such a processor and pointed ; the Supervisor() vector here. FC08BA or.w #$2000,SR Tamper with the status register. FC08BE subq.l #8,SP Make room on the stack. FC08C0 move SR,(SP) Store status register. FC08C2 move.l #$FC08B8,2(SP) Store fake program counter. FC08CA move.w #$20,6(SP) Store 68010/020 stack frame type. FC08D0 jmp (A5) Go execute the caller's code. ; Privilege violation exception handler. ; First, we find out where the CPU was when it got the privilege ; violation. FC08D2 cmp.l #$FC08AA,2(SP) Was it the 68000 Supervisor() function? FC08DA beq.s FC08E6 FC08DC cmp.l #$FC08BA,2(SP) Was it the 68010/020 version? FC08E4 bne.s FC08F0 FC08E6 move.l #$FC08B8,2(SP) Yes, fix return address, and go FC08EE jmp (A5) execute the caller's code. ; If we get here, it was a real privilege violation, i.e. not one ; of the intentionally caused ones above. FC08F0 or.w #$0700,SR Disable all maskable interrupts. FC08F4 move.l #$000008,-(SP) Make alert number. FC08FA bra FC085A Freeze the current task or guru. FC08FE 0000 Padding. ; ROMTAG Scanner and "KickMemPtr/KickTagPtr" Processor ; ---------------------------------------------------- ; The routines in this section do two things. One, they scan a ; section of the CPU addressing space for resident modules, each ; flagged by a "RomTag". For an example of what a RomTag looks ; like, check out the one at the very beginning of the exec. ; The start and end addresses of each piece of CPU address space ; to look for RomTags in are given in a table, to which A0 must ; point on entry. ; A temporary list is built, containing nodes which each point to ; a RomTag. Each resident module has a name, and no two modules ; with the same name are allowed. If there is a conflict, the ; one with the higher version number or priority wins and the ; other one is discarded. ; After the list of RomTags has been compiled, we process something ; called the KickMemPtr and the KickTagPtr, found in the ExecBase ; structure. The former points to a chain of MemLists. The latter ; points to an odd type of chain containing pointers to RomTags. ; If you really need to know the format of this chain, read the ; comments at the appropriate code. ; All the MemList structures, and tables of RomTag addresses, pointed ; to by these pointers, have a checksum, also stored in ExecBase. ; If the checksum we calculate doesn't match that checksum, we ; discard all the data (assume it has been damaged in a system crash ; before the reboot). ; If the checkum matches, then we try to allocate all the pieces ; of memory pointed to by the KickMemPtr MemLists. If this is ; successful, we add all the KickTagPtr RomTags to the RomTag list. ; Presumably, the KickMemPtr list will indicate where RAM-resident ; modules are located, and if we were able to reclaim them before ; the memory got allocated for something else, we add them to the ; system again after a reboot. ; Finally, we process the RomTag list. This takes the form of ; building a table of resident module addresses, terminated with ; a zero, in memory allocated for that purpose. The RomTag list is ; deallocated. Note that the table of module addresses has the ; same format as one of the entries in the KickTagPtr list. ; Each resident module can have a flag set in its RomTag which ; which causes it to be automatically initialized later. FC0900 movem.l D3/D4/A2-A4,-(SP) ; First, create a temporary list structure to hold the found RomTags ; in. The list header is put on the stack. FC0904 link A5,#-$0E Reserve 14 bytes on the stack (enough FC0908 move.l SP,A3 for a list header), and get the address. FC090A move.l A3,(A3) Clear the list to empty. FC090C addq.l #4,(A3) FC090E clr.l 4(A3) FC0912 move.l A3,8(A3) ; Now process the table of areas to look for RomTags in. Call the ; RomTag scanning routine with the data from each table entry to ; find all the RomTags in that section of address space. FC0916 move.l A0,A2 Point to the start of the address table. FC0918 tst.l (A2) See if end of table reached. FC091A bmi.s FC0926 Negative value indicates end. FC091C move.l (A2)+,A4 Get the start address and the end address FC091E move.l (A2)+,D4 of an area to look for RomTags in. FC0920 bsr FC0948 Scan the area for RomTags. FC0924 bra.s FC0918 Loop until end of list reached. ; Now process the "Kick" variables in ExecBase. These apparently ; exist to allow a set of resident modules (such as a RRD) to ; survive a system reboot. If the checksum of all the data tables ; is still valid, we claim the memory and add the RomTags to ; the list. FC0926 bsr FC0A3C SumKickData() FC092A cmp.l $022A(A6),D0 Verify the checksum against the old one. FC092E bne.s FC093C Skip the following if not valid. FC0930 bsr FC0A94 Try to reallocate all the MemLists. FC0934 tst.l D0 Did we get all the memory back? FC0936 beq.s FC093C If not, don't bother with the KickTags. FC0938 bsr FC0A14 Process the list of "KickTags". FC093C bsr FC09DE Build a table of RomTag addresses. FC0940 unlk A5 Deallocate the RomTag list header. FC0942 movem.l (SP)+,D3/D4/A2-A4 FC0946 rts ; This routine scans an area indicated by A4 (start address) and ; D4 (end address) for RomTag structures, and puts any found RomTags ; on the RomTag list. If there is more than one version of any ; given RomTag, the newest one wins, the older ones are discarded. FC0948 movem.l D2/A5,-(SP) FC094C move.w #$4AFC,D2 Load the RomTag matchword. FC0950 move.l D4,D0 Get the end address. FC0952 sub.l A4,D0 Subtract the start address. FC0954 bls.s FC097E If less than zero, return. FC0956 lsr.l #1,D0 Divide the result by 2 (number of words). FC0958 subq.l #1,D0 Decrement by 1 (for DBcc instruction). FC095A move.l D0,D1 Split into two halves (since DBcc can FC095C swap D1 only use 16-bit counters). FC095E bra.s FC0962 FC0960 cmp.w (A4)+,D2 Look for the RomTag matchword. FC0962 dbeq D0,FC0960(PC) FC0966 dbeq D1,FC0960(PC) Loop until entire area scanned. FC096A bne.s FC097E Exit if end reached. ; We've found a RomTag matchword. A4 points to it. Check if ; this is really a RomTag by verifying the pointer directly ; after the matchword. FC096C lea -2(A4),A5 Point to the matchword. FC0970 cmp.l (A4),A5 See the longword directly after the matchword points to it. FC0972 bne.s FC0962 Not a valid RomTag if not. ; We are pointing to a valid RomTag. Add it to the RomTag list. FC0974 bsr FC0984 Add RomTag to list of found ones. ; Each RomTag has in it a pointer (RT_ENDSKIP) which points to ; the address where to start looking for the next RomTag, i.e. ; the end of whatever code/data is associated with it. FC0978 move.l 6(A5),A4 Skip to the end of the module. FC097C bra.s FC0950 Start looking for the next one. FC097E movem.l (SP)+,D2/A5 FC0982 rts ; This subroutine adds a RomTag to the list of found RomTags. ; If the current RomTag has the same name as a RomTag already in ; the list, the older (or if same age, lower priority) version ; is discarded. Memory is allocated to hold each node as needed. FC0984 move.l A3,A0 Point to the temporary list on the stack. FC0986 move.l $0E(A5),A1 Get the name of this RomTag. FC098A bsr FC165A FindName() FC098E tst.l D0 Did we find a node with this name? FC0990 beq.s FC09B8 If not, go and add the tag to the list. FC0992 move.l D0,A1 Point to the node we found. FC0994 move.l $0E(A1),A0 Compare the version numbers of the list FC0998 move.b $0B(A5),D0 node and the newly found RomTag to find FC099C cmp.b $0B(A0),D0 out which is more recent. FC09A0 blt.s FC09DC Discard current RomTag if older. FC09A2 bgt.s FC09AE Use current one if newer. FC09A4 move.b $0D(A5),D0 Version numbers match, so compare FC09A8 cmp.b $0D(A0),D0 the priority fields. FC09AC blt.s FC09DC Discard current RomTag if lower priority. ; This RomTag supersedes a previous one, which is already in the ; list. Therefore we discard the one in the list. FC09AE move.l A1,D0 Point to the node in the list. FC09B0 bsr FC1600 Unlink it from the list. FC09B4 move.l D0,A1 Keep a pointer to the node's memory. FC09B6 bra.s FC09C6 Go and make a new node out of it. ; We enter here if this RomTag doesn't supersede some other one. ; This means we have to allocate some memory for a list node to ; store information about it. FC09B8 moveq #0,D1 No particular memory requirements. FC09BA moveq #$12,D0 14 bytes. FC09BC jsr -$C6(A6) Go and allocate the memory. FC09C0 tst.l D0 Did we get the memory? FC09C2 beq.s FC09DC If not, skip the following. FC09C4 move.l D0,A1 Point to the memory. ; We have obtained 14 bytes of memory one way or another, and we ; now build a list node and add it to the list of found RomTags. FC09C6 move.b $0D(A5),9(A1) Copy the RomTag's priority. FC09CC move.l $0E(A5),$0A(A1) Copy the RomTag's name. FC09D2 move.l A5,$0E(A1) Store the RomTag's address. FC09D6 move.l A3,A0 FC09D8 bsr FC1634 And enqueue on the RomTag list. FC09DC rts ; RomTag list to resident module table converter. ; This routine scans the temporary RomTag list, and builds a table ; of resident module addresses from it. The list itself is ; deallocated. FC09DE moveq #4,D0 Start with 1 longword needed. FC09E0 move.l (A3),D4 Start at the head node of the list. FC09E2 move.l D4,A1 Get pointer to the current node. FC09E4 move.l (A1),D4 Get pointer to the next node. FC09E6 beq.s FC09EC End of list reached if zero. FC09E8 addq.l #4,D0 4 longwords needed for this node. FC09EA bra.s FC09E2 Scan the rest of the list. FC09EC move.l #$010001,D1 MEMF_PUBLIC | MEMF_CLEAR. FC09F2 jsr -$C6(A6) Allocate memory. FC09F6 move.l D0,A2 Get pointer to allocated memory. FC09F8 move.l D0,D3 Save a copy of it. FC09FA move.l (A3),D4 Start at the head of the RomTag list. FC09FC move.l D4,A1 Get pointer to current node. FC09FE move.l (A1),D4 Get pointer to next node. FC0A00 beq.s FC0A0E End of list reached if zero. FC0A02 move.l $0E(A1),(A2)+ Store pointer to this RomTag. FC0A06 moveq #$12,D0 14 bytes. FC0A08 jsr -$D2(A6) FreeMem() the list node. FC0A0C bra.s FC09FC Go process next list node. FC0A0E clr.l (A2) Mark end of "KickTag" list. FC0A10 move.l D3,D0 Return its base address. FC0A12 rts ; KickTagPtr processor. ; This routine steps through the table(s) of RomTag addresses ; pointed to by the KickTagPtr, and adds all the RomTags pointed ; to by these addresses to the list of found RomTags. FC0A14 movem.l A2/A5,-(SP) FC0A18 move.l $0226(A6),D0 Get the KickTagPtr. FC0A1C beq.s FC0A36 Just exit if it is zero. FC0A1E move.l D0,A2 Point to the first tag. FC0A20 move.l (A2)+,D0 Read a longword from the current tag. FC0A22 beq.s FC0A36 Exit if end of list reached. FC0A24 bmi.s FC0A2E If this is a link, handle it. FC0A26 move.l D0,A5 Data must be a pointer to a RomTag. FC0A28 bsr FC0984 Add the RomTag to the list. FC0A2C bra.s FC0A20 Continue with current node. FC0A2E bclr #$1F,D0 Strip high bit from pointer to next FC0A32 move.l D0,A2 node in the list of "KickTags". FC0A34 bra.s FC0A20 Go process the next node. FC0A36 movem.l (SP)+,A2/A5 FC0A3A rts --------------------------------------------------------------------------- SumKickData() --------------------------------------------------------------------------- ; This routine computes the KickCheckSum by checksumming all the ; tables associated with the KickMemPtr and KickTagPtr pointers. ; The result should is the KickCheckSum. FC0A3C movem.l D2-D4,-(SP) FC0A40 lea $0222(A6),A0 Point to the KickMemPtr in ExecBase. FC0A44 movem.l (A0),D3/D4 Get the KickMemPtr and the KickTagPtr. FC0A48 clr.l (A0)+ Clear both to zero in the ExecBase FC0A4A clr.l (A0)+ structure. FC0A4C moveq #-1,D0 Start checksum at -1. FC0A4E move.l D3,D2 Start at the old KickMemPtr. FC0A50 tst.l D2 End of list reached? FC0A52 beq.s FC0A68 Exit from loop if so. FC0A54 move.l D2,A0 Point to current MemList. FC0A56 move.l (A0),D2 Get pointer to next MemList. FC0A58 move.w $0E(A0),D1 Get the number of entries in the MemList. FC0A5C add.w D1,D1 Double it and add 4 more longwords, to FC0A5E add.w #4,D1 get the size (in longwords) of this list. FC0A62 bsr FC0A8E Checksum the MemList. FC0A66 bra.s FC0A50 Go process next MemList, if any. FC0A68 move.l D4,D2 Get the old KickTagPtr. FC0A6A beq.s FC0A80 Skip the following if none. FC0A6C move.l D2,A0 Point to the start of the list. FC0A6E bra.s FC0A72 Start checksumming the list. FC0A70 add.l D2,D0 Add a longword to the checksum. FC0A72 move.l (A0)+,D2 Get first data word at this node. FC0A74 beq.s FC0A80 Exit if end of list reached. FC0A76 bpl.s FC0A70 If high bit clear, add the data to the checksum and go on to the next longword. FC0A78 bclr #$1F,D2 Clear the high bit. FC0A7C move.l D2,A0 Use result as pointer to next node. FC0A7E bra.s FC0A72 Continue processing the list. FC0A80 movem.l D3/D4,$0222(A6) Put KickMemPtr/KickTagPtr back. FC0A86 movem.l (SP)+,D2-D4 FC0A8A rts ; Subroutine to checksum all the entries in a MemList. FC0A8C add.l (A0)+,D0 FC0A8E dbra D1,FC0A8C(PC) FC0A92 rts ; The KickMemPtr points to a list of MemLists, each pointing to ; some number of chunks of memory. This routine steps through ; all the MemLists, allocating all those chunks. If any can't ; be allocated (memory already grabbed by someone else), it returns ; zero. If successful, it returns 1. FC0A94 move.l $0222(A6),D4 Start where the KickMemPtr points. FC0A98 tst.l D4 End of list reached? FC0A9A beq.s FC0ABC If so, return 1 and exit. FC0A9C move.l D4,A2 Point to the current MemList. FC0A9E move.l (A2),D4 Get pointer to the next MemList. FC0AA0 lea $0E(A2),A2 Advance past the MemList header. FC0AA4 move.w (A2)+,D3 Get number of entries in this MemList. FC0AA6 moveq #1,D0 Fake "successful allocation" return code. FC0AA8 bra.s FC0AB4 Enter the loop. ; Allocate all the pieces of memory indicated by this MemList. FC0AAA move.l (A2)+,A1 Get the address of this entry. FC0AAC move.l (A2)+,D0 Get the size of this entry. FC0AAE jsr -$CC(A6) AllocAbs() FC0AB2 tst.l D0 Successful? FC0AB4 dbeq D3,FC0AAA(PC) If so and more entries remain, loop. ; When we come out of the loop, if the zero flag is set, we were ; unable to reclaim a piece of memory specified in the MemList. ; In this case, return zero and exit. Otherwise, we have allocated ; them all and go on to the next MemList. FC0AB8 beq.s FC0ABE If failed, go exit. FC0ABA bra.s FC0A98 Else proces next MemList. FC0ABC moveq #1,D0 Indicate all is OK. FC0ABE rts --------------------------------------------------------------------------- resident = FindResident( name ) D0 A1 --------------------------------------------------------------------------- FC0AC0 movem.l A2/A3,-(SP) FC0AC4 move.l $012C(A6),A2 Get pointer to the resident module table. FC0AC8 move.l A1,A3 ; Outer loop: Step through the table(s) of RomTags, looking ; for one whose name matches the wanted one. FC0ACA move.l (A2)+,D0 Get a RomTag address from the table. FC0ACC beq.s FC0AEA Return zero if end of table reached. FC0ACE bgt.s FC0AD8 If table entry is a link then FC0AD0 bclr #$1F,D0 clear its high bit. FC0AD4 move.l D0,A2 use it as a new table pointer. FC0AD6 bra.s FC0ACA Go to the top of the loop. FC0AD8 move.l D0,A1 Endif FC0ADA move.l A3,A0 Get pointer to desired name. FC0ADC move.l $0E(A1),A1 Point to RomTag's name field. ; Inner loop: Compare the wanted name with that in the RomTag. FC0AE0 cmpm.b (A0)+,(A1)+ Compare a character. FC0AE2 bne.s FC0ACA Back to top of loop if not equal. FC0AE4 tst.b -1(A0) Did we reach the terminating zeros? FC0AE8 bne.s FC0AE0 Compare more characters if not. ; Fall through with the module's address in D0. FC0AEA movem.l (SP)+,A2/A3 FC0AEE rts --------------------------------------------------------------------------- InitCode( startClass, version ) D0 D1 --------------------------------------------------------------------------- ; This function initializes modules from the resident module list. ; The resident module list is one or more tables of RomTag addresses. ; Such tables can be linked together by including the address of the ; next table, with the high bit set, as the last address in a table. ; We are given a set of required flags in D0, and a minimum ; version number in D1. Modules which have flags not set whose bits ; appear in D0, or are of a lower version than D1, will not be ; initialized. FC0AF0 movem.l D2/D3/A2,-(SP) FC0AF4 move.l $012C(A6),A2 Get the ResModules pointer. FC0AF8 move.b D0,D2 Get forbidden flags. FC0AFA move.b D1,D3 Get cutoff version number. FC0AFC move.l (A2)+,D0 Read a module address from the table. FC0AFE beq.s FC0B22 Exit if end of table reached. FC0B00 bgt.s FC0B0A Is the high bit set? If so, it's FC0B02 bclr #$1F,D0 a pointer to another table, so strip FC0B06 move.l D0,A2 the high bit off, point to the next FC0B08 bra.s FC0AFC table, and process it. FC0B0A move.l D0,A1 Check the module's version number FC0B0C cmp.b $0B(A1),D3 against the cutoff. FC0B10 bgt.s FC0AFC Ignore module if too low. FC0B12 move.b $0A(A1),D0 Get the module's flags. FC0B16 and.b D2,D0 Check against mask. FC0B18 beq.s FC0AFC Ignore it if required ones not set. FC0B1A moveq #0,D1 FC0B1C jsr -$66(A6) InitResident() FC0B20 bra.s FC0AFC Process next resident module. FC0B22 movem.l (SP)+,D2/D3/A2 FC0B26 rts --------------------------------------------------------------------------- InitResident( resident, segList ) A1 D1 --------------------------------------------------------------------------- ; This initializes a resident module. The pointer to the module ; is in register A1. If the RT_FLAGS byte at offset 10 from ; the module pointer has the RTF_AUTOINIT flag set, we let the ; module initialize itself by calling its initialization code. ; Otherwise we assume it's a library type of thing, and call ; MakeLibrary with a set of parameters taken from the module. ; If the MakeLibrary succeeds, we add the module to the appropriate ; system list. FC0B28 btst #7,$0A(A1) Check the RTF_AUTOINIT flag. FC0B2E bne.s FC0B3C FC0B30 move.l $16(A1),A1 Get the RT_INIT address. FC0B34 moveq #0,D0 FC0B36 move.l D1,A0 Get the segList pointer. FC0B38 jsr (A1) Call the module's init code. FC0B3A bra.s FC0B7E ; The RTF_AUTOINIT flag was not set, so we MakeLibrary() the ; module instead. Note that the address at RT_INIT points to ; a data structure containing parameters for MakeLibrary(). FC0B3C movem.l A1/A2,-(SP) FC0B40 move.l $16(A1),A1 Get the initialization address. FC0B44 movem.l (A1),D0/A0-A2 Get parameters for MakeLibrary. FC0B48 jsr -$54(A6) MakeLibrary() FC0B4C movem.l (SP)+,A0/A2 FC0B50 move.l D0,-(SP) Store the library pointer. FC0B52 beq.s FC0B7C If zero, just return it and exit. ; The library has been created successfully. FC0B54 move.l D0,A1 Get the library pointer. FC0B56 move.b $0C(A0),D0 Get the module's node type. FC0B5A cmp.b #3,D0 If the node type is NT_DEVICE then FC0B5E bne.s FC0B66 FC0B60 jsr -$01B0(A6) AddDevice(). FC0B64 bra.s FC0B7C FC0B66 cmp.b #9,D0 Else if it is NT_LIBRARY then FC0B6A bne.s FC0B72 FC0B6C jsr -$018C(A6) AddLibrary(). FC0B70 bra.s FC0B7C FC0B72 cmp.b #8,D0 Else if it is NT_RESOURCE then FC0B76 bne.s FC0B7C FC0B78 jsr -$01E6(A6) AddResource(). FC0B7C move.l (SP)+,D0 Endif. FC0B7E rts ; InitStruct entry point to copy one byte several times (-186). FC0B80 move.b (A1)+,D1 Get the byte initially. FC0B82 move.b D1,(A0)+ Copy it the required number of times. FC0B84 dbra D0,FC0B82(PC) FC0B88 bra.s FC0BD6 Back to main loop. ; Entry ponint for invalid InitStruct commands (-176). Guru time. FC0B8A movem.l D7/A5/A6,-(SP) Save registers. FC0B8E move.l #$81000007,D7 Alert number (fatal). FC0B94 move.l 4,A6 Get ExecBase FC0B98 jsr -$6C(A6) Put up the Alert. FC0B9C movem.l (SP)+,D7/A5/A6 This never gets executed. ; InitStruct entry point to copy one longword several times (-154). FC0BA0 move.l A1,D1 Round A1 up to next even address. FC0BA2 addq.l #1,D1 FC0BA4 and.b #$FE,D1 FC0BA8 move.l D1,A1 FC0BAA move.l (A1)+,D1 Get the longword initially. FC0BAC move.l D1,(A0)+ Copy it the required number of times. FC0BAE dbra D0,FC0BAC(PC) FC0BB2 bra.s FC0BD6 Back to main loop. ; InitStruct entry point to copy one word several times (-134). FC0BB4 move.l A1,D1 Round A1 up to next even address. FC0BB6 addq.l #1,D1 FC0BB8 and.b #$FE,D1 FC0BBC move.l D1,A1 FC0BBE move.w (A1)+,D1 Get the word initially. FC0BC0 move.w D1,(A0)+ Copy it the required number of times. FC0BC2 dbra D0,FC0BC0(PC) FC0BC6 bra.s FC0BD6 Back to main loop. --------------------------------------------------------------------------- InitStruct( initTable, memory, size ) A1 A2 D0 --------------------------------------------------------------------------- FC0BC8 move.l A2,A0 Get structure base address. FC0BCA lsr.w #1,D0 Divide size by 2 (get size in words) FC0BCC bra.s FC0BD0 FC0BCE clr.w (A0)+ Loop: Clear the structure's memory. FC0BD0 dbra D0,FC0BCE(PC) FC0BD4 move.l A2,A0 Get structure base address again. FC0BD6 clr.w D0 FC0BD8 move.b (A1)+,D0 Read a byte from the initTable. FC0BDA beq.s FC0C38 If it is zero, we're done. FC0BDC bclr #7,D0 Check and reset offset flag. FC0BE0 beq.s FC0BFC Branch if it was not set. ; Process an offset command (10ssnnnn or 11ssnnnn). FC0BE2 bclr #6,D0 Check and reset byte/rptr flag. FC0BE6 beq.s FC0BF4 Branch if it was not set. FC0BE8 subq.l #1,A1 Back up over command byte. FC0BEA move.l (A1)+,D1 Get cmd byte + 24 bit data. FC0BEC and.l #$FFFFFF,D1 Mask out the command byte. FC0BF2 bra.s FC0BF8 ; Process an offset/byte command (10ssnnnn). FC0BF4 moveq #0,D1 FC0BF6 move.b (A1)+,D1 Get next byte from table into D1. ; Continue here for both offset commands. In each case, A1 now ; points at the next even address in the initTable, and D1 contains ; the offset we have just fetched from it, as a longword. FC0BF8 move.l A2,A0 Get structure base address. FC0BFA add.l D1,A0 Add offset just computed. ; Continue here for all commands, A0 now holds the absolute ; address where the next operand should go, D0 contains what is ; left of the command byte, and A1 points at the current even ; address in the table. FC0BFC move.w D0,D1 Get the command byte FC0BFE lsr.w #3,D1 Shift and mask it so it becomes FC0C00 and.w #$0E,D1 2 * (sdd) FC0C04 move.w FC0C3A(D1.w),D1 Get the jump offset from the table. FC0C08 and.w #$0F,D0 Mask all but (nnnn) out of the command. FC0C0C jmp FC0C3A(D1.w) Jump to the right routine. ; Entry point for copying multiple bytes (-42). FC0C10 move.b (A1)+,(A0)+ Copy one byte. FC0C12 dbra D0,FC0C10(PC) Loop until required number done. FC0C16 move.l A1,D0 Round A1 up to next even address. FC0C18 addq.l #1,D0 FC0C1A bclr #0,D0 FC0C1E move.l D0,A1 FC0C20 bra.s FC0BD6 Go back to main loop. ; Entry point for copying multiple longwords (-24). ; Simply falls through to word copy routine, set up to copy twice as ; many words. An extra 1 must be added to compensate for the effects ; of the "dbra" instruction. FC0C22 add.w D0,D0 D0 = (2 * D0) + 1. FC0C24 addq.w #1,D0 ; Entry point for copying multiple words (-20). FC0C26 move.l A1,D1 Round A1 up to next even address. FC0C28 addq.l #1,D1 FC0C2A and.b #$FE,D1 FC0C2E move.l D1,A1 FC0C30 move.w (A1)+,(A0)+ Move the data. FC0C32 dbra D0,FC0C30(PC) FC0C36 bra.s FC0BD6 Go back to top of main loop. FC0C38 rts ; Dispatch table for InitStruct. FC0C3A FFE8 -24 (sdd = 000) longword, count. FC0C3C FFEC -20 (sdd = 001) word, count. FC0C3E FFD6 -42 (sdd = 010) byte, count. FC0C40 FF50 -176 (sdd = 011) Invalid. FC0C42 FF66 -154 (sdd = 100) longword, repeat. FC0C44 FF7A -134 (sdd = 101) word, repeat. FC0C46 FF46 -186 (sdd = 110) byte, repeat. FC0C48 FF50 -176 (sdd = 111) Invalid. FC0C4A 0000 Padding. ; The following is used to bail out of an interrupt which we should ; have ignored. FC0C4C movem.l (SP)+,D0/D1/A0/A1/A5/A6 FC0C50 rte ; Level 1 Autovector interrupt entry point. ; ----------------------------------------- FC0C52 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0C56 lea DFF000,A0 Point to custom chip register area. FC0C5C move.l 4,A6 Get ExecBase. FC0C60 move.w $1C(A0),D1 Get interrupt enable register. FC0C64 btst #$0E,D1 Check master interrupt enable. FC0C68 beq.s FC0C4C Bail out if no interrupts enabled. FC0C6A and.w $1E(A0),D1 Check for pending & enabled interrupts. FC0C6E btst #0,D1 Serial port transmit interrupt? FC0C72 beq.s FC0C80 FC0C74 movem.l $54(A6),A1/A5 Get IntVects[0] handler data. FC0C7A pea -$24(A6) Push address of ExitIntr() FC0C7E jmp (A5) FC0C80 btst #1,D1 Disk block finished interrupt? FC0C84 beq.s FC0C92 FC0C86 movem.l $60(A6),A1/A5 Get IntVects[1] handler data. FC0C8C pea -$24(A6) Push address of ExitIntr() FC0C90 jmp (A5) FC0C92 btst #2,D1 Software generated interrupt? FC0C96 beq.s FC0CA4 FC0C98 movem.l $6C(A6),A1/A5 Get IntVects[2] handler data. FC0C9E pea -$24(A6) Push address of ExitIntr() FC0CA2 jmp (A5) FC0CA4 bra.s FC0C4C Bail out if nothing found. ; Level 2 Autovector interrupt entry point. ; ----------------------------------------- FC0CA6 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0CAA lea DFF000,A0 See level 1 for comments. FC0CB0 move.l 4,A6 FC0CB4 move.w $1C(A0),D1 FC0CB8 btst #$0E,D1 FC0CBC beq.s FC0C4C FC0CBE and.w $1E(A0),D1 FC0CC2 btst #3,D1 I/O port or timer interrupt? FC0CC6 beq.s FC0CD4 FC0CC8 movem.l $78(A6),A1/A5 Get IntVects[3] handler data. FC0CCE pea -$24(A6) Push address of ExitIntr() FC0CD2 jmp (A5) FC0CD4 bra FC0C4C Bail out if nothing found. ; Level 3 Autovector interrupt entry point. ; ----------------------------------------- FC0CD8 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0CDC lea DFF000,A0 See level 1 for comments. FC0CE2 move.l 4,A6 FC0CE6 move.w $1C(A0),D1 FC0CEA btst #$0E,D1 FC0CEE beq FC0C4C FC0CF2 and.w $1E(A0),D1 FC0CF6 btst #6,D1 Blitter finished? FC0CFA beq.s FC0D08 FC0CFC movem.l $9C(A6),A1/A5 Get IntVects[6] handler data. FC0D02 pea -$24(A6) Push address of ExitIntr() FC0D06 jmp (A5) FC0D08 btst #5,D1 Start of vertical blank? FC0D0C beq.s FC0D1A FC0D0E movem.l $90(A6),A1/A5 Get IntVects[5] handler data. FC0D14 pea -$24(A6) Push address of ExitIntr() FC0D18 jmp (A5) FC0D1A btst #4,D1 Copper interrupt? FC0D1E beq.s FC0D2C FC0D20 movem.l $84(A6),A1/A5 Get IntVects[4] handler data. FC0D26 pea -$24(A6) Push address of ExitIntr() FC0D2A jmp (A5) FC0D2C bra FC0C4C Bail out if nothing found. ; Level 4 Autovector interrupt entry point. ; ----------------------------------------- FC0D30 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0D34 lea DFF000,A0 See level 1 for comments. FC0D3A move.l 4,A6 FC0D3E move.w $1C(A0),D1 FC0D42 btst #$0E,D1 FC0D46 beq FC0C4C FC0D4A and.w $1E(A0),D1 FC0D4E btst #8,D1 Audio channel 1? FC0D52 beq.s FC0D62 FC0D54 movem.l $B4(A6),A1/A5 Get IntVects[8] handler data. FC0D5A pea FC0DA2 Use special ExitIntr() below. FC0D60 jmp (A5) FC0D62 btst #$0A,D1 Audio channel 3? FC0D66 beq.s FC0D76 FC0D68 movem.l $CC(A6),A1/A5 Get IntVects[10] handler data. FC0D6E pea FC0DA2 Use special ExitIntr() below. FC0D74 jmp (A5) FC0D76 btst #7,D1 Audio channel 0? FC0D7A beq.s FC0D8A FC0D7C movem.l $A8(A6),A1/A5 Get IntVects[7] handler data. FC0D82 pea FC0DA2 Use special ExitIntr() below. FC0D88 jmp (A5) FC0D8A btst #9,D1 Audio channel 2? FC0D8E beq.s FC0D9E FC0D90 movem.l $C0(A6),A1/A5 Get IntVects[9] handler data. FC0D96 pea FC0DA2 Use special ExitIntr() below. FC0D9C jmp (A5) FC0D9E bra FC0C4C Bail out if nothing found. ; This routine allows a single invocation of the level 4 interrupt ; handler to service all level 4 interrupts which are pending or ; become pending while one is serviced. FC0DA2 lea DFF000,A0 Point at custom chip register area. FC0DA8 move.l 4,A6 Get ExecBase. FC0DAC move.w #$0780,D1 Mask for all level 4 interrupt bits. FC0DB0 and.w $1C(A0),D1 FC0DB4 and.w $1E(A0),D1 Find enabled and pending level 4 ints. FC0DB8 bne.s FC0D4E If any still pending, go service them. FC0DBA jmp -$24(A6) Otherwise, do ExitIntr() ; Level 5 Autovector interrupt entry point. ; ----------------------------------------- FC0DBE movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0DC2 lea DFF000,A0 See level 1 for comments. FC0DC8 move.l 4,A6 FC0DCC move.w $1C(A0),D1 FC0DD0 btst #$0E,D1 FC0DD4 beq FC0C4C FC0DD8 and.w $1E(A0),D1 FC0DDC btst #$0C,D1 Disk sync interrupt? FC0DE0 beq.s FC0DEE FC0DE2 movem.l $E4(A6),A1/A5 Get IntVects[12] handler data. FC0DE8 pea -$24(A6) Push address of ExitIntr() FC0DEC jmp (A5) FC0DEE btst #$0B,D1 Serial port receive interrupt? FC0DF2 beq.s FC0E00 FC0DF4 movem.l $D8(A6),A1/A5 Get IntVects[11] handler data. FC0DFA pea -$24(A6) Push address of ExitIntr() FC0DFE jmp (A5) FC0E00 bra FC0C4C Bail out if nothing found. ; Level 6 Autovector interrupt entry point. ; ----------------------------------------- FC0E04 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0E08 lea DFF000,A0 See level 1 for comments. FC0E0E move.l 4,A6 FC0E12 move.w $1C(A0),D1 FC0E16 btst #$0E,D1 FC0E1A beq FC0C4C FC0E1E and.w $1E(A0),D1 FC0E22 btst #$0E,D1 Special copper interrupt? FC0E26 beq.s FC0E34 FC0E28 movem.l $FC(A6),A1/A5 Get IntVects[14] handler data. FC0E2E pea -$24(A6) Push address of ExitIntr() FC0E32 jmp (A5) FC0E34 btst #$0D,D1 External level 6 interrupt? FC0E38 beq.s FC0E46 FC0E3A movem.l $F0(A6),A1/A5 Get IntVects[13] handler data. FC0E40 pea -$24(A6) Push address of ExitIntr() FC0E44 jmp (A5) FC0E46 bra FC0C4C Bail out if nothing found. ; Level 7 Autovector interrupt entry point. ; ----------------------------------------- FC0E4A movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0E4E move.l 4,A6 FC0E52 movem.l $0108(A6),A1/A5 Get IntVects[15] handler data. FC0E58 jsr (A5) FC0E5A movem.l (SP)+,D0/D1/A0/A1/A5/A6 FC0E5E rte --------------------------------------------------------------------------- ExitIntr() --------------------------------------------------------------------------- ; This routine is called after an interrupt handler has finished. ; It checks if a task switch is necessary. If not, it returns ; from the interrupt. Otherwise, it drops into the scheduler. ; The initial check for supervisor mode is very important. If ; the CPU was in supervisor mode, then there either was no task ; running (CPU stopped), or the task had already been interrupted ; by a lower priority interrupt. In either case, we may not do ; a task switch. In the former case, it will be done after the ; CPU comes out of the STOP instruction in the dispatcher, and ; in the latter, it will be taken care of by the lowest priority ; interrupt handler (which interrupted the CPU while it was not ; in supervisor mode). FC0E60 btst #5,$18(SP) Check if CPU was in supervisor mode. FC0E66 bne.s FC0E80 If so, just return from interrupt. FC0E68 move.l 4,A6 Get ExecBase. FC0E6C tst.b $0127(A6) See if task switching is disabled. FC0E70 bge.s FC0E80 If so, just return from interrupt. FC0E72 btst #7,$0124(A6) Check the scheduling attention flag. FC0E78 beq.s FC0E80 Return from interrupt if not set. FC0E7A move.w #$2000,SR Enable all interrupts. FC0E7E bra.s FC0E8A FC0E80 movem.l (SP)+,D0/D1/A0/A1/A5/A6 FC0E84 rte --------------------------------------------------------------------------- Schedule() --------------------------------------------------------------------------- ; This is the scheduler. It is called with the current task's ; registers saved on the system stack, as put there by the interrupt ; entry point, and PC/SR as put there by the interrupt itself. ; ; The scheduler checks if the task should be suspended and another ; task run in its place. The following decision is made: ; ; IF the current task has an exception pending THEN ; reschedule the current task, so that it will be redispatched, ; so that the dispatcher can process the exception. ; ELSEIF the TaskReady queue is empty THEN ; the current task is the only runnable task in the system, so ; let it continue running. ; ELSEIF the TaskReady queue contains a higher priority task THEN ; do a task switch. ; ELSEIF the current task's time slice has expired THEN ; reschedule the current task (it may be redispatched right away, ; with a new time slice). ; ELSE ; let the current task keep running. ; ENDIF FC0E86 movem.l D0/D1/A0/A1/A5/A6,-(SP) FC0E8A move.w #$2700,SR Mask all maskable interrupts. FC0E8E bclr #7,$0124(A6) Reset the scheduling attention flag. FC0E94 move.l $0114(A6),A1 Get the current task pointer. FC0E98 btst #5,$0E(A1) Check the task's TB_EXCEPT flag. FC0E9E bne.s FC0EBE FC0EA0 lea $0196(A6),A0 Point to the TaskReady queue. FC0EA4 cmp.l 8(A0),A0 Check if the queue is empty. FC0EA8 beq.s FC0E80 If so, return from interrupt. FC0EAA move.l (A0),A0 Get the queue's head node. FC0EAC move.b 9(A0),D1 Get the head node's priority. FC0EB0 cmp.b 9(A1),D1 Compare to the current task's priority. FC0EB4 bge.s FC0EBE Switch tasks if higher priority. FC0EB6 btst #6,$0124(A6) Check the time slice expired flag. FC0EBC beq.s FC0E80 If not expired, return from interrupt. ; If we get this far, it is necessary to put the current task on ; the TaskReady queue and then run the one at the head of the queue. ; This may be the same one if a TB_EXCEPT is being processed. FC0EBE lea $0196(A6),A0 Point to the TaskReady queue. FC0EC2 bsr FC1634 Enqueue the current task. FC0EC6 move.b #3,$0F(A1) Make the task's state TS_READY. FC0ECC move.w #$2000,SR Enable all interrupts. ; Get the current task's saved registers back. They may have been ; put on the stack when an interrupt occurred, or at the start of ; this routine. FC0ED0 movem.l (SP)+,D0/D1/A0/A1/A5 FC0ED4 move.l (SP),-(SP) Insert some space in the system stack. FC0ED6 move.l -$34(A6),4(SP) Put in the address of Switch(). FC0EDC move.l (SP)+,A6 Get A6 from the stack. FC0EDE rts Go to Switch(). --------------------------------------------------------------------------- Switch() [Version for machines without a numeric coprocessor] --------------------------------------------------------------------------- ; The ExecBase "Switch()" vector points here if no FPP is installed. ; This routine does a task switch. It stores the context of ; the currently running task, then drops into the dispatcher. ; The routine stores the current CPU context on the user ; stack. The status register and program counter are popped from ; the supervisor stack. The current interrupt disable nesting ; level and the user stack pointer are then saved in this task's ; task descriptor. ; If the TB_SWITCH bit is set in the task descriptor, the task's ; TC_SWITCH function is called. FC0EE0 move #$2000,SR Enable all interrupts. FC0EE4 move.l A5,-(SP) Stack A5 on the supervisor stack. FC0EE6 move USP,A5 Get the user stack pointer. FC0EE8 movem.l D0-D7/A0-A6,-(A5) Stack all registers on user stack. FC0EEC move.l 4,A6 Get ExecBase FC0EF0 move.w $0126(A6),D0 Get current interrupt disable level. FC0EF4 move.w #$FFFF,$0126(A6) Set interrupt disable level to -1. FC0EFA move.w #$C000,DFF09A Enable interrupts. FC0F02 move.l (SP)+,$34(A5) Fix A5 in the saved register set. FC0F06 move.w (SP)+,-(A5) Save the status register. FC0F08 move.l (SP)+,-(A5) Save the program counter. FC0F0A lea FC0FA6(PC),A4 Address of context-restore routine for machines without an FPP. FC0F0E move.l $0114(A6),A3 Find the current task descriptor. FC0F12 move.w D0,$10(A3) Store interrupt disable level. FC0F16 move.l A5,$36(A3) Store user stack pointer. FC0F1A btst #6,$0E(A3) Check the TB_SWITCH bit FC0F20 beq.s FC0F3C FC0F22 move.l $42(A3),A5 If TB_SWITCH bit was set, then FC0F26 jsr (A5) call this task's TC_SWITCH function. FC0F28 bra.s FC0F3C --------------------------------------------------------------------------- Dispatch() [Version for machines without a numeric coprocessor] --------------------------------------------------------------------------- ; This routine dispatches the next runnable task, if there is one. ; If the TaskReady queue is empty, the routine waits, stopping ; the processor and checking the queue again each time it resumes ; running (after an interrupt). ; When a runnable task is found, it is dispatched. Its context ; and interrupt disable level are restored, and the TB_LAUNCH ; and TB_EXCEPT flags are checked. If either is set, they are ; handled. FC0F2A lea FC0FA6(PC),A4 Address of context-restore routine for machines without an FPP. FC0F2E move.w #$FFFF,$0126(A6) Initialize interrupt disable level FC0F34 move.w #$C000,DFF09A at -1, and enable interrupts. FC0F3C lea $0196(A6),A0 Point at the TaskReady queue. FC0F40 move #$2700,SR Mask all maskable interrupts. FC0F44 move.l (A0),A3 Check for a task descriptor at FC0F46 move.l (A3),D0 the front of the queue. FC0F48 bne.s FC0F5A ; TaskReady queue is empty. Halt the processor until the next ; interrupt, then check for runnable tasks again. FC0F4A addq.l #1,$0118(A6) Increment the idle counter. FC0F4E bset #7,$0124(A6) Set the rescheduling attention flag. FC0F54 stop #$2000 Enable all interrupts and stop. FC0F56 move.l D0,D0 FC0F58 bra.s FC0F40 Go back and check for runnable tasks. ; We have a runnable task. FC0F5A move.l D0,(A0) Unlink the task descriptor from FC0F5C move.l D0,A1 the TaskReady queue. FC0F5E move.l A0,4(A1) FC0F62 addq.l #1,$011C(A6) Increment the dispatch counter. FC0F66 move.l A3,$0114(A6) Set the current task pointer. FC0F6A move.w $0120(A6),$0122(A6) Initialize the time-slice counter. FC0F70 bclr #6,$0124(A6) Reset the time slice expired flag. FC0F76 move.b #2,$0F(A3) Set the task's state to TS_RUN. FC0F7C move.w $10(A3),$0126(A6) Restore the interrupt disable level. FC0F82 tst.b $0126(A6) FC0F86 bmi.s FC0F90 Disable interrupts if interrupt FC0F88 move.w #$4000,DFF09A disable level >= 0. FC0F90 move #$2000,SR Enable all interrupts. FC0F94 move.b $0E(A3),D0 Get the task's flags. FC0F98 and.b #$A0,D0 Check for TB_EXCEPT or TB_LAUNCH. FC0F9C beq.s FC0FA0 FC0F9E bsr.s FC0FB6 Process the flags if either was set. FC0FA0 move.l $36(A3),A5 Get the user stack pointer. FC0FA4 jmp (A4) Restore the CPU context. ; Context Restore routine (non-FPP version) ; ----------------------------------------- ; Pop the task's CPU context off the user stack, and start it ; running. The program counter and status register are set by ; storing them on the supervisor stack for the "RTE" instruction. FC0FA6 lea $42(A5),A2 Get the user stack pointer. FC0FAA move A2,USP Set it. FC0FAC move.l (A5)+,-(SP) Get the program counter. FC0FAE move.w (A5)+,-(SP) Get the status register. FC0FB0 movem.l (A5),D0-D7/A0-A6 Restore all the other registers. FC0FB4 rte And start running the task. ; Subroutine to handle TB_LAUNCH and TB_EXCEPT. FC0FB6 btst #7,D0 Check the TB_LAUNCH bit. FC0FBA beq.s FC0FC6 FC0FBC move.b D0,D2 If it was set, call the task's FC0FBE move.l $46(A3),A5 TC_LAUNCH routine. FC0FC2 jsr (A5) FC0FC4 move.b D2,D0 Restore D0. FC0FC6 btst #5,D0 Check the TB_EXCEPT bit. FC0FCA bne.s FC0FCE FC0FCC rts Return if it was clear. --------------------------------------------------------------------------- Exception() --------------------------------------------------------------------------- ; This routine handles task-level exception processing. ; It checks whether any signals have occurred which should cause ; a software exception. If so, it calls the task's exception ; processing routine. After this returns, it restores everything ; so that the task itself can be dispatched. FC0FCE bclr #5,$0E(A3) Reset the TB_EXCEPT bit. FC0FD4 move.w #$4000,DFF09A Disable() FC0FDC addq.b #1,$0126(A6) FC0FE0 move.l $1A(A3),D0 Get received signals. FC0FE4 and.l $1E(A3),D0 Compare with exception signals. FC0FE8 eor.l D0,$1E(A3) If any exception signals were set, FC0FEC eor.l D0,$1A(A3) reset them in both places. FC0FF0 subq.b #1,$0126(A6) Enable() FC0FF4 bge.s FC0FFE FC0FF6 move.w #$C000,DFF09A FC0FFE move.l $36(A3),A1 Get the user stack pointer. ; Store tc_Flags, tc_State, tc_IDNestCnt, tc_TDNestCnt on user stack. FC1002 move.l $0E(A3),-(A1) ; If interrupts have been disabled exactly once, then enable them. FC1006 tst.b $0126(A6) FC100A bne.s FC101A FC100C subq.b #1,$0126(A6) FC1010 bge.s FC101A FC1012 move.w #$C000,DFF09A ; Put the address of an exception post-processing routine on the ; user stack. This gets executed when the exception routine ; does an RTS. FC101A move.l #$FC103A,-(A1) Put return address on user stack. FC1020 move A1,USP Set user stack pointer. FC1022 btst #0,$0129(A6) See if this is a plain 68000. FC1028 beq.s FC102E FC102A move.w #$20,-(SP) Make 68010/020 extended stack frame. FC102E move.l $2A(A3),-(SP) Put exception code and a fake status FC1032 clr.w -(SP) word on the supervisor stack. FC1034 move.l $26(A3),A1 Point to the exception handler's data segment. FC1038 rte ; Continue here after the user's exception handling routine has run. FC103A move.l 4,A6 Get ExecBase. FC103E lea FC1046(PC),A5 Where to go in supervisor mode. FC1042 jmp -$1E(A6) Go to supervisor mode. FC1046 lea FC0FA6(PC),A4 Address of context restore routine. FC104A btst #0,$0129(A6) Is this a 68010/020? FC1050 beq.s FC1060 FC1052 addq.l #2,SP If so, handle extended stack frame. FC1054 btst #4,$0129(A6) Do we have a 688881? FC105A beq.s FC1060 FC105C lea FC10F0(PC),A4 If so, use the other context-restore. FC1060 addq.l #6,SP Pop PC and SR from stack. FC1062 move.l $0114(A6),A3 Get current task descriptor. FC1066 or.l D0,$1E(A3) Set the exception signals up again. FC106A move USP,A1 Get the user stack pointer. ; Restore tc_Flags, tc_State, tc_IDNestCnt, tc_TDNestCnt from ; user stack. FC106C move.l (A1)+,$0E(A3) FC1070 move.l A1,$36(A3) Set USP image in task descriptor. FC1074 move.w $10(A3),$0126(A6) Restore interrupt disable level. FC107A tst.b $0126(A6) FC107E bmi.s FC1088 FC1080 move.w #$4000,DFF09A Disable interrupts if needed. FC1088 rts --------------------------------------------------------------------------- Switch() [Version for machines with a 68881 FPP] --------------------------------------------------------------------------- FC108A move #$2000,SR Enable all interrupts. FC108E move.l A5,-(SP) Store A5 on the supervisor stack. FC1090 move USP,A5 Get the user stack pointer. FC1092 movem.l D0-D7/A0-A6,-(A5) Save all registers on user stack. FC1096 move.l 4,A6 Get ExecBase. FC109A move.w $0126(A6),D0 Get current interrupt disable level. FC109E move.w #$FFFF,$0126(A6) Set interrupt disable level to -1. FC10A4 move.w #$C000,DFF09A Enable interrupts. FC10AC move.l (SP)+,$34(A5) Fix A5 in the saved register set. FC10B0 move.w (SP)+,-(A5) Save the status register. FC10B2 move.l (SP)+,-(A5) Save the program counter. ; 68020/68881 specific material. Without documentation for those ; processors, I can't comment this. FC10B4 fsave -(A5) FC10B6 tst.b (A5) FC10B8 beq.s FC10E0 FC10BA moveq #-1,D2 FC10BC move.w (SP),D1 FC10BE and.w #$F000,D1 FC10C2 cmp.w #$9000,D1 FC10C6 bne.s FC10D6 FC10C8 addq.l #2,SP FC10CA move.l (SP)+,-(A5) FC10CC move.l (SP)+,-(A5) FC10CE move.l (SP)+,-(A5) FC10D0 move.w #$20,-(SP) FC10D4 move.w D1,D2 FC10D6 fmovem.x FP0-FP7,-(A5) FC10DA fmovem.l FPCR/FPSR/FPIAR,-(A5) FC10DE move.w D2,-(A5) FC10E0 lea FC10F0(PC),A4 Point to 68881 context restore. ; The rest of the processing for Switch() is the same, so enter ; the "plain" version in the middle. FC10E4 bra FC0F0E --------------------------------------------------------------------------- Dispatch() [Version for machines with a 68881 FPP] --------------------------------------------------------------------------- FC10E8 lea FC10F0(PC),A4 Point to 68881 context-restore. ; The regular Dispatch() can be used for the rest. FC10EC bra FC0F2E ; Special 68881 FPP compatible context restore ; -------------------------------------------- ; 68020/68881 specific material. Without documentation for those ; processors, I can't comment this. FC10F0 move.b (A5),D0 FC10F2 beq.s FC1110 FC10F4 addq.l #2,A5 FC10F6 fmovem.l (A5)+,FPCR/FPSR/FPIAR FC10FA fmovem.x (A5)+,FP0-FP7 FC10FE cmp.b #$90,D0 FC1102 bne.s FC1110 FC1104 addq.l #2,SP FC1106 move.l (A5)+,-(SP) FC1108 move.l (A5)+,-(SP) FC110A move.l (A5)+,-(SP) FC110C move.w #$9020,-(SP) FC1110 frestore (A5)+ FC1112 lea $42(A5),A2 This part is the same as the regular FC1116 move A2,USP context-restore routine. FC1118 move.l (A5)+,-(SP) FC111A move.w (A5)+,-(SP) FC111C movem.l (A5),D0-D7/A0-A6 FC1120 rte --------------------------------------------------------------------------- oldSR = SetSR( newSR, mask) D0 D0 D1 --------------------------------------------------------------------------- FC1122 move.l A5,A0 FC1124 lea FC112E(PC),A5 What to execute in supervisor mode. FC1128 jsr -$1E(A6) Enter supervisor mode. FC112C rts FC112E move.l A0,A5 Now in supervisor mode. Restore A5. FC1130 move.w (SP),A0 Get status register from stack. FC1132 and.w D1,D0 Mask unwanted bits out of newSR. FC1134 not.w D1 FC1136 and.w D1,(SP) Get unchanged bits from old status reg. FC1138 or.w D0,(SP) Or in the bits to be changed. FC113A moveq #0,D0 FC113C move.w A0,D0 Return old status codes in D0. FC113E rte Load status reg. and return to user mode. --------------------------------------------------------------------------- conditions = GetCC() D0 [Version for 68000 machines only] --------------------------------------------------------------------------- ; The ExecBase vector will have been changed not to point here ; unless the CPU is a 68000, since the following instruction would ; bomb with a privilege violation on 68010/020 processors. FC1140 move SR,D0 Get the status register. FC1142 and.w #$FF,D0 Clear all but the condition codes. FC1146 rts --------------------------------------------------------------------------- oldSysStack = SuperState() D0 --------------------------------------------------------------------------- FC1148 move.l A5,A0 FC114A lea FC1154(PC),A5 What to execute in supervisor mode. FC114E jsr -$1E(A6) Enter supervisor mode. FC1152 rts FC1154 move.l A0,A5 Continue here. Restore A5. FC1156 clr.l D0 FC1158 bset #5,(SP) Set supervisor bit in status word. FC115C bne.s FC1172 Do nothing more if it was already set. FC115E move (SP)+,SR Get status register from stack. FC1160 move.l SP,D0 Save supervisor stack pointer. FC1162 move USP,SP Load user stack pointer. FC1164 btst #0,$0129(A6) Check if running on a plain 68000. FC116A beq.s FC116E FC116C addq.l #2,D0 Pop 68010/020 exception info from stack. FC116E addq.l #4,D0 Pop exception return address from stack. FC1170 rts Return to user. FC1172 rte --------------------------------------------------------------------------- UserState( sysStack ) D0 --------------------------------------------------------------------------- FC1174 move.l A5,A0 FC1176 lea FC117E(PC),A5 Where to go in supervisor mode. FC117A jmp -$1E(A6) Enter supervisor mode (just in case). FC117E move.l A0,A5 Restore A5. FC1180 move.w (SP)+,D1 Get status register from stack. FC1182 move SP,USP Copy stack pointer to user stack pointer. FC1184 move.l D0,SP Set the system stack pointer. FC1186 bclr #$0D,D1 Clear the supervisor mode bit. FC118A move D1,SR FC118C rts Return to the user. --------------------------------------------------------------------------- oldInterrupt = SetIntVector( intNumber, interrupt ) D0 D0 A1 --------------------------------------------------------------------------- ; This routine makes an interrupt node the active interrupt node ; for a given interrupt number. This node corresponds to an ; interrupt handler. There can only be one node associated with ; each interrupt number. ; Note: Never try to SetIntVector() one of the interrupts which are ; dispatched as chains of servers. The handler which does this ; does not use regular interrupt vectors or nodes, and it would not ; be possible to hook it up to the interrupt again if it became ; disconnected. FC118E mulu #$0C,D0 Compute address of FC1192 lea $54(A6,D0.w),A0 ExecBase->IntVects[intNumber] FC1196 move.w #$4000,DFF09A Disable() FC119E addq.b #1,$0126(A6) FC11A2 move.l 8(A0),D0 Get pointer to current interrupt node. FC11A6 move.l A1,8(A0) Install pointer to new interrupt node. FC11AA beq.s FC11BA If there is a new node, then FC11AC move.l $0E(A1),0(A0) Install interrupt data pointer. FC11B2 move.l $12(A1),4(A0) Install interrupt code pointer. FC11B8 bra.s FC11C4 Else FC11BA moveq #-1,D1 Set code and data pointers to -1. FC11BC move.l D1,0(A0) FC11C0 move.l D1,4(A0) Endif FC11C4 subq.b #1,$0126(A6) Enable() FC11C8 bge.s FC11D2 FC11CA move.w #$C000,DFF09A FC11D2 rts --------------------------------------------------------------------------- AddIntServer( intNumber, interrupt ) D0 A1 --------------------------------------------------------------------------- ; Adds an interrupt server to the server chain for a given ; interrupt number. The interrupt number must be one of the ; set for which interrupt server lists have been set up. ; The interrupt for which the server is being added will be enabled ; if it is not already enabled. FC11D4 move.l D2,-(SP) FC11D6 move.l D0,D2 Save interrupt number. FC11D8 move.l D0,D1 FC11DA mulu #$0C,D0 Compute FC11DE lea $54(A6,D0.w),A0 ExecBase->IntVects[intNumber].is_Node FC11E2 move.l 0(A0),A0 FC11E6 move.w #$4000,DFF09A Disable() FC11EE addq.b #1,$0126(A6) FC11F2 bsr FC1634 Enqueue the interrupt server. FC11F6 move.w #$8000,D0 Hardware-enable the interrupt FC11FA bset D2,D0 corresponding to the server just added. FC11FC move.w D0,DFF09A FC1202 subq.b #1,$0126(A6) Enable() FC1206 bge.s FC1210 FC1208 move.w #$C000,DFF09A FC1210 move.l (SP)+,D2 FC1212 rts --------------------------------------------------------------------------- RemIntServer( intNumber, interrupt ) D0 A1 --------------------------------------------------------------------------- ; This routine takes an interrupt server off the server chain for ; a given interrupt. The interrupt is disabled if this leaves the ; server chain empty. FC1214 move.l D2,-(SP) FC1216 mulu #$0C,D0 Compute FC121A lea $54(A6,D0.w),A0 ExecBase->IntVects[intNumber].is_Node FC121E move.l 0(A0),A0 FC1222 move.l D0,D2 Save interrupt number and node. FC1224 move.l A0,D1 FC1226 move.w #$4000,DFF09A Disable() FC122E addq.b #1,$0126(A6) FC1232 bsr FC1600 Unlink interrupt server from the chain. FC1236 move.l D1,A0 FC1238 cmp.l 8(A0),A0 Check if the chain is now empty. FC123C bne FC124A FC1240 moveq #0,D1 Chain is empty. Disable the interrupt FC1242 bset D2,D1 corresponding to this node. FC1244 move.w D1,DFF09A FC124A subq.b #1,$0126(A6) Enable() FC124E bge.s FC1258 FC1250 move.w #$C000,DFF09A FC1258 move.l (SP)+,D2 FC125A rts ; The following routine is used at system startup to initialize ; the exec's internal interrupt handlers. ; It initializes the server chains used to dispatch servers for ; I/O and timer, Copper, vertical blank, external level 6, and ; non-maskable interrupts, and establishes vectors to the exec's ; built-in interrupt handlers. ; For each server chain, a 22-byte data structure is built, ; consisting of a list header and 4 words of control data. The ; 5 server chain headers are put into a contiguous 110-byte ; section of memory. The server chains are initialized to empty, ; and the rest of the data structure is initialized with the ; data required to assert, deassert, and cancel the interrupt. FC125C movem.l D2/D3/A2/A3,-(SP) FC1260 move.l #$00006E,D0 110 bytes needed. FC1266 move.l #$010001,D1 Attributes = MEMF_PUBLIC | MEMF_CLEAR. FC126C bsr FC1794 Request memory. FC1270 tst.l D0 See if we got the memory. FC1272 bne.s FC128A FC1274 movem.l D7/A5/A6,-(SP) If not, it's guru time! FC1278 move.l #$81000006,D7 Use this alert number. FC127E move.l 4,A6 Get ExecBase. FC1282 jsr -$6C(A6) Go put up the alert. FC1286 movem.l (SP)+,D7/A5/A6 Never reached. FC128A moveq #4,D2 Loop 5 times (4 + 1 for dbra). FC128C move.l D0,A2 Get pointer to allocated memory. FC128E lea FC12DE(PC),A3 Point to the data table below. ; Loop: Divide the 110 byte data area up into five data ; structures, each consisting of a list header and some control ; words. FC1292 move.l A2,D1 Save pointer to current node. FC1294 move.l A2,(A2) Initialize the node's server chain FC1296 addq.l #4,(A2) to empty. FC1298 clr.l 4(A2) FC129C move.l A2,8(A2) FC12A0 lea $0E(A2),A2 Point to the node's data area. FC12A4 move.w (A3)+,D3 Get interrupt number from table. FC12A6 moveq #0,D0 Make the control word needed to disable FC12A8 bset D3,D0 this interrupt. FC12AA move.w D0,(A2)+ Write it in the node's data area. FC12AC bset #$0F,D0 Make the control word needed to enable FC12B0 move.w D0,(A2)+ this interrupt and store it also. FC12B2 move.w (A3)+,(A2)+ Get the cancel interrupt control word. FC12B4 move.w (A3)+,(A2)+ Move a word of pad data. FC12B6 lea FC12FC(PC),A1 Point to the generic interrupt handler. ; Set up this interrupt in the exec table. The interrupt vector ; is at ExecBase + $54 + 12 * interrupt number. We write the code ; and data addresses only; we don't bother with the node address. FC12BA mulu #$0C,D3 FC12BE movem.l D1/A1,$54(A6,D3.w) FC12C4 dbra D2,FC1292(PC) Loop until all interrupts done. ; Install the address of the software interrupt handler. The ; software interrupt lists have already been cleared earlier in ; the system startup code. FC12C8 move.l #$FC1380,$70(A6) ; Now enable interrupts and exit. Note that only the software ; interrupts are enabled. The interrupts handled by the handler ; below will be enabled if and when servers are put on their ; chains. Interrupts handled external to the exec must be enabled ; by whoever provides the handler. FC12D0 move.w #$8004,DFF09A FC12D8 movem.l (SP)+,D2/D3/A2/A3 FC12DC rts ; Interrupt initialization table. Each line consists of an ; interrupt number, and a control word which is used to cancel ; the interrupt if pending. The last column appears to be padding. FC12DE 0003 0008 0000 FC12E4 0005 0020 0000 FC12EA 0004 0010 0000 FC12F0 000D 2000 0000 FC12F6 000F 0000 0000 ; Generic Interrupt Handler ; ------------------------- ; Each logical interrupt (0-15) has a handler. Some logical ; interrupts are accessible to the user not as handlers, but rather, ; as chains of servers. Most of these (all but the Blitter one) ; use this code, which acts as a handler and dispatches the servers. ; A data structure set up by the previous routine exists for each ; interrupt to store the list header for the server chain, and some ; control words. FC12FC move.w $12(A1),-(SP) FC1300 move.l A2,-(SP) FC1302 move.l (A1),A2 Check the head of the server chain. ; Main loop: Here we dispatch a server from the queue. FC1304 move.l (A2),D0 Is this the end of the chain? FC1306 beq.s FC1316 If so, exit. FC1308 movem.l $0E(A2),A1/A5 Get the server's code and data addresses. FC130E jsr (A5) Call it. ; Servers return with the zero flag indicating whether they have ; taken care of the interrupt. We keep calling servers until ; we either run out or until one returns the zero flag clear. FC1310 bne.s FC1316 If the zero flag is clear, exit. FC1312 move.l (A2),A2 Go to next node in the queue. FC1314 bra.s FC1304 Go back to top of loop. ; Either we ran out of servers, or one of them accepted the ; interrupt. Either way, clear the interrupt and exit. FC1316 move.l (SP)+,A2 FC1318 move.w (SP)+,DFF09C Clear the interrupt. FC131E rts --------------------------------------------------------------------------- Cause( interrupt ) A1 --------------------------------------------------------------------------- FC1320 move.w #$4000,DFF09A Disable() FC1328 addq.b #1,$0126(A6) FC132C cmp.b #$0B,8(A1) Check if node type is already NT_SOFTINT. FC1332 beq.s FC1370 If so, do nothing. FC1334 move.b #$0B,8(A1) Make node type NT_SOFTINT. FC133A moveq #0,D0 FC133C move.b 9(A1),D0 Get node priority. FC1340 and.w #$F0,D0 Truncate to a multiple of 16. FC1344 ext.w D0 Sign extend to a word quantity. FC1346 lea $01D2(A6),A0 Point at middle of ExecBase->SoftInts FC134A add.w D0,A0 Get address of SoftInts entry correspon- ding to this priority (-32,-16,0,16,32). ; Now enqueue the node on the SoftIntList for this priority. FC134C lea 4(A0),A0 FC1350 move.l 4(A0),D0 Get old TailPred pointer. FC1354 move.l A1,4(A0) Set TailPred pointer to new node. FC1358 move.l A0,(A1) Set forward pointer of new node. FC135A move.l D0,4(A1) Set back pointer of new node. FC135E move.l D0,A0 FC1360 move.l A1,(A0) Set forward pointer of old tail node. FC1362 bset #5,$0124(A6) Set the software interrupt pending flag. FC1368 move.w #$8004,DFF09C Generate a level 1 "software" interrupt. FC1370 subq.b #1,$0126(A6) Enable() FC1374 bge.s FC137E FC1376 move.w #$C000,DFF09A FC137E rts ; Software Interrupt Handler ; -------------------------- ; This is the interrupt handler for logical interrupt #2, which ; is used for software interrupts. It will be called as soon after ; the above routine as its interrupt priority will allow. FC1380 move.w #4,DFF09C Clear the interrupt. FC1388 bclr #5,$0124(A6) Clear the software int. pending flag. FC138E bne.s FC1392 If it wasn't set, ignore the interrupt. FC1390 rts FC1392 move.w #4,DFF09A Disable further software interrupts. FC139A bra.s FC13C2 Go and scan the SoftInts table. ; This code is called (from below) when a non-empty SoftIntList ; has been found. The pointer of the list will be in A0. FC139C move.w #$2700,SR Mask all maskable interrupts. FC13A0 move.l (A0),A1 Get the pointer to the first list node. FC13A2 move.l (A1),D0 FC13A4 beq.s FC13AE FC13A6 move.l D0,(A0) Unlink the node from the list. FC13A8 exg A1,D0 FC13AA move.l A0,4(A1) FC13AE move.l D0,A1 FC13B0 move.b #2,8(A1) Make the node type NT_INTERRUPT. FC13B6 move.w #$2000,SR Enable all interrupts. FC13BA movem.l $0E(A1),A1/A5 Get the interrupt code and data. FC13C0 jsr (A5) Call the node's interrupt handler. ; The following scans the SoftInts[] table for non-empty ; SoftIntLists. If it finds one, it executes the code above. FC13C2 moveq #4,D0 Loop 5 times (1 less for dbra). FC13C4 lea $01F2(A6),A0 Start at SoftInts[4] (priority 32). FC13C8 move.w #4,DFF09C Clear the software interrupt. FC13D0 cmp.l 8(A0),A0 See if there are any nodes on this list. FC13D4 bne.s FC139C If so, process the list. FC13D6 lea -$10(A0),A0 Otherwise, go to next lower priority, FC13DA dbra D0,FC13D0(PC) and loop back. ; No (more) nodes found. FC13DE move #$2100,SR FC13E2 move.w #$8004,DFF09A Reenable software interrupts and exit. FC13EA rts --------------------------------------------------------------------------- Disable() --------------------------------------------------------------------------- ; Hardware disable all interrupts, and log the fact that this ; was done in the interrupt disable nesting level counter. FC13EC move.w #$4000,DFF09A FC13F4 addq.b #1,$0126(A6) FC13F8 rts --------------------------------------------------------------------------- Enable() --------------------------------------------------------------------------- ; Decrement the interrupt level nesting counter, and if it goes ; negative, enable interrupts again. FC13FA subq.b #1,$0126(A6) FC13FE bge.s FC1408 FC1400 move.w #$C000,DFF09A FC1408 rts FC140A 0000 Padding. --------------------------------------------------------------------------- AddLibrary( library ) A1 --------------------------------------------------------------------------- FC140C lea $017A(A6),A0 Point to system library list. FC1410 bsr FC1682 Add the library to the list. FC1414 bsr FC1498 Update the library vector checksum. FC1418 rts --------------------------------------------------------------------------- error = RemLibrary( library ) D0 A1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this. FC141A move.l A1,D0 FC141C addq.b #1,$0127(A6) Forbid() FC1420 move.l A6,-(SP) Save ExecBase. FC1422 move.l D0,A6 FC1424 jsr -$12(A6) Call the library's Expunge() function. FC1428 move.l (SP)+,A6 Restore ExecBase. FC142A jsr -$8A(A6) Permit() FC142E rts --------------------------------------------------------------------------- library = OldOpenLibrary( libName ) D0 A1 --------------------------------------------------------------------------- ; This is just OpenLibrary() without the "version" parameter. FC1430 moveq #0,D0 Any version of the library will do. FC1432 jsr -$0228(A6) OpenLibrary() FC1436 rts --------------------------------------------------------------------------- library = OpenLibrary( libName, version ) D0 A1 D0 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this, presumably so it can pull libraries off ; disk if they aren't already in the library list. ; Note how several versions of a library can be in the system ; library list (although the initial RomTag system of putting them ; there will only take the newest one), and this routine will keep ; looking for one new enough to satisfy the request if it finds ; one which is too old. FC1438 move.l D2,-(SP) FC143A move.l D0,D2 FC143C addq.b #1,$0127(A6) Forbid() FC1440 lea $017A(A6),A0 Point to the system library list. FC1444 bsr FC165A FindName() FC1448 tst.l D0 Did we find the library? FC144A beq.s FC145E Return zero and exit if not. FC144C move.l D0,A0 FC144E cmp.w $14(A0),D2 Check the version number. FC1452 bgt.s FC1444 Try to find another one if too old. ; We have an acceptable library. FC1454 move.l A6,-(SP) Save ExecBase. FC1456 move.l A0,A6 Point A6 at the library base address. FC1458 jsr -6(A6) Call the library's Open() function. FC145C move.l (SP)+,A6 Restore ExecBase. FC145E jsr -$8A(A6) Permit() FC1462 move.l (SP)+,D2 FC1464 rts --------------------------------------------------------------------------- CloseLibrary( library ) A1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this. FC1466 addq.b #1,$0127(A6) Forbid() FC146A move.l A6,-(SP) Save ExecBase. FC146C move.l A1,A6 FC146E jsr -$0C(A6) Call the library's Close() function. FC1472 move.l (SP)+,A6 Restore ExecBase. FC1474 jsr -$8A(A6) Permit() FC1478 rts --------------------------------------------------------------------------- oldFunc = SetFunction( library, funcOffset, funcEntry ) D0 A1 A0.W D0 --------------------------------------------------------------------------- FC147A bset #1,$0E(A1) Indicate that library is modified. FC1480 lea 0(A1,A0.w),A0 Compute address of jump instruction. FC1484 move.l 2(A0),-(SP) Get the old jump destination address. FC1488 move.w #$4EF9,(A0) Install a "JMP" instruction. FC148C move.l D0,2(A0) Install the new destination address. FC1490 bsr FC1498 Re-checksum the library. FC1494 move.l (SP)+,D0 Return the previous jump destination. FC1496 rts --------------------------------------------------------------------------- SumLibrary( library ) A1 --------------------------------------------------------------------------- FC1498 btst #2,$0E(A1) Check the "sum used" flag. FC149E beq.s FC14EA If sum not used, then don't bother. FC14A0 addq.b #1,$0127(A6) FC14A4 bclr #1,$0E(A1) Clear the "changed" flag. FC14AA beq.s FC14B0 FC14AC clr.w $1C(A1) If the flag was set, clear the checksum. FC14B0 move.l A1,A0 FC14B2 move.w $10(A1),D0 Get the negative size. FC14B6 lsr.w #1,D0 Divide by 2 (gives size in words). FC14B8 moveq #0,D1 Start the sum at zero. FC14BA bra.s FC14BE ; Loop: Add up all the 16-bit words in the library's jump vector. FC14BC add.w -(A0),D1 FC14BE dbra D0,FC14BC(PC) FC14C2 move.w $1C(A1),D0 Get the old checksum. FC14C6 beq.s FC14E2 FC14C8 cmp.w D0,D1 Old checksum wasn't zero, so compare FC14CA beq.s FC14E6 it to the new checksum. ; Checksums didn't match, so put up an alert. FC14CC movem.l D7/A5/A6,-(SP) FC14D0 move.l #$81000003,D7 Library checksum alert number. FC14D6 move.l 4,A6 FC14DA jsr -$6C(A6) Call the alert function. FC14DE movem.l (SP)+,D7/A5/A6 FC14E2 move.w D1,$1C(A1) Store the new checksum in the library. FC14E6 jsr -$8A(A6) Enable multitasking. FC14EA rts --------------------------------------------------------------------------- library = MakeLibrary( vectors, structure, init, dataSize, segList ) D0 A0 A1 A2 D0 D1 --------------------------------------------------------------------------- FC14EC movem.l D2-D7/A2/A3,-(SP) FC14F0 move.l D0,D2 Size of library data area. FC14F2 move.l A0,D4 Pointer to library vector table. FC14F4 move.l A1,D5 Pointer to initialization structure. FC14F6 move.l A2,D6 Function to call after creating library. FC14F8 move.l D1,D7 SegList (for DOS use). FC14FA move.l A0,D3 Get pointer to vector table. FC14FC beq.s FC151E Skip the following if no vectors. FC14FE move.l A0,A3 FC1500 moveq #-1,D3 FC1502 move.l D3,D0 Check if vector data is absolute or FC1504 cmp.w (A3),D0 relative (first word = -1). FC1506 bne.s FC1512 FC1508 addq.l #2,A3 Relative vectors. Skip over the flag. FC150A cmp.w (A3)+,D0 Count the vectors up to the terminating FC150C dbeq D3,FC150A(PC) flag. D3 holds -(number of vectors + 1) FC1510 bra.s FC1518 FC1512 cmp.l (A3)+,D0 Absolute vectors. Count as above. FC1514 dbeq D3,FC1512(PC) FC1518 not.w D3 Make number of vectors positive. FC151A mulu #6,D3 Multiply by 6. FC151E move.l D2,D0 FC1520 add.l D3,D0 Add size of data area. FC1522 move.l #$010001,D1 MEMF_PUBLIC | MEMF_CLEAR FC1528 jsr -$C6(A6) Request memory for library node. FC152C tst.l D0 See if the memory was allocated. FC152E bne.s FC1536 FC1530 moveq #0,D0 Didn't get any memory. Fail by returning FC1532 bra FC1570 a nil pointer to the caller. FC1536 move.l D0,A3 Point to start of allocated memory. FC1538 add.l D3,A3 Skip over jump vector area. FC153A move.w D3,$10(A3) Install negative size in library node. FC153E move.w D2,$12(A3) Install positive size. FC1542 move.l A3,A0 FC1544 sub.l A2,A2 Clear A2. FC1546 move.l D4,A1 Point at vector table again. FC1548 cmp.w #$FFFF,(A1) Check if vectors are relative. FC154C bne.s FC1552 FC154E addq.l #2,A1 If vectors are relative, skip over flag, FC1550 move.l D4,A2 and set A2 to vector table address. FC1552 bsr FC1576 Install the jump vector. FC1556 tst.l D5 Check if there is an initialization FC1558 beq.s FC1564 structure. Skip the following if not. FC155A move.l A3,A2 FC155C move.l D5,A1 FC155E moveq #0,D0 Do not clear memory before initializing. FC1560 jsr -$4E(A6) Process the initialization structure. FC1564 move.l A3,D0 Get pointer to library node. FC1566 tst.l D6 Check if there is initialization code. FC1568 beq.s FC1570 Skip the following if not. FC156A move.l D6,A1 Get the address of the code. FC156C move.l D7,A0 Get the address of the segList FC156E jsr (A1) Call the initialization code. FC1570 movem.l (SP)+,D2-D7/A2/A3 FC1574 rts --------------------------------------------------------------------------- size = MakeFunctions( vectors, offset ) D0 A1 A2 --------------------------------------------------------------------------- FC1576 move.l A3,-(SP) FC1578 moveq #0,D0 Clear size counter. FC157A move.l A2,D1 Check if vector table is relative. FC157C beq.s FC1594 ; Process a relative vector initialization table. FC157E move.w (A1)+,D1 Get a relative table entry. FC1580 cmp.w #$FFFF,D1 Check if end of table marker. FC1584 beq.s FC15A8 FC1586 lea 0(A2,D1.w),A3 Compute absolute vector address. FC158A move.l A3,-(A0) Install in jump vector. FC158C move.w #$4EF9,-(A0) Install "JMP" instruction. FC1590 addq.l #6,D0 Increment size counter. FC1592 bra.s FC157E ; Process an absolute vector initialization table. FC1594 move.l (A1)+,D1 Get an absolute table entry. FC1596 cmp.l #$FFFFFFFF,D1 Check if end of table marker. FC159C beq.s FC15A8 FC159E move.l D1,-(A0) Install it in the jump table. FC15A0 move.w #$4EF9,-(A0) Install "JMP" instruction. FC15A4 addq.l #6,D0 Increment size counter. FC15A6 bra.s FC1594 FC15A8 move.l (SP)+,A3 Done, return to caller. FC15AA rts --------------------------------------------------------------------------- Insert( list, node, listNode ) A0 A1 A2 --------------------------------------------------------------------------- FC15AC move.l A2,D0 Check if node to insert after is zero. FC15AE beq FC15D8 If so, do an AddHead instead. FC15B2 move.l (A2),D0 See if list node indicates end of list. FC15B4 beq FC15C6 Branch if so. ; If we get this far, A2 must point to a list node. FC15B8 move.l D0,A0 FC15BA movem.l D0/A2,(A1) Set forward and back pointers of new node. FC15BE move.l A1,4(A0) Set back pointer of next node. FC15C2 move.l A1,(A2) Set forward pointer of previous node. FC15C4 rts ; The "Successor" field of the listNode was zero, i.e. listNode ; is really the end of list marker. In this case, insert just ; before listNode, i.e. at the end of the list (undocumented). FC15C6 move.l A2,(A1) Set forward pointer of new node to end. FC15C8 move.l 4(A2),A0 Get old TailPred pointer FC15CC move.l A0,4(A1) Link previous end node to new node. FC15D0 move.l A1,4(A2) Set the TailPred pointer to the new node. FC15D4 move.l A1,(A0) Link this node to the previous end node. FC15D6 rts --------------------------------------------------------------------------- AddHead( list, node ) A0 A1 --------------------------------------------------------------------------- FC15D8 move.l (A0),D0 Get old pointer to first node. FC15DA move.l A1,(A0) Make the first node the new node. FC15DC movem.l D0/A0,(A1) Set forward and back pointers in new node. FC15E0 move.l D0,A0 FC15E2 move.l A1,4(A0) Fix back pointer in previous first node. FC15E6 rts --------------------------------------------------------------------------- AddTail( list, node ) A0 A1 --------------------------------------------------------------------------- FC15E8 lea 4(A0),A0 Point A0 to list's "Tail" field. FC15EC move.l 4(A0),D0 Save old value of TailPred field. FC15F0 move.l A1,4(A0) Make the new node the last node. FC15F4 move.l A0,(A1) Set new node's back pointer to list header. FC15F6 move.l D0,4(A1) Set new node's back pointer. FC15FA move.l D0,A0 FC15FC move.l A1,(A0) Link new node to previous last node. FC15FE rts --------------------------------------------------------------------------- Remove( node ) A1 --------------------------------------------------------------------------- FC1600 move.l (A1),A0 Get pointer to successor node. FC1602 move.l 4(A1),A1 Get pointer to predecessor node. FC1606 move.l A0,(A1) Point predecessor to successor. FC1608 move.l A1,4(A0) Point successor to predecessor. FC160C rts --------------------------------------------------------------------------- node = RemHead( list ) D0 A0 --------------------------------------------------------------------------- FC160E move.l (A0),A1 Get list's head pointer. FC1610 move.l (A1),D0 Get first node's successor. FC1612 beq.s FC161C If zero, list is empty, so return zero. FC1614 move.l D0,(A0) Point head pointer past removed node. FC1616 exg A1,D0 FC1618 move.l A0,4(A1) Point new head node back at list header. FC161C rts --------------------------------------------------------------------------- node = RemTail( list ) D0 A0 --------------------------------------------------------------------------- FC161E move.l 8(A0),A1 Get list's TailPred pointer. FC1622 move.l 4(A1),D0 Check if the last node has a predecessor. FC1626 beq.s FC1632 If not, the list is empty, so return zero. FC1628 move.l D0,8(A0) Point TailPred pointer at second-last node. FC162C exg A1,D0 FC162E move.l A0,(A1) Point second-last node at the list header. FC1630 addq.l #4,(A1) Increment to point at "Tail" field. FC1632 rts --------------------------------------------------------------------------- Enqueue( list, node ) A0 A1 --------------------------------------------------------------------------- FC1634 move.b 9(A1),D1 Get the priority field of the node. FC1638 move.l (A0),D0 Get the head pointer of the queue. ; Loop: Keep skipping nodes until the end of the list is ; reached or the next node has a lower priority. FC163A move.l D0,A0 Point at the current node. FC163C move.l (A0),D0 Check if there is a successor. FC163E beq.s FC1646 If not, we are at the end of the list. FC1640 cmp.b 9(A0),D1 Compare priorities. FC1644 ble.s FC163A Loop until priority is lower than new node's. ; A0 now points at the node to insert before, or at the end ; of the list (i.e. the list header plus 4). FC1646 move.l 4(A0),D0 Get old value of back pointer (or TailPred pointer of list header). FC164A move.l A1,4(A0) Change it to point to the new node. FC164E move.l A0,(A1) Set new node's forward pointer. FC1650 move.l D0,4(A1) Set new node's back pointer to last node skipped, or list header. FC1654 move.l D0,A0 FC1656 move.l A1,(A0) Set list's head field, or forward pointer of previous node, to new node. FC1658 rts --------------------------------------------------------------------------- node = FindName( start, name ) D0 A0 A1 --------------------------------------------------------------------------- FC165A move.l A2,-(SP) FC165C move.l A0,A2 Point to list header or first node. FC165E move.l A1,D1 Save address of match string in D1. FC1660 move.l (A2),D0 FC1662 beq.s FC167C Exit if list is empty. ; Main loop: Check if node pointed to by D0 has the same name ; as the string pointed to by D1. FC1664 move.l D0,A2 Get the address of the node to check. FC1666 move.l (A2),D0 FC1668 beq.s FC167C Exit if this is the end of the list. FC166A move.l $0A(A2),A0 Point A0 at name of this node. FC166E move.l D1,A1 Point A1 at match string. ; Inner loop: Compare the strings. FC1670 cmpm.b (A0)+,(A1)+ Compare one character. FC1672 bne.s FC1664 Skip to next node if not equal. FC1674 tst.b -1(A0) Was this the terminating zero? FC1678 bne.s FC1670 Continue comparing if not. FC167A move.l A2,D0 Got a match - point D0 to the node. FC167C move.l D1,A1 Restore registers and exit. FC167E move.l (SP)+,A2 FC1680 rts ; Protected enqueue and dequeue routines ; -------------------------------------- FC1682 addq.b #1,$0127(A6) Forbid() FC1686 bsr.s FC1634 Enqueue() FC1688 jsr -$8A(A6) Permit() FC168C rts FC168E addq.b #1,$0127(A6) Forbid() FC1692 bsr FC1600 Remove() FC1696 jsr -$8A(A6) Permit() FC169A rts --------------------------------------------------------------------------- memoryBlock = Allocate( freeList, byteSize ) D0 A0 D0 --------------------------------------------------------------------------- FC169C tst.l D0 Zero bytes requested? FC169E beq.s FC16EC If so, just return. FC16A0 movem.l D3/A2/A3,-(SP) FC16A4 addq.l #7,D0 Round D0 up to nearest multiple of 8. FC16A6 and.b #$F8,D0 FC16AA moveq #0,D3 FC16AC cmp.l $1C(A0),D0 Compare D0 to total number of bytes free. FC16B0 bhi FC16E6 If greater, return zero. FC16B4 lea $10(A0),A2 Point at the link to the first MemChunk. ; Loop: Scan the free list for a MemChunk big enough to satisfy ; the request. FC16B8 move.l (A2),D3 Get the pointer to the next MemChunk. FC16BA beq.s FC16E6 If no more MemChunks, return zero. FC16BC move.l D3,A1 FC16BE cmp.l 4(A1),D0 Check D0 against size of this chunk. FC16C2 bls.s FC16C8 If smaller or equal, take it. FC16C4 move.l A1,A2 Otherwise, go to next MemChunk. FC16C6 bra.s FC16B8 Continue searching. ; This is where memory fragmentation occurs. If the block we've ; found is bigger than what we need, we take what we need and make ; a smaller block out of the rest. FC16C8 beq.s FC16DE If sizes are not the same, then FC16CA lea 0(A1,D0.l),A3 Compute address of leftover block. FC16CE move.l (A1),(A3) Move the MemChunk pointer up. FC16D0 move.l 4(A1),D3 Get the current size. FC16D4 sub.l D0,D3 Subtract the allocated amount. FC16D6 move.l D3,4(A3) Put it into the new MemChunk. FC16DA move.l A3,(A2) Link to previous MemChunk (or header). FC16DC bra.s FC16E0 Else FC16DE move.l (A1),(A2) Unlink this MemChunk. Endif FC16E0 sub.l D0,$1C(A0) Decrease free memory value in header. FC16E4 move.l A1,D3 Get address of allocated block. FC16E6 move.l D3,D0 Return zero or address of block. FC16E8 movem.l (SP)+,D3/A2/A3 FC16EC rts ; Routine to put up a "Corrupt Free List" dead-end alert. FC16EE movem.l D7/A5/A6,-(SP) FC16F2 move.l #$81000005,D7 Alert number. FC16F8 move.l 4,A6 Get ExecBase. FC16FC jsr -$6C(A6) Put up the alert. FC1700 movem.l (SP)+,D7/A5/A6 Never reached. --------------------------------------------------------------------------- Deallocate( freeList, memoryBlock, byteSize ) A0 A1 D0 --------------------------------------------------------------------------- FC1704 tst.l D0 See if byte size is zero. FC1706 beq.s FC177C Do nothing if so. FC1708 movem.l D3/A2,-(SP) FC170C move.l A1,D1 FC170E moveq #-8,D3 Truncate block address to nearest FC1710 and.l D3,D1 multiple of 8. FC1712 exg A1,D1 Find out by how much that decreased FC1714 sub.l A1,D1 the address, then add this amount to FC1716 add.l D1,D0 the number of bytes to free. FC1718 addq.l #7,D0 Now round number of bytes to free up to FC171A and.l D3,D0 nearest multiple of 8. FC171C beq FC1778 Exit if the result is zero bytes. ; Block address and size are now nice multiples of 8, so we can ; go ahead and put the block into the free list. FC1720 lea $10(A0),A2 Point at the link to the first MemChunk. FC1724 move.l (A2),D3 Get the address of the first MemChunk. FC1726 beq.s FC1748 Branch if there are no MemChunks. ; Main loop: Find the first MemChunk with an address greater than ; that of our memory block. FC1728 cmp.l D3,A1 Compare addresses. FC172A bcs.s FC1734 Exit loop if right MemChunk found. FC172C beq.s FC177E If addresses are equal, guru time! FC172E move.l D3,A2 FC1730 move.l (A2),D3 Get address of next MemChunk. FC1732 bne.s FC1728 Continue searching. ; A2 now points at the link which comes directly before the position ; where our block must be inserted. First, we check whether this ; is the start of the list. If so, we just link it in. FC1734 moveq #$10,D1 Compute address of MemHeader's link. FC1736 add.l A0,D1 FC1738 cmp.l A2,D1 See if A2 still points there. FC173A beq.s FC1748 If so, insert block at head of the list. ; We are somewhere other than at the start of the list. It is ; possible that we can join the block to the previous MemChunk. ; Try this now. FC173C move.l 4(A2),D3 Compute first address after the FC1740 add.l A2,D3 previous MemChunk. FC1742 cmp.l A1,D3 Compare to address of our new block. FC1744 beq.s FC1752 If equal, join the two together. FC1746 bhi.s FC177E If greater, free list is corrupt. ; Enter here to make a new MemChunk and link it into the free list. FC1748 move.l (A2),(A1) Set new MemChunk's link field. FC174A move.l A1,(A2) Point previous link at the MemChunk. FC174C move.l D0,4(A1) Put the block size into the MemChunk. FC1750 bra.s FC1758 ; Enter here to attach the new block to the previous MemChunk. FC1752 add.l D0,4(A2) Add to previous MemChunk's size. FC1756 move.l A2,A1 Back pointer up to that MemChunk. ; Now the block is taken care of. Either we have built a MemChunk ; for it, or we have attached it to a MemChunk directly before the ; block. Either way, the address of the MemChunk where the block ; now is is in A1. It remains to check whether we can join this ; MemChunk with the next one down the line. FC1758 tst.l (A1) See if there is a next MemChunk. FC175A beq.s FC1774 Exit if not. FC175C move.l 4(A1),D3 Get our MemChunk's size. FC1760 add.l A1,D3 Add to its base address. FC1762 cmp.l (A1),D3 Compare to address of next MemChunk. FC1764 bhi.s FC177E If higher, free list is corrupt. FC1766 bne.s FC1774 If not equal, we can't join them. ; If we get this far, we can join this MemChunk to the next one down ; the line, so we delete the next one and add its size to this one. FC1768 move.l (A1),A2 Get pointer to next MemChunk. FC176A move.l (A2),(A1) Fetch its link and put in our MemChunk. FC176C move.l 4(A2),D3 Get its size. FC1770 add.l D3,4(A1) Add to size of our MemChunk. ; This is where all the paths meet again. FC1774 add.l D0,$1C(A0) Add size of freed block to free counter. FC1778 movem.l (SP)+,D3/A2 FC177C rts ; Error exit routine. Generate a dead-end alert. FC177E movem.l D7/A5/A6,-(SP) FC1782 move.l #$81000009,D7 Alert number. FC1788 move.l 4,A6 Get ExecBase. FC178C jsr -$6C(A6) Go put up the alert. FC1790 movem.l (SP)+,D7/A5/A6 Never reached. --------------------------------------------------------------------------- memoryBlock = AllocMem( byteSize, requirements ) D0 D0 D1 --------------------------------------------------------------------------- ; NOTE: Some other part of the system, presumably DOS, will patch ; itself in ahead of this, presumably so it can throw out unused ; libraries, devices, fonts, etc. when memory runs low. FC1794 addq.b #1,$0127(A6) Forbid() FC1798 movem.l D2/D3/A2,-(SP) FC179C move.l D0,D3 FC179E move.l D1,D2 FC17A0 lea $0142(A6),A2 Point to the system free memory list. ; Loop: Step through the system free memory list looking for ; a MemHeader which can satisfy the memory request. FC17A4 move.l (A2),A2 Get pointer to a MemHeader. FC17A6 tst.l (A2) End of memory list reached? FC17A8 bne.s FC17AE FC17AA moveq #0,D0 If so, return a null pointer and exit. FC17AC bra.s FC17E6 FC17AE move.w $0E(A2),D0 Get the MemHeader's attributes. FC17B2 and.w D2,D0 Check against needed attributes. FC17B4 cmp.w D2,D0 FC17B6 bne.s FC17A4 Go to next MemHeader if not present. ; The current MemHeader has the right attribute flags, now try ; to get a block of the required size out of its free list. FC17B8 move.l A2,A0 Point to the MemHeader. FC17BA move.l D3,D0 Indicate size of block required. FC17BC bsr FC169C Allocate() FC17C0 tst.l D0 Did we get the memory? FC17C2 beq.s FC17A4 If not, go to next MemHeader. ; We got a memory block. Clear it if necessary. FC17C4 btst #$10,D2 Was the MEMF_CLEAR flag set? FC17C8 beq.s FC17E6 Just return if not. FC17CA moveq #0,D1 FC17CC addq.l #3,D3 Convert number of bytes to nearest number FC17CE lsr.l #2,D3 of longwords. FC17D0 move.l D0,A0 Point to the memory block. FC17D2 bra.s FC17D6 Enter the loop at the bottom. ; Loop: Clear the memory block. FC17D4 move.l D1,(A0)+ Clear one longword. FC17D6 dbra D3,FC17D4(PC) Loop back until none remain. FC17DA swap D3 DBRA instruction only uses low 16 bits FC17DC tst.w D3 as program counter, so if any remain FC17DE beq.s FC17E6 set in the upper half of D3, decrement FC17E0 subq.w #1,D3 them manually and loop back. FC17E2 swap D3 FC17E4 bra.s FC17D4 FC17E6 jsr -$8A(A6) Permit() FC17EA movem.l (SP)+,D2/D3/A2 FC17EE rts --------------------------------------------------------------------------- FreeMem( memoryBlock, byteSize ) A1 D0 --------------------------------------------------------------------------- FC17F0 addq.b #1,$0127(A6) Forbid() FC17F4 tst.l D0 Is number of bytes to free zero? FC17F6 beq.s FC1814 If so, just exit. FC17F8 lea $0142(A6),A0 Point to system free memory list. ; Loop: Look for the right MemHeader to put the block back into. FC17FC move.l (A0),A0 Point to the next MemHeader. FC17FE tst.l (A0) End of list reached? ; If no MemHeader can be found to put this block on, something ; is wrong, so it's guru time. FC1800 beq FC16EE Guru time if end of list reached. ; See if the block falls into the address range covered by this ; MemHeader. FC1804 cmp.l $14(A0),A1 Does block start before mh_Lower? FC1808 bcs.s FC17FC If so, try next MemHeader. FC180A cmp.l $18(A0),A1 Does block start after mh_Upper? FC180E bcc.s FC17FC If so, try next MemHeader. ; The block belongs to this MemHeader, so go link it back into ; the free list. FC1810 bsr FC1704 Deallocate() FC1814 jsr -$8A(A6) Permit() FC1818 rts --------------------------------------------------------------------------- attributes = TypeOfMem( address ) D0 A1 --------------------------------------------------------------------------- FC181A addq.b #1,$0127(A6) Forbid() FC181E lea $0142(A6),A0 Point to system free memory list. FC1822 moveq #0,D0 FC1824 move.l (A0),A0 Point to next MemHeader. FC1826 tst.l (A0) End of list reached? FC1828 beq.s FC183A If so, return zero and exit. FC182A cmp.l $14(A0),A1 Check if the block is in the address FC182E bcs.s FC1824 range covered by this MemHeader. FC1830 cmp.l $18(A0),A1 FC1834 bcc.s FC1824 If it is, return the contents of the FC1836 move.w $0E(A0),D0 MemHeader's attribute field. FC183A jsr -$8A(A6) Permit() FC183E rts --------------------------------------------------------------------------- memoryBlock = AllocAbs( byteSize, location ) D0 D0 A1 --------------------------------------------------------------------------- FC1840 addq.b #1,$0127(A6) Forbid() FC1844 movem.l D2-D4/A2/A3,-(SP) FC1848 move.l A1,D2 Get the start address. FC184A and.l #$000007,D2 Truncate down to nearest multiple of 8. FC1850 sub.l D2,A1 FC1852 add.l D2,D0 Add any difference to number of bytes FC1854 addq.l #7,D0 wanted, then round number of bytes FC1856 and.b #$F8,D0 up to nearest multiple of 8. FC185A lea $0142(A6),A0 Point to the system free memory list. ; Loop: Scan through all the MemHeaders in the free list. FC185E move.l (A0),A0 Point to next MemHeader. FC1860 tst.l (A0) End of list reached? FC1862 beq.s FC18CC If so, allocation failed, return zero. ; Check whether the block we want is covered by this MemHeader. FC1864 cmp.l $14(A0),A1 If block starts before this MemHeader's FC1868 bcs.s FC185E area, go on to the next one. FC186A cmp.l $18(A0),A1 If block starts after this MemHeader's FC186E bcc.s FC185E area, go on to next one. ; The desired block starts in the address range covered by this ; MemHeader, so it's either this one or nothing. ; Quick check: If the total number of bytes free in this MemHeader's ; free list is less than the size of the block wanted, then the ; allocation is going to fail anyway. FC1870 cmp.l $1C(A0),D0 Check block size against mh_Free. FC1874 bhi.s FC18CC Allocation failed if higher. FC1876 move.l A1,A3 Get start address of block wanted. FC1878 move.l A1,D2 FC187A add.l D0,D2 Compute end address of block wanted. FC187C lea $10(A0),A2 Point to link to first MemChunk. ; Loop: Find the MemChunk in the free list which contains the ; wanted block. FC1880 move.l (A2),D3 Get pointer to next MemChunk. FC1882 beq.s FC18CC Allocation failed if no more MemChunks. FC1884 move.l D3,A1 FC1886 move.l 4(A1),D4 Get the MemChunk's size. FC188A add.l D3,D4 Compute its end address. FC188C cmp.l D2,D4 Check against needed end address. FC188E bcc.s FC1894 Exit loop if equal or higher. FC1890 move.l A1,A2 FC1892 bra.s FC1880 Go to the next MemChunk. ; We have a MemChunk whose end address is greater than or equal ; to the end address of the block we want. It's either this ; MemChunk or none at all. FC1894 cmp.l A3,D3 Check start addresses. FC1896 bhi.s FC18CC Allocation failed if needed block starts before this MemChunk. ; The block we want is entirely within this MemChunk, so now we ; cut it out and make zero, one or two MemChunks out of what's left. FC1898 sub.l D0,$1C(A0) Remove block size from free count. FC189C sub.l D2,D4 Compare end addresses. FC189E bne.s FC18A4 ; The end addresses of the allocated block and the MemChunk it ; was in were exactly equal. FC18A0 move.l (A1),A0 FC18A2 bra.s FC18B0 ; Memory was left over between the allocated block and the end of ; the MemChunk. Make a new MemChunk out of this and link it into ; the free list. FC18A4 lea 0(A3,D0.l),A0 Compute base address of new MemChunk. FC18A8 move.l (A1),(A0) Store pointer to next MemChunk. FC18AA move.l A0,(A1) Link to previous MemChunk. FC18AC move.l D4,4(A0) Store number of bytes in MemChunk. ; At this point, whatever was left after the block was taken ; care of, and a pointer to the next MemChunk after the block is ; in A0. FC18B0 cmp.l A3,D3 Compare start addresses. FC18B2 beq.s FC18BE ; The block started after the beginning of this MemChunk, so we ; just truncate the MemChunk to contain the leftover memory before ; the allocated block. FC18B4 sub.l A3,D3 FC18B6 neg.l D3 Compute remaining size. FC18B8 move.l D3,4(A1) Store in the MemChunk. FC18BC bra.s FC18C0 All done. ; The block started exactly at the beginning of the MemChunk, so ; the MemChunk must be deleted. FC18BE move.l A0,(A2) Unlink this MemChunk from the chain. FC18C0 move.l A3,D0 Return address of allocated block. FC18C2 movem.l (SP)+,D2-D4/A2/A3 FC18C6 jsr -$8A(A6) Permit() FC18CA rts FC18CC moveq #0,D0 Return zero if allocation failed. FC18CE bra.s FC18C2 --------------------------------------------------------------------------- size = AvailMem( requirements ) D0 D1 --------------------------------------------------------------------------- FC18D0 movem.l D3/A2,-(SP) FC18D4 moveq #0,D3 Initialize free memory counter. FC18D6 lea $0142(A6),A1 Point at the ExecBase->MemList. FC18DA addq.b #1,$0127(A6) Forbid() FC18DE move.l (A1),A1 FC18E0 tst.l (A1) Get address of first MemHeader. FC18E2 beq.s FC1912 Exit if list is empty. FC18E4 move.w $0E(A1),D0 Get this MemHeader's attributes. FC18E8 and.w D1,D0 Mask with required attributes. FC18EA cmp.w D1,D0 Check if all attributes are satisfied. FC18EC bne.s FC18DE Go to next MemHeader if not. FC18EE btst #$11,D1 Are we looking for the largest contiguous block of memory? FC18F2 bne.s FC18FA FC18F4 add.l $1C(A1),D3 If not, just add the size, FC18F8 bra.s FC18DE and loop back. ; We are looking for the largest contiguous block of memory. FC18FA move.l $10(A1),D0 Get address of first MemChunk. FC18FE beq.s FC18DE Loop back if there is no MemChunk. FC1900 move.l D0,A0 FC1902 cmp.l 4(A0),D3 See if this MemChunk is the biggest yet. FC1906 bge.s FC190E FC1908 move.l A0,A2 If it is, keep its base address (why?), FC190A move.l 4(A0),D3 and its size. FC190E move.l (A0),D0 FC1910 bra.s FC18FE Go to next MemChunk. FC1912 jsr -$8A(A6) Permit() FC1916 move.l D3,D0 Return the accumulated or largest size. FC1918 movem.l (SP)+,D3/A2 FC191C rts --------------------------------------------------------------------------- memList = AllocEntry( memList ) D0 A0 --------------------------------------------------------------------------- FC191E movem.l D2/D3/A2/A3,-(SP) FC1922 move.l A0,A2 Save pointer to request MemList. FC1924 moveq #0,D2 Clear loop counter. FC1926 moveq #0,D3 FC1928 move.w $0E(A2),D3 Get the number of MemEntries. FC192C move.l D3,D0 FC192E lsl.l #3,D0 Compute the size of the MemList needed FC1930 add.l #$000010,D0 to keep track of the MemEntries. FC1936 move.l #$010000,D1 Set MEMF_CLEAR. FC193C jsr -$C6(A6) Allocate that amount of memory. FC1940 tst.l D0 If we didn't get it, go exit. FC1942 beq.s FC19A2 FC1944 move.l D0,A3 Point to base of new MemList structure. FC1946 move.w D3,$0E(A3) Put in the number of MemEntries. FC194A lea $10(A2),A2 Point to MemEntries in request MemList. FC194E lea $10(A3),A3 Point to MemEntries in result MemList. For each MemEntry do FC1952 move.l 0(A2),D1 Get its required attributes. FC1956 move.l 4(A2),D0 Get its required size. FC195A move.l D0,4(A3) Store the size in the result list. FC195E beq.s FC1968 If size is not zero then FC1960 jsr -$C6(A6) Allocate the memory. FC1964 tst.l D0 Go exit if unsuccessful. FC1966 beq.s FC198A Endif FC1968 move.l D0,0(A3) Store memory address in result list. FC196C addq.l #8,A2 Go to next request MemEntry. FC196E addq.l #8,A3 Go to next result MemEntry. FC1970 addq.l #1,D2 Increment loop counter. FC1972 cmp.l D2,D3 Compare to number of MemEntries. FC1974 bgt.s FC1952 Endfor. FC1976 lsl.l #3,D2 FC1978 neg.l D2 Compute -(size of MemEntry list). FC197A lea -$10(A2,D2.l),A2 Point A2 back at the request MemList. FC197E lea -$10(A3,D2.l),A3 Point A3 back at the result MemList. FC1982 move.l A3,D0 Return the address of the result MemList. FC1984 movem.l (SP)+,D2/D3/A2/A3 FC1988 rts ; Enter here if one of the MemEntries could not be allocated. FC198A move.l D1,D3 Save size of the allocate which failed. FC198C tst.l D2 Test number of allocated MemEntries. FC198E beq.s FC19A4 Exit if none remaining. FC1990 subq.l #1,D2 Decrement number of MemEntries. FC1992 subq.l #8,A3 Point to the allocated MemEntry. FC1994 move.l 0(A3),A1 Get the address and size of the block FC1998 move.l 4(A3),D0 corresponding to it. FC199C jsr -$D2(A6) Deallocate the block. FC19A0 bra.s FC198C Go back and check for more MemEntries. ; Enter here if the AllocEntry failed, after deallocating anything ; which was allocated before the failure. FC19A2 move.l D1,D3 Get size of the allocate which failed. FC19A4 move.l D3,D0 FC19A6 bset #$1F,D0 Set the high bit. FC19AA bra.s FC1984 Return it to the user. --------------------------------------------------------------------------- FreeEntry( memList ) A0 --------------------------------------------------------------------------- FC19AC movem.l D2/A2/A3,-(SP) FC19B0 move.l A0,A2 Point to the MemList. FC19B2 lea $10(A2),A3 Point to the first MemEntry. FC19B6 move.w $0E(A2),D2 Get number of MemEntries. FC19BA bra.s FC19CC For each MemEntry in the MemList do FC19BC move.l 0(A3),A1 Get the address of the memory block. FC19C0 move.l 4(A3),D0 Get the sizde of the memory block. FC19C4 beq.s FC19CA If size is not zero then FC19C6 jsr -$D2(A6) Deallocate the block. FC19CA addq.l #8,A3 Endif FC19CC dbra D2,FC19BC(PC) Endfor FC19D0 moveq #0,D0 FC19D2 move.w $0E(A2),D0 Get the number of MemEntries again. FC19D6 lsl.l #3,D0 FC19D8 add.l #$000010,D0 Compute the size of the MemList. FC19DE move.l A2,A1 Point to the base of the MemList. FC19E0 jsr -$D2(A6) Deallocate it. FC19E4 movem.l (SP)+,D2/A2/A3 FC19E8 rts --------------------------------------------------------------------------- error = AddMemList( size, attributes, pri, base, name ) D0 D0 D1 D2 A0 A1 --------------------------------------------------------------------------- ; This routine takes a block of memory, builds a MemHeader at the ; start of it, and puts the rest of the block into the MemHeader's ; free list. Then it adds the MemHeader to the system free memory ; list. FC19EA move.l A1,$0A(A0) Store the name in the MemHeader. FC19EE lea $20(A0),A1 Compute first address after MemHeader. FC19F2 move.b #$0A,8(A0) MemHeader's node type is NT_MEMORY. FC19F8 move.b D2,9(A0) Set the MemHeader's priority. FC19FC move.w D1,$0E(A0) Set the memory attributes. FC1A00 move.l A1,D1 FC1A02 addq.l #7,D1 Round the base address of the block up FC1A04 and.b #$F8,D1 to the nearest multiple of 8. FC1A08 exg A1,D1 FC1A0A sub.l A1,D1 Compute by how much it changed, FC1A0C add.l D1,D0 and add this amount to the length. FC1A0E and.b #$F8,D0 Truncate the length to a multiple of 8. FC1A12 sub.l #$000020,D0 Subtract the size of the MemHeader. FC1A18 move.l A1,$10(A0) Store base address as lower bound of FC1A1C move.l A1,$14(A0) memory and link to first MemChunk. FC1A20 move.l A1,D1 FC1A22 add.l D0,D1 Compute upper bound address. FC1A24 move.l D1,$18(A0) Store it in the MemHeader. FC1A28 move.l D0,$1C(A0) Store the amount of free memory. FC1A2C move.l D0,4(A1) Build a MemChunk at the start of free FC1A30 clr.l (A1) memory (clear link, store size). FC1A32 move.l A0,A1 Get base address of MemHeader FC1A34 lea $0142(A6),A0 Point to the system free memory list. FC1A38 bsr FC1682 Put the MemHeader on the list. FC1A3C rts FC1A3E 0000 Padding. ; Data table used to build the exec jump vector table. ; There are 105 entries, corresponding to the 105 exec functions, ; followed by a -1 table end marker. Each entry is a 16-bit ; relative offset from the start of the table. FC1A40 08A008A8 08AC08AC EE6AF420 F44604F8 FC1A50 F4A0F4EA F58EF0B0 F188FAAC FB36F080 FC1A60 F0E81596 08EEF9AC F9BA051A 0520F6E2 FC1A70 F708F734 F74EF794 F7D4F8E0 FC5CFCC4 FC1A80 FD54FE00 FDB0FE90 FEDEFF6C FB6CFB98 FC1A90 FBA8FBC0 FBCEFBDE FBF4FC1A 020802B4 FC1AA0 03340388 03E203D8 04900408 058405BC FC1AB0 054E0574 00D800F0 00F4016E 019C01B6 FC1AC0 01DEF9CC F9DAF9F0 FA26FA3A FA58EC14 FC1AD0 EC22EC26 EC74EC9C EC8AED0E ECB2ED2A FC1AE0 01E801F0 01F407B8 07C207EE 06A8F700 FC1AF0 FDDA131C 1332F9F8 13541374 13C41428 FC1B00 145814CE 14F414E4 14F0EFFC FFAA1504 FC1B10 1500 FC1B12 FFFF End of table marker. FC1B14 FFFF Looks like garbage. FC1B16 0000 --------------------------------------------------------------------------- AddPort( port ) A1 --------------------------------------------------------------------------- FC1B18 lea $14(A1),A0 Address of port's message list. FC1B1C move.l A0,(A0) Initialize the list's head pointer. FC1B1E addq.l #4,(A0) FC1B20 clr.l 4(A0) Initialize the list's Tail field. FC1B24 move.l A0,8(A0) Initialize the list's TailPred pointer. FC1B28 lea $0188(A6),A0 Address of the public message port list. FC1B2C bra FC1682 Safely add port to the list. --------------------------------------------------------------------------- RemPort( port ) A1 --------------------------------------------------------------------------- ; Call a general purpose subroutine which unlinks something from ; its queue while disabling multitasking. FC1B30 bra FC168E --------------------------------------------------------------------------- PutMsg( port, message ) A0 A1 --------------------------------------------------------------------------- FC1B34 move.b #5,8(A1) Make sure message node type is NT_MESSAGE FC1B3A move.l A0,D1 FC1B3C lea $14(A0),A0 Compute address of port's message list FC1B40 move.w #$4000,DFF09A Disable() FC1B48 addq.b #1,$0126(A6) ; Enqueue the message at the end of the port's message list FC1B4C lea 4(A0),A0 Point A0 at port's Tail field. FC1B50 move.l 4(A0),D0 Save pointer to last node in list FC1B54 move.l A1,4(A0) Make new node the last node FC1B58 move.l A0,(A1) New node has no next node FC1B5A move.l D0,4(A1) Link new node back to old last node FC1B5E move.l D0,A0 FC1B60 move.l A1,(A0) Link old last node to new node ; Do whatever needs to be done on message arrival. FC1B62 move.l D1,A1 FC1B64 move.l $10(A1),D1 Get address of message port's task. FC1B68 beq.s FC1B9E Exit if port has no task. FC1B6A move.b $0E(A1),D0 Get port's flag bits. FC1B6E and.w #3,D0 FC1B72 beq.s FC1B8E Decode the flag bits. FC1B74 cmp.b #1,D0 FC1B78 bne.s FC1B82 ; Processing for PA_SOFTINT FC1B7A move.l D1,A1 FC1B7C jsr -$B4(A6) Cause the software interrupt. FC1B80 bra.s FC1B9E ; If PA_IGNORE, do nothing. FC1B82 cmp.b #2,D0 FC1B86 beq.s FC1B9E ; (Undocumented?) processing for mp_Flags = 3. Apparently, ; calls a subroutine at mp_SigTask. FC1B88 move.l D1,A0 FC1B8A jsr (A0) FC1B8C bra.s FC1B9E ; Processing for PA_SIGNAL FC1B8E move.b $0F(A1),D0 Get SigBit. FC1B92 move.l D1,A1 FC1B94 moveq #0,D1 Compute corresponding signal mask. FC1B96 bset D0,D1 FC1B98 move.l D1,D0 FC1B9A jsr -$0144(A6) Signal the task. FC1B9E subq.b #1,$0126(A6) Enable() FC1BA2 bge.s FC1BAC FC1BA4 move.w #$C000,DFF09A FC1BAC rts --------------------------------------------------------------------------- message = GetMsg( port ) D0 A0 --------------------------------------------------------------------------- FC1BAE lea $14(A0),A0 Point A0 at head of port's message list. FC1BB2 move.w #$4000,DFF09A Disable() FC1BBA addq.b #1,$0126(A6) ; Try to dequeue a message from the message list. FC1BBE move.l (A0),A1 Get head pointer into A1. FC1BC0 move.l (A1),D0 FC1BC2 beq.s FC1BCC If list is empty, just return zero. FC1BC4 move.l D0,(A0) FC1BC6 exg A1,D0 Unlink the message from the list. FC1BC8 move.l A0,4(A1) ; Reenable interrupts if necessary and exit. FC1BCC subq.b #1,$0126(A6) Enable() FC1BD0 bge.s FC1BDA FC1BD2 move.w #$C000,DFF09A FC1BDA rts --------------------------------------------------------------------------- ReplyMsg( message ) A1 --------------------------------------------------------------------------- FC1BDC move.l $0E(A1),D0 Get address of reply port. FC1BE0 bne.s FC1BEA FC1BE2 move.b #6,8(A1) No reply port. Set node type to FC1BE8 rts NT_FREEMSG and exit. FC1BEA move.b #7,8(A1) Set node type to NT_REPLYMSG. FC1BF0 move.l D0,A0 FC1BF2 bra FC1B3A Send the message via the reply port. --------------------------------------------------------------------------- message = WaitPort( port ) D0 A0 --------------------------------------------------------------------------- FC1BF6 move.l $14(A0),A1 Get head pointer of port's message list. FC1BFA tst.l (A1) Check if list is empty. FC1BFC bne.s FC1C1A If not empty, return right away. FC1BFE move.b $0F(A0),D1 List was empty. Get signal bit. FC1C02 lea $14(A0),A0 Point A0 at message list. FC1C06 moveq #0,D0 FC1C08 bset D1,D0 Compute signal mask. FC1C0A move.l A2,-(SP) FC1C0C move.l A0,A2 FC1C0E jsr -$013E(A6) Wait() FC1C12 move.l (A2),A1 FC1C14 tst.l (A1) Check message list. FC1C16 beq.s FC1C0E If still empty, go back and wait again. FC1C18 move.l (SP)+,A2 FC1C1A move.l A1,D0 Return first message in the list. FC1C1C rts --------------------------------------------------------------------------- port = FindPort( name ) D0 A1 --------------------------------------------------------------------------- FC1C1E lea $0188(A6),A0 Point to the public port list. FC1C22 jsr -$0114(A6) Search it for a port of the given name. FC1C26 rts --------------------------------------------------------------------------- AddResource( resource ) A1 --------------------------------------------------------------------------- FC1C28 lea $0150(A6),A0 Point to the resource list. FC1C2C bra FC1682 Add the resource to the list. --------------------------------------------------------------------------- RemResource( resource ) A1 --------------------------------------------------------------------------- FC1C30 bra FC168E Unlink the resource from the list. --------------------------------------------------------------------------- resource = OpenResource( resName ) D0 A1 --------------------------------------------------------------------------- FC1C34 lea $0150(A6),A0 Point to the resource list. FC1C38 addq.b #1,$0127(A6) Forbid() FC1C3C bsr FC165A FindName() FC1C40 jsr -$8A(A6) Permit() FC1C44 rts FC1C46 0000 Padding. --------------------------------------------------------------------------- AddTask( task, initialPC, finalPC ) A1 A2 A3 --------------------------------------------------------------------------- FC1C48 moveq #0,D1 FC1C4A move.b #1,$0F(A1) Make the task state TS_ADDED. FC1C50 move.b D1,$0E(A1) Clear the task's flags. FC1C54 move.w #$FFFF,$10(A1) Set IDNestCnt and TDNestCnt to -1. FC1C5A move.l $013C(A6),$12(A1) FC1C60 move.l D1,$16(A1) Task is not waiting for any signals. FC1C64 move.l D1,$1A(A1) Task has not received any signals. FC1C68 move.l D1,$1E(A1) Task does not have any exception signals. FC1C6C move.w $0140(A6),$22(A1) Set allocated traps. FC1C72 move.w D1,$24(A1) No traps are enabled. FC1C76 tst.l $32(A1) Install default system exception handler FC1C7A bne.s FC1C82 if the user has not provided one. FC1C7C move.l $0130(A6),$32(A1) FC1C82 tst.l $2A(A1) FC1C86 bne.s FC1C8E FC1C88 move.l $0134(A6),$2A(A1) FC1C8E move.l $36(A1),A0 Get the initial stack pointer. FC1C92 move.l A3,-(A0) Put the exit code address on the stack. FC1C94 bne.s FC1C9A FC1C96 move.l $0138(A6),(A0) Use system default if no exit code. FC1C9A moveq #$0E,D1 Clear 15 longwords below the process's FC1C9C clr.l -(A0) initial stack pointer, so all registers FC1C9E dbra D1,FC1C9C(PC) will be zero when initially loaded. FC1CA2 clr.w -(A0) Clear the initial status register. FC1CA4 move.l A2,-(A0) Put the initial PC on the stack. FC1CA6 btst #4,$0129(A6) If we have a 68881, then put another FC1CAC beq.s FC1CB2 longword on the stack. FC1CAE moveq #0,D0 FC1CB0 move.l D0,-(A0) FC1CB2 move.l A0,$36(A1) Put the initial stack pointer back. FC1CB6 lea $0196(A6),A0 FC1CBA move.w #$4000,DFF09A Disable() FC1CC2 addq.b #1,$0126(A6) FC1CC6 move.b #3,$0F(A1) Make the task state TS_READY. FC1CCC bsr FC1634 Put the task on the TaskReady queue. FC1CD0 move.l $0196(A6),D0 FC1CD4 subq.b #1,$0126(A6) Enable() FC1CD8 bge.s FC1CE2 FC1CDA move.w #$C000,DFF09A FC1CE2 cmp.l A1,D0 If the task ended up at the front of the FC1CE4 bne.s FC1CEA TaskReady queue, then FC1CE6 jsr -$30(A6) Reschedule() FC1CEA rts ; System default task exit function ; --------------------------------- FC1CEC move.l 4,A6 Get ExecBase. FC1CF0 moveq #0,D0 FC1CF2 move.l D0,A1 Ask for current task to be removed. ; fall through into RemTask. --------------------------------------------------------------------------- RemTask( task ) A1 --------------------------------------------------------------------------- FC1CF4 movem.l D2/D3,-(SP) FC1CF8 move.l A1,D3 Check address of task to be removed. FC1CFA bne.s FC1D02 Branch if not zero. FC1CFC move.l $0114(A6),D3 If zero, use the current task. FC1D00 bra.s FC1D26 FC1D02 cmp.l $0114(A6),A1 If not zero, check if it was the current FC1D06 beq.s FC1D26 task anyway. ; The following is executed only if the task to be removed is not ; the current one. This is because the currently running task isn't ; on a queue anywhere. FC1D08 move.w #$4000,DFF09A Disable() FC1D10 addq.b #1,$0126(A6) FC1D14 bsr FC1600 Unlink the task from its queue. FC1D18 subq.b #1,$0126(A6) FC1D1C bge.s FC1D26 Enable() FC1D1E move.w #$C000,DFF09A FC1D26 move.l D3,A1 Get the address of the task back. FC1D28 move.b #6,$0F(A1) Make the task TS_REMOVED. FC1D2E cmp.l $0114(A6),A1 Check if it is the current task. FC1D32 bne.s FC1D38 FC1D34 addq.b #1,$0127(A6) If so, disable task switching now. FC1D38 lea $4A(A1),A0 Point to allocated memory list. FC1D3C move.l (A0),D2 FC1D3E beq.s FC1D58 Exit if the head pointer is zero, FC1D40 cmp.l 8(A0),A0 or if the tail pointer points back at FC1D44 beq FC1D58 the list header. FC1D48 clr.l (A0) Zero the list head pointer. ; Loop: Release all the memory blocks which the task had allocated. FC1D4A move.l D2,A0 Get pointer to current list node. FC1D4C move.l (A0),D2 Get pointer to next list node. FC1D4E beq FC1D58 Exit if the end of the list was reached. FC1D52 jsr -$E4(A6) FreeEntry() this list node. FC1D56 bra.s FC1D4A Back to the head of the loop. FC1D58 cmp.l $0114(A6),D3 Check if the current task was removed. FC1D5C bne.s FC1D6C If not, indicate success and exit. FC1D5E lea FC1D66(PC),A5 FC1D62 jmp -$1E(A6) Go to supervisor mode. FC1D66 addq.l #6,SP Pop exception data from the stack. FC1D68 jmp -$3C(A6) Dispatch() a new task. FC1D6C moveq #0,D0 If the current task was not removed, FC1D6E movem.l (SP)+,D2/D3 indicate success and return. FC1D72 rts --------------------------------------------------------------------------- task = FindTask( name ) D0 A1 --------------------------------------------------------------------------- FC1D74 move.l A1,D0 See if a name was given. FC1D76 bne.s FC1D7E FC1D78 move.l $0114(A6),D0 If not, use this task. FC1D7C bra.s FC1DC6 FC1D7E lea $0196(A6),A0 Point at the TaskReady queue. FC1D82 move.w #$4000,DFF09A Disable() FC1D8A addq.b #1,$0126(A6) FC1D8E jsr -$0114(A6) Call FindName() to look for the task. FC1D92 tst.l D0 Check if found, return address if so. FC1D94 bne.s FC1DB8 FC1D96 lea $01A4(A6),A0 Task not found, try TaskWait queue. FC1D9A jsr -$0114(A6) Call FindName() to look for the task. FC1D9E tst.l D0 Check if found, return address if so. FC1DA0 bne.s FC1DB8 FC1DA2 move.l $0114(A6),A0 Still not found, compare name with that FC1DA6 move.l $0A(A0),A0 of the current task. FC1DAA cmpm.b (A0)+,(A1)+ FC1DAC bne.s FC1DB8 If names differ, return zero (not found). FC1DAE tst.b -1(A0) FC1DB2 bne.s FC1DAA FC1DB4 move.l $0114(A6),D0 Task was the current task. FC1DB8 subq.b #1,$0126(A6) Enable() FC1DBC bge.s FC1DC6 FC1DBE move.w #$C000,DFF09A FC1DC6 rts --------------------------------------------------------------------------- oldPriority = SetTaskPri( task, priority ) D0 A1 D0 --------------------------------------------------------------------------- FC1DC8 move.w #$4000,DFF09A Disable() FC1DD0 addq.b #1,$0126(A6) FC1DD4 move.b 9(A1),-(SP) Save the task's current priority. FC1DD8 move.b D0,9(A1) Set the task's new priority. FC1DDC cmp.l $0114(A6),A1 Check if it was the current task. FC1DE0 beq.s FC1E00 If so, go reschedule it. FC1DE2 cmp.b #3,$0F(A1) Check if the task was TS_READY. FC1DE8 bne.s FC1E04 If not, we're done. FC1DEA move.l A1,D0 FC1DEC bsr FC1600 Take the task out of the TaskReady queue. FC1DF0 lea $0196(A6),A0 FC1DF4 move.l D0,A1 And put it back in the right place FC1DF6 bsr FC1634 corresponding to its new priority. FC1DFA cmp.l $0196(A6),A1 See if it ended up at the front. FC1DFE bne.s FC1E04 If not, we're done. ; If we get here, either we've changed the priority of the current ; task, or we've moved another task to the front of the TaskReady ; queue. Either way, we have to check if the current task should ; be preempted. FC1E00 jsr -$30(A6) Reschedule() FC1E04 subq.b #1,$0126(A6) FC1E08 bge.s FC1E12 Enable() FC1E0A move.w #$C000,DFF09A FC1E12 moveq #0,D0 FC1E14 move.b (SP)+,D0 Return the previous priority. FC1E16 rts --------------------------------------------------------------------------- oldSignals = SetExcept( newSignals, signalMask ) D0 D0 D1 --------------------------------------------------------------------------- FC1E18 move.l $0114(A6),A1 Get pointer to current task. FC1E1C lea $1E(A1),A0 Point to its SigExcept longword. FC1E20 bra.s FC1E2A Drop into SetSignal. --------------------------------------------------------------------------- oldSignals = SetSignal( newSignals, signalMask ) D0 D0 D1 --------------------------------------------------------------------------- FC1E22 move.l $0114(A6),A1 Get pointer to current task. FC1E26 lea $1A(A1),A0 Point to its SigRecvd longword. ; This code is common to SetExcept and SetSignal. FC1E2A and.l D1,D0 Mask out signals to be left alone. FC1E2C move.w #$4000,DFF09A Disable() FC1E34 addq.b #1,$0126(A6) FC1E38 move.l (A0),-(SP) Save current value of signal word. FC1E3A not.l D1 Make mask of singnals to leave alone. FC1E3C and.l (A0),D1 Get those signals only. FC1E3E or.l D0,D1 Or in the changed signals. FC1E40 move.l D1,(A0) Put the result back in the task. ; Now we drop into Signal(), which will process any new signals ; we may have set in the SigRecvd longword. FC1E42 move.l $1A(A1),D0 Get the SigRecvd data. FC1E46 bra.s FC1E5C Drop into Signal. --------------------------------------------------------------------------- Signal( task, signals ) A1 D0 --------------------------------------------------------------------------- FC1E48 lea $1A(A1),A0 Get the set of received signals. FC1E4C move.w #$4000,DFF09A Disable() FC1E54 addq.b #1,$0126(A6) FC1E58 move.l (A0),-(SP) Store the signals. FC1E5A or.l D0,(A0) Or the new signals into the old ones. ; The code from here down is common to SetExcept, SetSignal, and ; Signal. It checks if the task whose signals are being modified ; should be awakened. FC1E5C move.l $1E(A1),D1 Check the exception signals, FC1E60 and.l D0,D1 and see if any of them have become set. FC1E62 bne.s FC1EAE If so, go process them. FC1E64 cmp.b #4,$0F(A1) See if the task is in the TS_WAIT state. FC1E6A bne.s FC1EBE If not, we're done. FC1E6C and.l $16(A1),D0 See if a signal being waited for has been FC1E70 beq.s FC1EBE set. If not, we are done. ; We have set a signal which the task was currently waiting for, ; so we must awaken it. First, we take it out of the TaskWait ; list then we make it TS_READY, then we put it on the TaskReady ; queue and check if it should preempt the current task. FC1E72 lea $01A4(A6),A0 FC1E76 move.l A1,D0 Save pointer to the task. FC1E78 move.l (A1),A0 Get pointer to the next task in the list. FC1E7A move.l 4(A1),A1 Get pointer to the previous task. FC1E7E move.l A0,(A1) Unlink from the previous task. FC1E80 move.l A1,4(A0) Unlink from the next task. FC1E84 move.l D0,A1 Restore pointer to the task. FC1E86 move.b #3,$0F(A1) Make the task TS_READY. FC1E8C lea $0196(A6),A0 Point to the TaskReady queue. FC1E90 bsr FC1634 Enqueue the task in the right place. FC1E94 cmp.l $0196(A6),A1 Check if it was put at the head of the FC1E98 bne.s FC1EBE TaskReady queue, and exit if not. FC1E9A subq.b #1,$0126(A6) FC1E9E bge.s FC1EA8 Enable() FC1EA0 move.w #$C000,DFF09A FC1EA8 move.l (SP)+,D0 Return old signals to caller eventually. FC1EAA jmp -$30(A6) Reschedule() so the task can run. ; Enter here if we have set an exception signal, or if a previously ; set signal has become an exception signal. FC1EAE bset #5,$0E(A1) Set the task's TB_EXCEPT flag. FC1EB4 cmp.b #4,$0F(A1) See if it is in the TS_WAIT state. ; If the task for which the exception occurred was in the TS_WAIT ; state, make it TS_READY and move it from the TaskWait list to ; the TaskReady queue. Otherwise, just dispatch it. FC1EBA beq.s FC1E72 FC1EBC bra.s FC1E9A ; Exit here if the current task was allowed to keep running (i.e. ; the other task did not preempt it). FC1EBE subq.b #1,$0126(A6) Enable() FC1EC2 bge.s FC1ECC FC1EC4 move.w #$C000,DFF09A FC1ECC move.l (SP)+,D0 Return old signals. FC1ECE rts --------------------------------------------------------------------------- signals = Wait( signalSet ) D0 D0 --------------------------------------------------------------------------- FC1ED0 move.l $0114(A6),A1 Get the pointer to the current task. FC1ED4 move.l D0,$16(A1) Record which signals we are waiting for. FC1ED8 move.w #$4000,DFF09A Disable() FC1EE0 addq.b #1,$0126(A6) FC1EE4 bra.s FC1F1A Enter the loop at the bottom. ; Main loop: We stay here until we have a signal we want. FC1EE6 move.b #4,$0F(A1) Make the task state TS_WAIT. FC1EEC lea $01A4(A6),A0 Point to the TaskWait list. FC1EF0 lea 4(A0),A0 FC1EF4 move.l 4(A0),D0 Unlink the task from the TaskReady FC1EF8 move.l A1,4(A0) queue, and put it in the TaskWait FC1EFC move.l A0,(A1) list. FC1EFE move.l D0,4(A1) FC1F02 move.l D0,A0 FC1F04 move.l A1,(A0) ; Here we block. Calling Switch() gives control to any other ; process. Eventually, someone else doing a Signal() will put us ; back on the TaskReady list, and then we will return from the ; Switch() when our priority comes up again. FC1F06 move.l A5,A0 Save A5. FC1F08 lea -$36(A6),A5 Get ready to call Switch(), but first... FC1F0C jsr -$1E(A6) Enter Supervisor mode. ; We're back. See if we now have a signal we want. FC1F10 move.l A0,A5 Restore A5. FC1F12 move.l $0114(A6),A1 Get pointer to current process. FC1F16 move.l $16(A1),D0 Get the signals we are waiting for. ; We initially enter here to see if we have to block at all, and ; again each time we have been unblocked to see if we can now ; continue running. FC1F1A move.l $1A(A1),D1 Get the signals which are currently set. FC1F1E and.l D0,D1 Check against signals to wait for. FC1F20 beq.s FC1EE6 If not, go back and block again. ; Eventually, we end up here. We now have one or more signals ; that were being waited for. We take these out of the set of ; received signals, since we will return them to the caller. FC1F22 eor.l D1,$1A(A1) Update the set of received signals. FC1F26 subq.b #1,$0126(A6) FC1F2A bge.s FC1F34 Enable() FC1F2C move.w #$C000,DFF09A FC1F34 move.l D1,D0 Return the signals. FC1F36 rts --------------------------------------------------------------------------- Reschedule() --------------------------------------------------------------------------- ; This function is used when it is possible that a task should ; be preempted and another task run in its place. It sets the ; scheduling attention flag to force the scheduler to do its thing ; as soon as possible. If multitasking is disabled, that's all ; it does, since Permit() will do the rest when multitasking is ; turned on again. If interrupts are disabled, it sets the software ; generated interrupt. Since this is not accompanied by setting ; the software interrupt pending flag, it will do nothing but ; run ExitIntr() as soon as the interrupt level allows it. ; ExitIntr() will then cause the outstanding scheduling operation ; to be done. ; Note that part of Permit() is used to switch into supervisor ; mode and call the scheduler. FC1F38 bset #7,$0124(A6) Set the scheduling attention flag. FC1F3E sne D0 Save its previous state. FC1F40 tst.b $0127(A6) Check if multitasking enabled. FC1F44 bge.s FC1F58 If not, exit. FC1F46 tst.b $0126(A6) Check if interrupts enabled. FC1F4A blt.s FC1F74 If so, go and do the scheduling. FC1F4C tst.b D0 Check the (old) scheduling attn flag. FC1F4E bne.s FC1F58 Exit if it was already set. FC1F50 move.w #$8004,DFF09C Assert the software generated interrupt. FC1F58 rts --------------------------------------------------------------------------- Forbid() --------------------------------------------------------------------------- FC1F5A addq.b #1,$0127(A6) Increment the TDNestCnt. FC1F5E rts --------------------------------------------------------------------------- Permit() --------------------------------------------------------------------------- FC1F60 subq.b #1,$0127(A6) Decrement the TDNestCnt. FC1F64 bge.s FC1F80 Exit if still positive. FC1F66 tst.b $0126(A6) Check if interrupts disabled. FC1F6A bge.s FC1F80 Exit if yes. ; The current task has just reenabled multitasking. If the system ; is waiting to switch tasks, now is the time to do it. FC1F6C btst #7,$0124(A6) Check the scheduling attention flag. FC1F72 beq.s FC1F80 Exit if not pending. FC1F74 move.l A5,-(SP) Save A5. FC1F76 lea FC1F82(PC),A5 Set address to go to in supervisor mode. FC1F7A jsr -$1E(A6) Enter supervisor mode. FC1F7E move.l (SP)+,A5 Restore A5 and return. FC1F80 rts ; This is executed in supervisor mode. FC1F82 btst #5,(SP) Check caller's supervisor mode flag. FC1F86 beq.s FC1F8A If the caller was in supervisor mode, FC1F88 rte then don't switch tasks. ; Eventually, this task will be dispatched again, using the program ; counter and status register left on the stack by the supervisor ; mode call. Then it continues running above, pops A5 from the ; stack, and returns to the caller. FC1F8A jmp -$2A(A6) Go and do the scheduling. --------------------------------------------------------------------------- trapNum = AllocTrap( trapNum ) D0 D0 --------------------------------------------------------------------------- FC1F8E move.l $0114(A6),A1 Get pointer to the current task. FC1F92 move.w $22(A1),D1 Get the task's TrapAlloc flags. FC1F96 cmp.b #$FF,D0 See if we want a particular trap number. FC1F9A beq.s FC1FA2 FC1F9C bset D0,D1 If so, set this trap number's flag bit. FC1F9E beq.s FC1FAE If it wasn't set, indicate success. FC1FA0 bra.s FC1FAC It was already set, indicate failure. ; Look for a free trap number. FC1FA2 moveq #$0F,D0 16 traps to check. Start at #15. FC1FA4 bset D0,D1 Try to set this trap's flag bit. FC1FA6 beq.s FC1FAE If not set before, indicate success. FC1FA8 dbra D0,FC1FA4(PC) Loop until all flags checked. FC1FAC moveq #-1,D0 Indicate failure. FC1FAE move.w D1,$22(A1) Put updated trap flags back. FC1FB2 rts --------------------------------------------------------------------------- FreeTrap( trapNum ) D0 --------------------------------------------------------------------------- FC1FB4 move.l $0114(A6),A1 Get pointer to the current task. FC1FB8 move.w $22(A1),D1 Get the task's TrapAlloc flags. FC1FBC bclr D0,D1 Clear the specified flag. FC1FBE move.w D1,$22(A1) Put the flags back. FC1FC2 rts --------------------------------------------------------------------------- signalNum = AllocSignal( signalNum ) D0 D0 --------------------------------------------------------------------------- FC1FC4 move.l $0114(A6),A1 Get pointer to the current task. FC1FC8 move.l $12(A1),D1 Get the task's SigAlloc flags. FC1FCC cmp.b #$FF,D0 See if we want a particular signal. FC1FD0 beq.s FC1FD8 FC1FD2 bset D0,D1 If so, try to set its flag. FC1FD4 beq.s FC1FE6 Indicate success if it was clear. FC1FD6 bra.s FC1FE2 Indicate failure if already set. ; Look for a free signal. FC1FD8 moveq #$1F,D0 32 Signals to check. Start at 31. FC1FDA bset D0,D1 Try to set the signal's flag. FC1FDC beq.s FC1FE6 If it wasn't already set, success. FC1FDE dbra D0,FC1FDA(PC) Otherwise, keep looking. FC1FE2 moveq #-1,D0 Indicate failure. FC1FE4 bra.s FC1FFA FC1FE6 move.l D1,$12(A1) Success. Update allocated signal flags. FC1FEA moveq #-1,D1 FC1FEC bclr D0,D1 Set all but this signal bit in D1. FC1FEE and.l D1,$1A(A1) Make sure this signal isn't set. FC1FF2 and.l D1,$1E(A1) Make sure it's not an exception signal. FC1FF6 and.l D1,$16(A1) Indicate that we are not waiting for it. FC1FFA rts --------------------------------------------------------------------------- FreeSignal( signalNum ) D0 --------------------------------------------------------------------------- FC1FFC move.l $0114(A6),A1 Get pointer to the current task. FC2000 move.l $12(A1),D1 Get the SigAlloc flags. FC2004 bclr D0,D1 Clear the indicated signal bit. FC2006 move.l D1,$12(A1) Put the flags back. FC200A rts ; Subroutines for RawDoFmt() ; -------------------------- ; Find the length of a null-terminated string pointed to by A0. ; For efficiency, the length is counted up as a negative number. FC200C moveq #-1,D2 Start the length at -1. FC200E tst.b (A0)+ Get string character, test for end. FC2010 dbeq D2,FC200E(PC) Count, and loop until end of string. FC2014 neg.l D2 FC2016 subq.w #1,D2 Convert length to correct +ve value. FC2018 rts ; Evaluate a decimal numeric constant pointed to by A4. FC201A clr.l D0 Start the result at 0. FC201C clr.l D2 FC201E move.b (A4)+,D2 Get a character from the input. FC2020 cmp.b #'0',D2 FC2024 bcs.s FC203E FC2026 cmp.b #'9',D2 If not a numeric digit, exit. FC202A bhi.s FC203E FC202C add.l D0,D0 Multiply previous result by 10. FC202E move.l D0,D1 FC2030 add.l D0,D0 FC2032 add.l D0,D0 FC2034 add.l D1,D0 FC2036 sub.b #'0',D2 Convert digit to number 0 - 9. FC203A add.l D2,D0 Add to result. FC203C bra.s FC201E Go evaluate next character. ; Finish up by pointing back at the non-digit character. FC203E subq.l #1,A4 Backspace the input pointer. FC2040 rts ; Convert the number in D4 to its decimal ASCII representation. FC2042 tst.l D4 Is the number zero? FC2044 beq.s FC207A If so, just output "0" and return. FC2046 bmi.s FC204C Is it negative? FC2048 neg.l D4 If not, make it negative. FC204A bra.s FC2050 FC204C move.b #'-',(A5)+ If so, output a "-". ; The minus sign is taken care of, and negative the number to ; be output is in D4. FC2050 lea FC2084,A0 Point at table of divisors. FC2056 clr.w D1 Clear the "non-zero digit" flag. FC2058 move.l (A0)+,D2 Get a divisor from the table. FC205A beq.s FC207A If zero, output last digit and exit. ; Subtract the current divisor from the number as many times as ; possible (actually, add to its negative). FC205C moveq #-1,D0 Start the counter at -1. FC205E add.l D2,D4 Try to add the divisor to D4. FC2060 dbgt D0,FC205E(PC) Loop until D4 is greater than zero. FC2064 sub.l D2,D4 Make the number less than zero again. FC2066 addq.w #1,D0 Increment the counter by 1. ; D0 now contains negative the current digit to output. Discard ; it if it is a leading zero. FC2068 bne.s FC206E If the current digit is zero then FC206A tst.w D1 if no non zero digits have been FC206C beq.s FC2058 output, then discard it. ; Output the digit. FC206E moveq #-1,D1 Set "non-zero digit" flag. FC2070 neg.b D0 Make D0 positive. FC2076 add.b #'0',D0 Convert to an ASCII digit. FC2076 move.b D0,(A5)+ Put it into the buffer. FC2078 bra.s FC2058 Go do the next digit. ; Enter here to output the last digit, or the single "0" if the ; number is zero. FC207A neg.b D4 Make D0 positive. FC207C add.b #'0',D4 Convert to an ASCII digit. FC2080 move.b D4,(A5)+ Put it into the buffer. FC2082 rts ; Table of divisors. FC2084 3B9ACA00 1000000000 decimal. FC2088 05F5E100 100000000 decimal. FC208C 00989680 10000000 decimal. FC2090 000F4240 1000000 decimal. FC2094 000186A0 100000 decimal. FC2098 00002710 10000 decimal. FC209C 000003E8 1000 decimal. FC20A0 00000064 100 decimal. FC20A4 0000000A 10 decimal. FC20A8 00000000 0 decimal. ; Convert the number in D4 to its hexadecimal ASCII representation. FC20AC tst.l D4 Is the number zero? FC20AE beq.s FC207A If so, just output "0" and exit. FC20B0 clr.w D1 Clear "non-zero digit" flag. FC20B2 btst #2,D3 Is the data 32 bits long? FC20B6 bne.s FC20BE FC20B8 moveq #3,D2 If not, output 4 digits, FC20BA swap D4 from the high word of D4. FC20BC bra.s FC20C0 FC20BE moveq #7,D2 If so, output 8 digits. ; Digit output loop. FC20C0 rol.l #4,D4 Rotate leftmost digit into bits 0-3. FC20C2 move.b D4,D0 FC20C4 and.b #$0F,D0 Mask out all but bits 0-3. ; Skip leading zeros. FC20C8 bne.s FC20CE If no non-zero digit has been FC20CA tst.w D1 encountered yet, and this is a zero, FC20CC beq.s FC20E2 skip it. FC20CE moveq #-1,D1 Set "non-zero digit" flag. FC20D0 cmp.b #9,D0 Is the digit greater than 9? FC20D4 bhi.s FC20DC FC20D6 add.b #'0',D0 If not, convert to ASCII numeral. FC20DA bra.s FC20E0 FC20DC add.b #$37,D0 If so, convert to upper case letter. FC20E0 move.b D0,(A5)+ Put digit in buffer. FC20E2 dbra D2,FC20C0(PC) Loop until all digits done. FC20E6 rts --------------------------------------------------------------------------- RawDoFmt( FormatString, DataStream, PutChProc, PutChData ) A0 A1 A2 A3 --------------------------------------------------------------------------- FC20E8 movem.l D2-D6/A2-A5,-(SP) FC20EC link A6,#-$10 Reserve stack space for buffer. FC20F0 move.l A1,-(SP) Store data stream pointer. FC20F2 move.l A0,A4 Point to the format string. FC20F4 move.b (A4)+,D0 Get a byte from the format string. FC20F6 beq.s FC2102 Check for end and exit if found. FC20F8 cmp.b #'%',D0 Check for format specifier. FC20FC beq.s FC210C Process it if found. FC20FE jsr (A2) Otherwise, output the character, FC2100 bra.s FC20F4 and go on to the next one. FC2102 jsr (A2) Output the terminating zero. FC2104 unlk A6 Deallocate the output buffer. FC2106 movem.l (SP)+,D2-D6/A2-A5 FC210A rts ; Enter here if the "%" format specifier was found. Next we check ; for the characters "-", signaling that the printed item should ; be left-aligned in its field, and "0", signaling that leading ; zeros should be attached. FC210C lea -$10(A6),A5 Point to the output buffer. FC2110 clr.w D3 Clear the option flags. FC2112 cmp.b #'-',(A4) Left alignment desired? FC2116 bne.s FC211E FC2118 bset #0,D3 If so, set the corresponding flag, FC211C addq.l #1,A4 and go on to the next character. FC211E cmp.b #'0',(A4) Zero fill desired? FC2122 bne.s FC2128 FC2124 bset #1,D3 If so, set the corresponding flag. FC2128 bsr FC201A Get the field width. FC212C move.w D0,D6 Store it in D6. FC212E clr.l D5 Assume no maximum length. FC2130 cmp.b #'.',(A4) Maximum length specifier? FC2134 bne.s FC213E FC2136 addq.w #1,A4 If so, go on to the next character, FC2138 bsr FC201A and get the maximum length. FC213C move.w D0,D5 Store maximum length. FC213E cmp.b #'l',(A4) 32 bit data? FC2142 bne.s FC214A FC2144 bset #2,D3 If so, set the corresponding flag, FC2148 addq.w #1,A4 and go on to the next character. ; At this point, we have interpreted a format string of the format ; "%-0xxx.yyyl". In D3, bit 0 is set if the "-" was present, bit 1 ; is set if the "0" was present, and bit 2 is set if the "l" ; was present. D6 contains the value of "xxx" (numeric constant), ; and D5 contains the value of "yyy" if present, or 0 if not. ; Now we process the actual format characters: "s" for string, "c" ; for character, "d" for decimal, "x" for hex. In all cases, the ; goal is to build a null-terminated string, pointed to by A0, ; containing the formatted output. FC214A move.b (A4)+,D0 Get the next character. FC214C cmp.b #'d',D0 Decimal output? FC2150 bne.s FC215A Skip to next option if not. FC2152 bsr.s FC2168 Get data item. FC2154 bsr FC2042 Format as decimal number. FC2158 bra.s FC21A2 Output the buffer. FC215A cmp.b #'x',D0 Hexadecimal output? FC215E bne.s FC2188 Skip to next option if not. FC2160 bsr.s FC2168 Get data item. FC2162 bsr FC20AC Format as hexadecimal number. FC2166 bra.s FC21A2 Output the buffer. ; Subroutine to get a number from the data stream. We get either ; a word or a longword, depending on whether an "l" was in the ; format specification. FC2168 btst #2,D3 If data size is 16 bits then FC216C bne.s FC217C FC216E move.l 4(SP),A1 Get data stream pointer. FC2172 move.w (A1)+,D4 Get a word from the data stream. FC2174 move.l A1,4(SP) Put data stream pointer back. FC2178 ext.l D4 Extend to longword. FC217A rts Else FC217C move.l 4(SP),A1 Get data stream pointer. FC2180 move.l (A1)+,D4 Get a longword from data stream. FC2182 move.l A1,4(SP) Put data stream pointer back. FC2186 rts Endif ; Continue here if not formatting a number. FC2188 cmp.b #'s',D0 String output? FC218C bne.s FC2196 If not, skip to next. FC218E move.l (SP),A1 Get data stream pointer. FC2190 move.l (A1)+,A5 Point directly at the string. FC2192 move.l A1,(SP) Put data stream pointer back. FC2194 bra.s FC21A8 Output the string. FC2196 cmp.b #'c',D0 Single character output? FC219A bne FC20FE If not, discard format specifier. FC219E bsr.s FC2168 Get character from input stream. FC21A0 move.b D4,(A5)+ Put it into the buffer. ; Numeric and character output, having put their formatted argument ; into the buffer, meet here. FC21A2 clr.b (A5) Zero-terminate the buffer. FC21A4 lea -$10(A6),A5 Point back to its start. ; All output options continue here. A5 now points to a ; null-terminated string to output. FC21A8 move.l A5,A0 FC21AA bsr FC200C Find the length of the string. FC21AE tst.w D5 Was a maximum length specified? FC21B0 beq.s FC21B6 FC21B2 cmp.w D5,D2 If so, and if the output string is FC21B4 bhi.s FC21B8 longer, set the length to the FC21B6 move.w D2,D5 maximum length. FC21B8 sub.w D5,D6 Compute amount of padding needed. FC21BA bpl.s FC21BE FC21BC clr.w D6 Set to zero if negative. FC21BE btst #0,D3 Was left alignment desired? FC21C2 bne.s FC21CC FC21C4 bsr.s FC21DE If not, output padding first. FC21C6 bra.s FC21CC FC21C8 move.b (A5)+,D0 Loop to copy the string to the output FC21CA jsr (A2) until its end or the given maximum FC21CC dbra D5,FC21C8(PC) number of characters. FC21D0 btst #0,D3 Was left alignment desired? FC21D4 beq FC20F4 FC21D8 bsr.s FC21DE If so, output padding now. FC21DA bra FC20F4 Continue with format string. ; Subroutine to output the right amount of padding. FC21DE move.b #' ',D2 Assume padding with spaces. FC21E2 btst #1,D3 Was zero-fill desired? FC21E6 beq.s FC21F2 FC21E8 move.b #'0',D2 If so, pad with zeros. FC21EC bra.s FC21F2 FC21EE move.b D2,D0 Loop to output the required number FC21F0 jsr (A2) of padding characters. FC21F2 dbra D6,FC21EE(PC) FC21F6 rts --------------------------------------------------------------------------- RawIOInit() --------------------------------------------------------------------------- ; Set the serial port for receiving 8 bit data at 9600 bps. FC21F8 move.w #$0174,DFF032 Set up the SERPER register. FC2200 rts --------------------------------------------------------------------------- RawMayGetChar() --------------------------------------------------------------------------- FC2202 moveq #-1,D0 FC2204 move.w DFF018,D1 Read SERDATR. FC220A btst #$0E,D1 Is a byte in the receive buffer? FC220E beq.s FC2220 If not, return -1 and exit. FC2210 move.w #$0800,DFF09C Clear the serial receive interrupt. FC2218 and.l #$00007F,D1 Get the received character. FC221E move.l D1,D0 Return it to the caller. FC2220 rts ; Subroutine to wait for a character on the serial port. FC2222 bsr.s FC2202 RawMayGetChar() FC2224 tst.l D0 Did we get a character? FC2226 bmi.s FC2222 Continue waiting if not. FC2228 rts Return the character. ; This looks like a C entry point for RawPutChar. FC222A move.l 4(SP),D0 Get the first C parameter. --------------------------------------------------------------------------- RawPutChar() --------------------------------------------------------------------------- ; Don't output code 0, and expand newlines to CRLF. FC222E tst.b D0 Is the character to send zero? FC2230 beq.s FC2272 If so, don't send it. FC2232 move.w D0,-(SP) Save the character. FC2234 cmp.b #$0A,D0 Is it a newline? FC2238 bne.s FC223E FC223A moveq #$0D,D0 If so, send a carriage return first. FC223C bsr.s FC2240 FC223E move.w (SP)+,D0 Get the character back. ; Enter here to send the character in D0 on the serial port. FC2240 move.w DFF018,D1 Read SERDATR. FC2246 btst #$0D,D1 Transmitter ready? FC224A beq.s FC2240 Wait until true. FC224C and.w #$FF,D0 Mask out all but bits 0-7. FC2250 or.w #$0100,D0 Set the stop bit. FC2254 move.w D0,DFF030 Write to SERDAT. ; Handle XON/XOFF and/or escape into the debugger if DEL pressed. FC225A bsr.s FC2202 RawMayGetChar() FC225C cmp.b #$13,D0 Did we get an XOFF? FC2260 bne.s FC2266 FC2262 bsr.s FC2222 If yes, wait for any other character. FC2264 bra.s FC225C FC2266 cmp.b #$7F,D0 Did we get a DEL? FC226A bne.s FC2272 Return if not. FC226C bsr FC232E If so, Debug() FC2270 bra.s FC225C On return, check for XOFF again. FC2272 rts ; C compatible routine to print a string. FC2274 move.l 4(SP),A0 Get first C parameter (string addr.) ; Assembly language entry point (address in A0). FC2278 move.b (A0)+,D0 Get a string character. FC227A beq.s FC228C Exit if is the terminating zero. FC227C cmp.b #$0A,D0 Is it a newline? FC2280 bne.s FC2288 FC2282 moveq #$0D,D0 If so, output a CR first. FC2284 bsr.s FC222E FC2286 moveq #$0A,D0 FC2288 bsr.s FC222E Output the character. FC228A bra.s FC2278 Go on to next character. FC228C rts ; C compatible function to output a hex number. First argument ; is the number, second one is the number of digits. The number ; will be output with one space following. FC228E movem.l 4(SP),D0/D1 Get C parameters. ; Assembly language entry point. FC2294 movem.l D2/D3,-(SP) FC2298 move.l D0,D2 FC229A moveq #8,D3 FC229C sub.w D1,D3 Compute 8 - number of digits. FC229E bra.s FC22A2 Loop that many times, rotating the FC22A0 rol.l #4,D2 number left by a digit each time, FC22A2 dbra D3,FC22A0(PC) to left-align the number in D2. FC22A6 move.w D1,D3 Get number of digits. FC22A8 bra.s FC22C2 FC22AA rol.l #4,D2 Shift current digit into bits 0-3. FC22AC moveq #$0F,D0 FC22AE and.b D2,D0 Extract bits 0-3 from the number. FC22B0 cmp.b #9,D0 Numeric or alphabetic digit? FC22B4 bls.s FC22BA FC22B6 add.b #7,D0 If alphabetic, add ('A'-'9'). FC22BA add.b #'0',D0 Convert to ASCII digit. FC22BE bsr FC222E Output the digit. FC22C2 dbra D3,FC22AA(PC) Loop until all digits done. FC22C6 moveq #$20,D0 FC22C8 bsr FC222E Output a space. FC22CC movem.l (SP)+,D2/D3 FC22D0 rts ; Entry point to do a RawDoFmt() to the serial port. FC22D2 move.l A2,-(SP) Save A2. FC22D4 lea FC222E(PC),A2 Point A2 to RawPutChar() function. FC22D8 bsr FC20E8 RawDoFmt() FC22DC move.l (SP)+,A2 Restore A2. FC22DE rts --------------------------------------------------------------------------- Open() --------------------------------------------------------------------------- ; This gets executed if someone actually opens "exec.library". FC22E0 move.l A6,D0 Return ExecBase. FC22E2 addq.w #1,$20(A6) Increment exec.library open count. FC22E6 rts --------------------------------------------------------------------------- Close() --------------------------------------------------------------------------- ; This gets executed if someone tries to close "exec.library". FC22E8 subq.w #1,$20(A6) Decrement exec.library open count. --------------------------------------------------------------------------- Expunge() --------------------------------------------------------------------------- ; This gets executed if someone tries to Expunge() the exec. ; Needless to say, we won't do anything of the sort, but we'll make ; the caller happy by returning zero. ; The reserved jump vector (at ExecBase - 24) also points here. FC22EC moveq #0,D0 FC22EE rts ; ROM-Wack ; -------- ; This is the Amiga's ROM resident mini-debugger. The following ; string is sent out the serial port when it starts up. FC22F0 LF, "rom-wack", 00 ; ROM-Wack has a private, 236 byte data area at $000200. The ; following is a memory map of this area. Addresses are given as ; hex offsets from $000200. ;------------------------------------------------------------------- ; 00 (32 bit) Pointer to current key bindings. ; 04 (32 bit) Saved key binding pointer if not using main ones. ; 08 (32 bit) Value of last number entered by the user. ; 0C (32 bit) The "current address" for all operations. ; 10 - 13 (not used). ; 14 (32 bit) The current "frame size". ; 18 (32 bit) The upper limit address for searches and fills. ; 1C (16 bit) Number of characters in the input buffer. ; 1E (8 bit) Flag indicating whether the "frame" should be ; redisplayed after a command has executed. ; 1F (8 bit) Flag indicating whether we are in "alter" mode. ; 20 (16 bit) Flag indicating whether there is unprocessed data ; in the buffer (0 if yes, 1 if no). ; 22 (16 bit) Number of digits in the number most recently entered. ; 24 (16 bit) Flag indicating whether a number is being gathered as ; a parameter to a command, or being entered unprompted ; (in which case it becomes the current address). ; 26 (32 bit) Indirection stack pointer (for following pointers). ; 2A - 4F (not used). ; 50 - 81 Input buffer for user commands. ; 82 (16 bit) Last character typed by the user. ; 84 (32 bit) Pointer to data area on the stack, holding CPU and ; process related information (map farther down) ; 88 (16 bit) Instruction to use for breakpoints (TRAP #15). ; 8A - E9 Breakpoint table. Each entry consists of an address ; where an instruction was replaced with TRAP #15, and ; the word which had been there before. ; EA (16 bit) Value to be written to INTENA to restore serial ; port interrupts to their original state. ;------------------------------------------------------------------- ; This gets called from the exec initialization code. FC22FA move.l A6,-(SP) Save ExecBase. FC22FC move.l #$000200,A6 Point to ROM-Wack's data area. FC2302 bsr FC2472 Initialize it. FC2306 move.l (SP)+,A6 Restore ExecBase. FC2308 move.l #$FC2342,$42(A6) Install default ExecBase->DebugEntry. FC2310 move.l #$FC232E,-$70(A6) Install default Debug() vector. FC2318 bsr FC21F8 RawIOInit() FC231C rts ; Special exception handlers for ROM-Wack ; --------------------------------------- ; ROM-Wack trace exception handler. FC231E move.l #$000009,-(SP) Push "Trace" exception number. FC2324 bra.s FC2342 Enter the debugger. ; ROM-Wack breakpoint exception handler. A "TRAP #15" instruction ; is used for the breakpoint. FC2326 move.l #$00002F,-(SP) Push "TRAP #15" exception number. FC232C bra.s FC2342 Enter the debugger. --------------------------------------------------------------------------- Debug() --------------------------------------------------------------------------- ; This entry point is used when an actual function call to Debug() ; is made. We set up the supervisor stack to look like it would ; after an exception handled by the exec exception entry points. FC232E move.l A5,-(SP) Save A5. FC2330 lea FC2338(PC),A5 Where to go in supervisor mode. FC2334 jmp -$1E(A6) Supervisor() ; We now have an exception stack frame from the Supervisor() call. FC2338 move USP,A5 Pop the return address from the FC233A move.l (A5)+,-(SP) Debug() call from the user stack. FC233C move A5,USP FC233E move.l (SP)+,A5 Get the return address back. FC2340 clr.l -(SP) Fake exception number zero. ; Now the supervisor and user stacks look as if an exception had ; occurred and was handled by the exec, with the difference that ; the original value of A5 is on the supervisor stack, and A5 now ; contains the return address from the Debug() call. ; Exception entry point. ; ---------------------- ; The debugger is entered here with the stacks already set up as ; above (by the system exception handler). First, we verify if ; the stack is even working (pointing at RAM). FC2342 move.l #$F1E2D3C4,-(SP) Put a signature on the stack. FC2348 cmp.l #$F1E2D3C4,(SP)+ Check if it can be read back. FC234E beq.s FC235E ; A signature pushed on the supervisor stack could not be read ; back, so we are in serious trouble. Initialize the stack at ; the top of the first 256K of chip memory. Put a fake exception ; stack frame on the new stack. FC2350 move.l #$040000,SP Start stack at 256K. FC2356 clr.l -(SP) Fake program counter. FC2358 clr.w -(SP) Fake status register. FC235A clr.l -(SP) Push exception number -1. FC235C not.l (SP) ; We now have a working supervisor stack with the exception ; number and stack frame on it. FC235E movem.l D0-D7/A0-A6,-(SP) Save most of the CPU registers. FC2362 lea $3C(SP),A5 Point A5 at the exception number. FC2366 lea -$16(SP),SP Reserve 22 bytes of stack space, FC236A move.l SP,A4 and point A4 to the bottom of this. FC236C clr.l $12(A4) FC2370 move.l (A5)+,D3 Get the exception number. FC2372 move.l D3,$0E(A4) Store it. FC2376 move.l A5,$0A(A4) Store supervisor stack pointer. FC237A move USP,A0 FC237C move.l A0,6(A4) Store user stack pointer. ; When a 680x0 hits an exception, it pushes the program counter, then ; the status register, onto the supervisor stack. For bus and ; address errors, however, more information is saved. On 68010 and ; 68020 processors, this comes before the program counter and status ; register, i.e. the stack pointer after an exception always points ; at these. On the 68000, however, 8 bytes of other information ; are pushed on the stack AFTER the PC and SP. The following code ; compensates for this. FC2380 bsr FC0546 Check CPU/FPP configuration. FC2384 tst.b D0 Is it a plain vanilla 68000? FC2386 bne.s FC2396 FC2388 cmp.w #3,D3 Was it an address error? FC238C bgt.s FC2396 FC238E cmp.w #2,D3 Was it a bus error? FC2392 blt.s FC2396 FC2394 addq.l #8,A5 If either, skip past bus error info. ; For all CPUs, A5 now points to where the status register and ; program counter are stored on the supervisor stack. FC2396 btst #5,(A5) Check the supervisor mode bit. FC239A bne.s FC23A6 If it was set, FC239C move.l 4,A0 get ExecBase, FC23A0 move.l $0114(A0),$12(A4) and get the current task pointer. FC23A6 move.w (A5)+,4(A4) Get and store the status register. FC23AA move.l (A5),0(A4) Get and store the program counter. ; Time for a summary (so I don't get confused). A4 currently ; points at a data structure, on the supervisor stack, containing ; the following: ; (60 bytes) Register dump (D0-D7, A0-A6). ; (32 bit) Current task pointer or zero. ; (32 bit) Number of the exception that got us here (see below). ; (32 bit) Saved supervisor stack pointer. ; (32 bit) Saved user stack pointer. ; (16 bit) Saved status register (from exception stack frame). ; (32 bit) Saved program counter (from exception stack frame). ; If the exception number is zero, Debug() was used to get here. ; If the exception number is -1, we somehow got here, but the ; supervisor stack pointer was clobbered and not pointing to RAM. ; In this case, we have just set it to 256K, and the saved ; program counter and status register are invalid. FC23AE move.l #$000200,A6 Point to ROM-Wack's data area. ; Disable serial port interrupts, and make a control word which, ; when written to INTENA, will return them to their original status. FC23B4 move.w DFF01C,$EA(A6) Store interrupt enable status. FC23BC move.w #$0801,D0 Disable serial port interrupts. FC23C0 move.w D0,DFF09A FC23C6 bset #$0F,D0 Make the control word to be used FC23CA and.w D0,$EA(A6) to restore those two interrupts. FC23CE bsr FC21F8 RawIOInit() FC23D2 lea FC22F0(PC),A0 FC23D6 bsr FC2278 Print a newline and "rom-wack". FC23DA move.l A4,$84(A6) Save pointer to stack-resident data. FC23DE moveq #-2,D2 Make the saved exception program FC23E0 and.l 0(A4),D2 counter even (if not already so), FC23E4 move.l D2,0(A4) and put it back. FC23E8 move.l D2,$0C(A6) Set the "current address" there. FC23EC cmp.l #$00002F,$0E(A4) Did a TRAP #15 get us here? FC23F4 bne.s FC23FE Skip the following if not. ; Special handling for breakpoints. Back the PC up by 2 (over ; the TRAP #15 instruction used for the breakpoint), and clear ; the breakpoint (restore the original instruction). FC23F6 subq.l #2,$0C(A6) Back up to breakpoint address. FC23FA bsr FC28A2 "clear" the breakpoint. FC23FE move.l $0C(A6),0(A4) Update the saved program counter. FC2404 move.l A4,A1 Point to the stack-resident data. ; Install the exception vectors needed for breakpoints and ; single-stepping. FC2406 move.l #$FC2326,$BC Install TRAP #15 exception vector. FC240E move.l #$FC231E,$24 Install "Trace" exception vector. FC2416 move.l #$01000000,$18(A6) Set the search limit to 16 megabytes. FC241E bsr FC27EA Display the ROM-Wack register frame. FC2422 bsr FC2B94 Enter the ROM-Wack main loop. ; Entry point for command. ; Entry point to run a single instruction in trace mode. This does ; everything required to resume running as below, but with the trace ; mode bit set in the saved status register, so only a single ; instruction will be executed after the RTE (and then we come back ; in at the top). FC2426 move.l $84(A6),A0 Point to data on system stack. FC242A move.w 4(A0),$56(A0) Get the saved status register, set FC2430 or.w #$8000,$56(A0) the trace mode bit, and store it. FC2436 bra.s FC2452 ; Set up to continue running after exit from ROM-Wack. Note that ; to compensate for the different exception stack frame formats of ; bus error and regular exceptions, we don't even try to compensate ; for the format of the exception stack frame, just build one ; containing a simple status register and program counter right ; above the register dump. This allows the RTE instruction to ; conveniently resume running whatever called ROM-Wack, but ; some garbage may be left on the stack. ; Entry point for "go" command. ; This starts running wherever the current address is pointing. FC2438 move.l $84(A6),A0 Point to data on system stack. FC243C move.l $0C(A6),0(A0) Make PC the current address. ; Entry point for "^D" and "resume" commands. ; This continues running where it left off. FC2442 move.l $84(A6),A0 FC2446 move.w 4(A0),$56(A0) Get the saved status register. FC244C and.w #$7FFF,$56(A0) Clear the trace mode flag and put it on the stack. FC2452 move.w $EA(A6),DFF09A Restore serial port interrupt status. FC245A move.l 0(A0),$58(A0) Put the program counter on the stack. FC2460 move.l 6(A0),A1 Get the saved user stack pointer, FC2464 move A1,USP and restore it. FC2466 lea $16(A0),SP Point to the register dump. FC246A movem.l (SP)+,D0-D7/A0-A6 Restore all the other registers. FC246E addq.l #4,SP Pop the exception number. FC2470 rte Return from the exception. ; Subroutine to initialize ROM-Wack's data area. FC2472 move.l A6,A0 Point to data area. FC2474 move.w #$75,D0 FC2478 clr.w (A0)+ Clear 236 bytes. FC247A dbra D0,FC2478(PC) FC247E move.l #$FC3254,0(A6) Use primary key bindings. FC2486 move.l #$000010,$14(A6) Frame size = 16 bytes. FC248E move.w #$4E4F,$88(A6) Use "TRAP #15" for breakpoints. FC2494 rts FC2496 0000 Padding. ; A lot of the functions in ROM-Wack have C compatible entry points ; (which get the parameters from the stack), and most of them have ; C compatible return values (in D0). I guess this is to interface ; them to other functions, written in C, in the bigger versions of ; Wack. Likewise, the following are probably C interface functions, ; but they (and most of the C entry points) aren't used anywhere. ; "Peek" function for C. Takes address, returns 16-bit contents. FC2498 move.l 4(SP),A0 FC249C move.l (A0),D0 FC249E rts ; I have no idea why this is here twice. FC24A0 move.l 4(SP),A0 FC24A4 move.w (A0),D0 FC24A6 rts ; "Poke" function for C. Takes address and a word, and stores the ; word at the address given. FC24A8 movem.l 4(SP),A0/A1 FC24AE move.w A1,(A0) FC24B0 rts ; Entry point for "user" command. ; Takes all the data currently resident on the supervisor ; stack (exception stack frame, exception number, register dump, ; ROM-Wack data area, and any other stuff), and moves it onto the ; user stack. Then puts the CPU into user mode. ; In effect, this switches ROM-Wack from running as part of the ; exec kernel (in supervisor mode) to running as a plain, ordinary ; task, along with other tasks. The good side is that the system ; can now go and clean up (flush disk buffers, etc), while the ; user can go on playing with ROM-Wack. The bad side is that the ; task which did Debug() or trapped into ROM-Wack is stuck there ; forever. "go", and "resume" commands will no longer work. FC24B2 move.l $84(A6),A0 Point to data area on stack. FC24B6 btst #5,4(A0) Was CPU in supervisor mode? FC24BC bne.s FC24EC If not, exit. FC24BE move.l 6(A0),A1 Get the user stack pointer. FC24C2 lea -$5C(A1),A1 Reserve 92 bytes on user stack. FC24C6 move.l A1,$84(A6) Make this the new data area. FC24CA lea $5C(A1),A1 Point to top of new data area. FC24CE add.w #$5C,A0 Point to top of old data area. FC24D2 move.l A0,D1 Save the supervisor stack pointer. FC24D4 move.l A0,D0 FC24D6 sub.l SP,D0 FC24D8 bra.s FC24DC Copy exception stack frame, register FC24DA move.b -(A0),-(A1) dump, data area, and any other stuff FC24DC dbra D0,FC24DA(PC) to the user stack. FC24E0 move.l D1,SP Bump supervisor stack pointer up. FC24E2 move A1,USP Bump user stack pointer down. FC24E4 move.l $84(A6),A0 FC24E8 move 4(A0),SR Get the saved status register. FC24EC bsr FC2A72 Print a newline. FC24F0 rts ; String compare function. This checks if a command entered by ; the user, pointed to by A1, matches a command, pointed to by A0, ; from the command table. It returns zero if so, else it returns ; the character number at which the mismatch occurred. ; C style entry point. FC24F2 movem.l 4(SP),A0/A1 ; Assembler entry point. FC24F8 moveq #-1,D0 FC24FA move.b (A0)+,D1 Get a byte from reference string. FC24FC beq.s FC2508 End of string? FC24FE cmp.b (A1)+,D1 Compare to byte from second string. FC2500 dbne D0,FC24FA(PC) Loop while strings are equal. FC2504 neg.l D0 Compute number of equal characters. FC2506 bra.s FC250E Exit. FC2508 cmp.b (A1)+,D1 Check if other string ends also. FC250A bne.s FC250E FC250C moveq #0,D0 Return zero (strings match). FC250E rts ; Entry point for command (Redisplay frame). FC2510 move.b #1,$1E(A6) Request redisplay of current frame. FC2516 rts ; I don't know what this is for. It's not referenced anywhere. FC2518 move.l 8(A6),D0 FC251C move.l D0,-(SP) FC251E addq.l #4,SP FC2520 rts ; Entry point for ">", commands (Move forward a word). FC2522 addq.l #2,$0C(A6) Increment current address by 1 word. FC2526 move.b #1,$1E(A6) Request frame display. FC252C btst #1,$1F(A6) FC2532 beq.s FC2540 FC2534 bsr FC2A72 Print a newline. FC2538 bsr FC261A FC253C clr.b $1E(A6) FC2540 rts ; Entry point for "<", commands (Move back a word). FC2542 subq.l #2,$0C(A6) Decrement current address by 1 word. FC2546 move.b #1,$1E(A6) Request frame display. FC254C btst #1,$1F(A6) FC2552 beq.s FC2560 FC2554 bsr FC2A72 Print a newline. FC2558 bsr FC261A FC255C clr.b $1E(A6) FC2560 rts ; Entry point for "." command (move forward a frame). FC2562 move.l $14(A6),D0 Get frame size. FC2566 add.l D0,$0C(A6) Add to current address. FC256A move.b #1,$1E(A6) Request frame display. FC2570 rts ; Entry point for "," command (move back a frame). FC2572 move.l $14(A6),D0 Get frame size. FC2576 sub.l D0,$0C(A6) Subtract from current address. FC257A move.b #1,$1E(A6) Request frame display. FC2580 rts ; Entry point for "[" command. ; This follows a pointer at the current address. FC2582 move.l $26(A6),A1 Get indirection stack pointer. FC2586 move.l $0C(A6),A0 Get current location. FC258A move.l A0,(A1)+ Store in indirection stack. FC258C move.l A1,$26(A6) Put indirection stack pointer back. FC2590 moveq #-2,D0 Make the current location even. FC2592 and.l (A0),D0 Get the pointer. FC2594 move.l D0,$0C(A6) Put it in the current location. FC2598 move.b #1,$1E(A6) Request display of frame. FC259E rts ; Entry point for "]" command. ; This walks undoes a "[" command, good for walking back along ; singly linked lists or backing out of nested structure pointers. FC25A0 move.l $26(A6),A1 Get indirection stack pointer. FC25A4 move.l -(A1),$0C(A6) Get address from indirection stack. FC25A8 move.b #1,$1E(A6) Request frame display. FC25AE move.l A1,$26(A6) Update the indirection stack pointer. FC25B2 rts ; Entry point for "+" command. FC25B4 moveq #$2B,D0 Echo "+" on the user's terminal. FC25B6 bsr FC222E FC25BA bsr FC2BF0 Read a number from the keyboard. FC25BE tst.l D0 FC25C0 beq FC2A72 If none, print newline and exit. FC25C4 move.l 8(A6),D0 Get the number which was entered. FC25C8 add.l D0,$0C(A6) Add to current address. FC25CC move.b #1,$1E(A6) Request frame redisplay. FC25D2 rts ; Entry point for "-" command. FC25D4 moveq #$2D,D0 Echo "-" on the user's terminal. FC25D6 bsr FC222E FC25DA bsr FC2BF0 Read a number from the keyboard. FC25DE tst.l D0 FC25E0 beq FC2A72 If none, print newline and exit. FC25E4 move.l 8(A6),D0 Get the number which was entered. FC25E8 sub.l D0,$0C(A6) Subtract from the current address. FC25EC move.b #1,$1E(A6) Request frame redisplay. FC25F2 rts ; The following isn't referenced anywhere. Perhaps an outdated ; bit of code to set the current address to the last number entered. ; This is now unnecessary. FC25F4 move.l 8(A6),$0C(A6) FC25FA move.b #1,$1E(A6) FC2600 rts ; Entry point for ":" command (set frame size). FC2602 moveq #$3A,D0 Echo ":" on the terminal. FC2604 bsr FC222E FC2608 bsr FC2BF0 Get a number from the terminal. FC260C move.l 8(A6),$14(A6) Set the frame size. FC2612 move.b #1,$1E(A6) Request frame redisplay. FC2618 rts ; Routine to print a prompt for memory-modify commands. FC261A move.l $0C(A6),D0 Get the current address. FC261E bsr FC2780 Print it (6 digits). FC2622 tst.l $14(A6) Is the frame size zero? FC2626 beq.s FC2638 If frame size is not zero, then FC2628 move.l D0,A0 FC262A move.w (A0),D0 Get word at current address. FC262C bsr FC2788 Print it (4 digits). FC2630 moveq #$3D,D0 Print "=". FC2632 bsr FC222E FC2636 bra.s FC2640 Else FC2638 lea FC2668(PC),A0 Print "xxxx =" FC263C bsr FC2278 Endif FC2640 rts ; Entry point for "=" command (modify one word of memory). ; This is also used by the "alter" routine below. It returns 1 ; if a value was entered, and 0 if not. FC2642 bsr.s FC261A Print a prompt. FC2644 bsr FC2BF0 Get a number from the terminal. FC2648 tst.l D0 Did we get one? FC264A beq.s FC2658 FC264C move.l $0C(A6),A0 If so, update the word pointed FC2650 move.l 8(A6),D0 to by the current address with the FC2654 move.w D0,(A0) data which was entered, and return FC2656 moveq #1,D0 a non-zero value. FC2658 btst #1,$1F(A6) Are we in "alter" mode? FC265E bne.s FC2666 FC2660 move.b #1,$1E(A6) If not, request frame redisplay. FC2666 rts FC2668 "xxxx =", 00, 00 ; Entry point for "alter" command. FC2670 bset #1,$1F(A6) Set "alter mode" flag. FC2676 bsr FC2A72 Print a newline. FC267A bsr.s FC2642 Do an "=" command. FC267C tst.l D0 FC267E beq.s FC2686 If a value was entered, increase the FC2680 addq.l #2,$0C(A6) current location by 2, and loop back. FC2684 bra.s FC2676 FC2686 bclr #1,$1F(A6) Clear "alter mode" flag. FC268C bsr FC2A72 Print a newline. FC2690 rts ; I don't know what this is for. Perhaps a remnant from an old ; version of ROM-Wack, or something from a bigger version of Wack. ; It's not called from anywhere. FC2692 lea FC269C(PC),A0 Point to the string below. FC2696 bsr FC2278 Print it. FC269A rts FC269C LF, "not yet implemented", LF, 00 ; Entry point for "list" command. ; This will traverse a standard exec list, displaying information ; about each node. It should be called when the current address is ; either that of the list header, or of any node. FC26B2 move.l A2,-(SP) FC26B4 move.l $0C(A6),A2 Get the current address. FC26B8 tst.l 4(A2) List header ("Tail" field zero)? FC26BC bne.s FC26C0 FC26BE move.l (A2),A2 If yes, go to first node. FC26C0 move.l (A2),D0 See if now at end of list (or empty). FC26C2 beq.s FC26F4 If no more nodes, exit. FC26C4 move.l $0A(A2),D0 Get the node's name. FC26C8 bne.s FC26D0 If name pointer is null, replace FC26CA move.l #$FC271E,D0 it with a pointer to a zero. FC26D0 move.l D0,-(SP) Save name pointer on stack. FC26D2 moveq #0,D0 FC26D4 move.b 9(A2),D0 Get priority field. FC26D8 move.l D0,-(SP) Put it on the stack. FC26DA move.b 8(A2),D0 Get type field. FC26DE move.l D0,-(SP) Put it on the stack. FC26E0 pea (A2) Put node address to stack. FC26E2 move.l SP,A1 Point to data on stack. FC26E4 lea FC26FC(PC),A0 Point to format string below. FC26E8 bsr FC22D2 RawDoFmt() to serial port. FC26EC lea $14(SP),SP Pop data back off the stack. FC26F0 move.l (A2),A2 Move to next node. FC26F2 bra.s FC26C0 Loop until no more nodes. FC26F4 bsr FC2A72 Print a newline. FC26F8 move.l (SP)+,A2 FC26FA rts FC26FC LF, "%06lx type %-2ld pri %-4ld "%s"", 00, 00 ; Subroutine to display a "frame" of data from memory. On entry, ; the address of the frame is given in D0, and its size in D1. ; Data is displayed in lines of up to 8 words, and as an address, ; followed by hex words, followed by their ASCII character ; equivalents. FC2720 movem.l D0/D2/D3/A2/A3,-(SP) FC2724 link A5,#-$28 Reserve 40 bytes of stack space. FC2728 bsr FC2A72 Print a newline. FC272C move.l D0,A2 FC272E move.l D1,D2 Set number of bytes remaining. FC2730 beq.s FC2770 Just exit if frame size is zero. ; Outer loop: Display one line of the frame. FC2732 move.l A2,D0 FC2734 bsr.s FC2780 Print the address. FC2736 moveq #7,D3 Maximum 8 words per line. FC2738 lea -$20(A5),A3 Point to reserved stack space. ; Inner loop: Display one word of data. FC273C move.w (A2)+,D0 Get a word from memory. FC273E bsr.s FC2788 Print it. FC2740 move.l D0,-(SP) FC2742 lsr.w #8,D0 Get high 8 bits of current word. FC2744 bsr FC2ABC Convert to printable data. FC2748 move.w D0,(A3)+ Add to character string. FC274A move.l (SP)+,D0 FC274C bsr FC2ABC Do likewise for low 8 bits. FC2750 move.w D0,(A3)+ FC2752 subq.l #2,D2 Decrement number of bytes remaining. FC2754 ble.s FC2766 Exit if zero, FC2756 dbra D3,FC273C(PC) otherwise continue until line full. ; End of line reached. FC275A clr.w (A3)+ Mark end of character string. FC275C lea -$20(A5),A0 Point to beginning. FC2760 bsr FC2A86 Print the string and a newline. FC2764 bra.s FC2732 Go and do next line. ; End of frame reached. FC2766 clr.w (A3)+ Mark end of character string. FC2768 lea -$20(A5),A0 Point to beginning. FC276C bsr FC2A86 Print the string and a newline. FC2770 unlk A5 FC2772 movem.l (SP)+,D0/D2/D3/A2/A3 FC2776 rts ; Subroutine to display an 8-digit hex number. FC2778 movem.l D0/D1/A0/A1,-(SP) FC277C moveq #8,D1 8 digits. FC277E bra.s FC278E ; Subroutine to display a 6-digit hex number (address). FC2780 movem.l D0/D1/A0/A1,-(SP) FC2784 moveq #6,D1 6 digits. FC2786 bra.s FC278E ; Subroutine to display a 4-digit hex number. FC2788 movem.l D0/D1/A0/A1,-(SP) FC278C moveq #4,D1 4 digits. FC278E bsr FC2294 Go print the number. FC2792 movem.l (SP)+,D0/D1/A0/A1 FC2796 rts ; Subroutine to print the "DR:", "AR:", and "SF:" portions of ; the ROM-Wack register frame. FC2798 movem.l D2/A2,-(SP) FC279C move.l A0,A2 FC279E moveq #7,D2 7 Data registers. FC27A0 lea FC2864(PC),A0 Point to "\nDR: " string. FC27A4 bsr.s FC27D8 Display data registers. FC27A6 moveq #6,D2 6 Address registers. FC27A8 lea FC286A(PC),A0 Point to "\nAR: " string. FC27AC bsr.s FC27D8 Display address registers. FC27AE addq.l #4,A2 Skip exception number on stack. FC27B0 btst #5,(A2) Supervisor mode? FC27B4 bne.s FC27BC FC27B6 sub.w #$50,A2 If not, get saved USP. FC27BA move.l (A2),A2 FC27BC lea FC2870(PC),A0 Point to "\nSF: " string. FC27C0 bsr FC2278 Print it. FC27C4 moveq #$0E,D2 FC27C6 move.w (A2)+,D0 Display 14 words of stack data. FC27C8 bsr.s FC2788 FC27CA dbra D2,FC27C6(PC) FC27CE bsr FC2A72 Print a newline. FC27D2 movem.l (SP)+,D2/A2 FC27D6 rts ; Subroutine to print a string pointed to by A0, followed by (D2) ; longwords from memory pointed to by A2. FC27D8 bsr FC2278 Print the string. FC27DC move.l (A2)+,D0 FC27DE bsr.s FC2778 Loop and print all the data. FC27E0 dbra D2,FC27DC(PC) FC27E4 rts ; Subroutine to print the first ("PC: ...") line of the register ; frame, followed by the rest of the register frame via the routine ; above. Note, we just give RawDoFmt() a format string describing ; the data structure on the supervisor stack ; Also entry point for "regs" command. FC27E6 move.l $84(A6),A1 Get pointer to stack-resident data. FC27EA move.l A1,-(SP) FC27EC lea FC27FC(PC),A0 Point to format string. FC27F0 bsr FC22D2 Format the data. FC27F4 move.l (SP)+,A1 FC27F6 lea $16(A1),A0 Point to the register dump area. FC27FA bra.s FC2798 Print it. ; Text strings used to display register frames. The second one ; isn't used anywhere. FC27FC LF, "PC: %06lx SR: %04x USP: %06lx SSP: %06lx XCPT: " FC2830 "%04lx TASK: %06lx", 00 FC2843 LF, "PC: %06lx SR: %04x USP: %06lx", 00 FC2864 LF, "DR: ", 00 FC286A LF, "AR: ", 00 FC2870 LF, "SF: ", 00 ; Memory fill routine. Fills (D1) words, starting at (D0), with ; the value in D2. Not used anywhere. FC2876 move.l A2,-(SP) FC2878 move.l D0,A2 FC287A bra.s FC287E FC287C move.w D2,(A2)+ FC287E dbra D1,FC287C(PC) FC2882 move.l (SP)+,A2 FC2884 rts ; Subroutine to find a breakpoint in the breakpoint table, given ; its address. If successful, returns address of breakpoint table ; entry, if not, returns zero. FC2886 bsr FC2A72 Print a newline. FC288A lea $8A(A6),A0 Point to breakpoint table. FC288E moveq #$0F,D1 FC2890 cmp.l (A0),A1 Scan breakpoint table for a FC2892 beq.s FC289E breakpoint address matching A1. FC2894 addq.l #6,A0 FC2896 dbra D1,FC2890(PC) FC289A moveq #0,D0 Not found, so return zero. FC289C rts FC289E move.l A0,D0 Return address of table entry. FC28A0 rts ; Entry point for "clear" command. ; Deactivate the breakpoint at the current program address, ; if there is one. FC28A2 move.l $0C(A6),A1 Get current address. FC28A6 bsr.s FC2886 See if it is a breakpoint address. FC28A8 beq.s FC28B0 FC28AA clr.l (A0) If so, deactivate it and write the FC28AC move.w 4(A0),(A1) original instruction back. FC28B0 rts ; Entry point for "reset" command. ; Deactivates all breakpoints. FC28B2 lea $8A(A6),A1 Point to ROM-Wack's breakpoint table. FC28B6 moveq #$0F,D1 Size of breakpoint table - 1. FC28B8 move.l (A1),D0 Get breakpoint address. FC28BA beq.s FC28C4 If breakpoint in use then FC28BC move.l D0,A0 FC28BE clr.l (A1) Clear breakpoint address. FC28C0 move.w 4(A1),(A0) Fix instruction at breakpoint. Endif FC28C4 addq.l #6,A1 Go to next table entry. FC28C6 dbra D1,FC28B8(PC) Loop until whole table done. FC28CA bsr FC2A72 Print a newline. FC28CE rts ; Entry point for "set" command. ; Activates a breakpoint at the current address. FC28D0 move.l $0C(A6),A1 Get current address. FC28D4 bsr.s FC2886 See if it is a breakpoint. FC28D6 bne.s FC28FC If so, do nothing. FC28D8 lea $8A(A6),A0 FC28DC moveq #$0F,D1 Scan the breakpoint table for an FC28DE tst.l (A0) unused entry. FC28E0 beq.s FC28F2 FC28E2 addq.l #6,A0 FC28E4 dbra D1,FC28DE(PC) ; No unused breakpoint table entry found. FC28E8 lea FC28FE(PC),A0 Point at "too many" string. FC28EC bsr FC2278 Print it. FC28F0 bra.s FC28FC Return. ; Unused entry in the breakpoint table found. Activate a breakpoint. FC28F2 move.w (A1),4(A0) Save instruction at breakpoint. FC28F6 move.w $88(A6),(A1) Replace with TRAP #15. FC28FA move.l A1,(A0) Save the breakpoint address. FC28FC rts FC28FE LF, "too many", LF, 00, 00 ; Entry point for "show" command. ; Lists all active breakpoints. FC290A lea $8A(A6),A0 Point to breakpoint table. FC290E moveq #$0F,D1 Loop for 16 entries. FC2910 move.l (A0),D0 Get current breakpoint address. FC2912 beq.s FC291C Skip if zero. FC2914 bsr FC2A72 Print a newline. FC2918 bsr FC2780 Print the breakpoint address. FC291C addq.l #6,A0 Go to next table entry. FC291E dbra D1,FC2910(PC) Loop until done. FC2922 bsr FC2A72 Print a newline. FC2926 rts FC2928 rts Garbage. ; Subroutine to get a character and echo it to the user. FC292A bsr FC2222 Get a character. FC292E move.l D0,-(SP) FC2930 bsr FC222E Echo it back. FC2934 move.l (SP)+,D0 FC2936 rts ; Entry point for "!" command (Modify a register). FC2938 movem.l D2/A2,-(SP) FC293C moveq #$21,D0 Print "!". FC293E bsr FC222E FC2942 bsr.s FC292A Get a character. FC2944 bsr FC2D48 Convert to upper case. FC2948 move.l $84(A6),A1 Get pointer to stack-resident data. FC294C lea $16(A1),A0 Point to data register dump area. FC2950 moveq #7,D2 Maximum data register # = 7. FC2952 cmp.b #'D',D0 [D]ata register? FC2956 beq.s FC2970 FC2958 lea $20(A0),A0 Point to address register dump. FC295C moveq #6,D2 Maximum address register # = 6. FC295E cmp.b #'A',D0 [A]ddress register? FC2962 beq.s FC2970 FC2964 lea 6(A1),A2 Point to user stack pointer. FC2968 cmp.b #'U',D0 [U]SP? FC296C beq.s FC298C If so, go change it. FC296E bra.s FC29A8 Otherwise, exit. ; Enter here with A0 pointing to a dump area containing sequential ; images of the address or data registers, and D2 containing the ; maximum register number. FC2970 bsr.s FC292A Get a character. FC2972 cmp.w #8,D0 Backspace? FC2976 beq.s FC29A8 If so, exit. FC2978 bsr FC2AAC Is it a digit? FC297C bne.s FC29A8 If not, exit. FC297E sub.w #$30,D0 Convert to number. FC2982 cmp.b D0,D2 Greater than maximum? FC2984 blt.s FC29A8 If so, exit. FC2986 lsl.w #2,D0 Compute offset to given register. FC2988 lea 0(A0,D0.w),A2 Compute address of register. ; Enter here with A2 pointing to a longword containing the image ; of the register to modify. FC298C move.l (A2),D0 Get the current value. FC298E bsr FC2A62 Print a space. FC2992 bsr FC2778 Display value as 8 hex digits. FC2996 moveq #$3D,D0 Print "=" FC2998 bsr FC222E FC299C bsr FC2BF0 Get the new value from the user. FC29A0 tst.b D0 Was a value entered? FC29A2 beq.s FC29A8 If not, exit. FC29A4 move.l 8(A6),(A2) Update the register. FC29A8 bsr FC2A72 Print a newline. FC29AC movem.l (SP)+,D2/A2 FC29B0 rts ; Entry point for "^" and "limit" commands. ; This copies the current address to the "limit" address, i.e. the ; address to stop searching or filling memory at. FC29B2 move.l $0C(A6),$18(A6) Copy current address to limit. FC29B8 move.b #1,$1E(A6) Request frame redisplay. FC29BE rts ; Entry point for "find" command. FC29C0 movem.l A2/A3,-(SP) FC29C4 bsr.s FC2A04 Get the search pattern. FC29C6 beq.s FC29D4 Exit if none entered. FC29C8 bsr.s FC29E0 Do the searching. FC29CA beq.s FC29D4 Exit if not found. FC29CC bclr #0,D0 Round result address down to even. FC29D0 move.l D0,$0C(A6) Store it in current address. FC29D4 move.b #1,$1E(A6) Request frame redisplay. FC29DA movem.l (SP)+,A2/A3 FC29DE rts ; Search routine for the "find" command. FC29E0 move.l A4,-(SP) FC29E2 lea -2(A0),A4 Start searching at start address - 2. FC29E6 move.l D0,D1 Set the number of bytes to match. FC29E8 move.l A3,A1 Set the search pattern address. FC29EA addq.l #1,A4 Go to next address. FC29EC move.l A4,A0 FC29EE cmp.l A0,A2 See if limit address reached. FC29F0 ble.s FC29FE If so, return false. FC29F2 cmpm.b (A1)+,(A0)+ Compare one byte. FC29F4 bne.s FC29E6 Go to next address if mismatch. FC29F6 subq.w #1,D1 Decrement byte counter. FC29F8 bgt.s FC29EE Loop until all matched. FC29FA move.l A4,D0 Found: return the address where. FC29FC bra.s FC2A00 FC29FE moveq #0,D0 Return false. FC2A00 move.l (SP)+,A4 FC2A02 rts ; Search/fill pattern input routine. Prompts for a pattern, ; accepts it, and returns the following: ; D0: Number of bytes in search pattern. ; D1: True if pattern entered, false if aborted. ; A0: Lower bound for search. ; A2: Upper bound for search. ; A3: Address of search pattern. FC2A04 lea FC2A2C(PC),A0 Point to "pattern? " string. FC2A08 bsr FC2278 Print it. FC2A0C bsr FC2BF0 Get a number from the terminal. FC2A10 tst.w D0 Did we get one? FC2A12 beq.s FC2A2A If not, return false. FC2A14 addq.w #1,D0 FC2A16 lsr.w #1,D0 Compute 4-(d+1)/2, where d is the FC2A18 moveq #4,D1 number of digits entered. FC2A1A sub.w D0,D1 FC2A1C lea 8(A6,D1.w),A3 Get the number entered. FC2A20 move.l $0C(A6),A0 Get the current address, FC2A24 move.l $18(A6),A2 and the limit address. FC2A28 moveq #1,D1 Return true. FC2A2A rts FC2A2C " pattern? ", 00, 00 ; Entry point for "fill" command. FC2A38 movem.l A2/A3,-(SP) FC2A3C bsr.s FC2A04 Get the fill pattern. FC2A3E beq.s FC2A42 FC2A40 bsr.s FC2A4E If one entered, go do the fill. FC2A42 move.b #1,$1E(A6) Request frame redisplay. FC2A48 movem.l (SP)+,A2/A3 FC2A4C rts ; Fill routine for the "fill" command. FC2A4E subq.l #1,D0 Adjust number of bytes for "dbra". FC2A50 move.l D0,D1 Initialize loop counter. FC2A52 move.l A3,A1 Initialize pattern address. FC2A54 cmp.l A0,A2 Upper limit reached? FC2A56 ble.s FC2A60 Exit if so. FC2A58 move.b (A1)+,(A0)+ Copy one byte from the fill pattern. FC2A5A dbra D1,FC2A54(PC) Loop until pattern done. FC2A5E bra.s FC2A50 Loop back and do pattern again. FC2A60 rts ; Subroutine to print a single space. FC2A62 movem.l D0/D1/A0/A1,-(SP) FC2A66 moveq #$20,D0 Character code for a space. FC2A68 bsr FC222E RawPutChar() FC2A6C movem.l (SP)+,D0/D1/A0/A1 FC2A70 rts ; Subroutine to print a single newline. FC2A72 movem.l D0/D1/A0/A1,-(SP) FC2A76 lea FC2A84(PC),A0 Point to string below. FC2A7A bsr FC2278 Print it. FC2A7E movem.l (SP)+,D0/D1/A0/A1 FC2A82 rts FC2A84 LF, 00 ; Subroutine to print string at address pointed to by A0, followed ; by a newline. FC2A86 movem.l D0/D1/A0/A1,-(SP) FC2A8A bsr FC2278 Print the string. FC2A8E bsr.s FC2A72 Print a newline. FC2A90 movem.l (SP)+,D0/D1/A0/A1 FC2A94 rts ; I don't know what this is for. It's not referenced anywhere. FC2A96 moveq #$0D,D0 FC2A98 rts ; Subroutine to get a character. Returns with the zero flag clear ; if a character was received, set otherwise. FC2A9A movem.l D0/D1/A0/A1,-(SP) FC2A9E bsr FC2202 FC2AA2 cmp.w #$FFFF,D0 FC2AA6 movem.l (SP)+,D0/D1/A0/A1 FC2AAA rts ; Isdigit() type of function. Enter with a character in D0, returns ; with the zero flag set if the character is a numeric digit. FC2AAC cmp.b #'0',D0 FC2AB0 blt.s FC2ABA FC2AB2 cmp.b #'9',D0 FC2AB6 bgt.s FC2ABA FC2AB8 cmp.b D0,D0 FC2ABA rts ; Subroutine to convert an 8-bit code in D0 to a 2 character ; printable ASCII version. ; Codes 0 and 128-255 return "..", control codes are shown as "^A" ; to "^\", other characters are shown as a space, then the actual ; character. FC2ABC move.l D2,-(SP) FC2ABE move.w #$2E2E,D2 Move ".." into D2. FC2AC2 tst.b D0 Is the code zero? FC2AC4 beq.s FC2AE2 If so, return ".." and exit. FC2AC6 btst #7,D0 Is the high bit set? FC2ACA bne.s FC2AE2 If so, return ".." and exit. FC2ACC move.w #$2000,D2 Move space and null into D2. FC2AD0 move.b D0,D1 FC2AD2 and.b #$E0,D1 If the character is a control code, FC2AD6 bne.s FC2AE0 FC2AD8 move.w #$5E00,D2 Move "^" and null into D2. FC2ADC or.b #$40,D0 Convert to printable character. FC2AE0 move.b D0,D2 Put it into D2. Endif FC2AE2 move.l D2,D0 Return D2. FC2AE4 move.l (SP)+,D2 FC2AE6 rts ; ROM-Wack command execution function. Calls the command function ; given in A0, and on return, displays the current "frame" if ; requested by the command function. FC2AE8 clr.b $1E(A6) FC2AEC move.l 4(SP),A0 Get the command function address. FC2AF0 jsr (A0) Execute the function. FC2AF2 tst.b $1E(A6) Need to display frame? FC2AF6 beq.s FC2B04 Exit if not. FC2AF8 move.l $0C(A6),D0 Get current address. FC2AFC move.l $14(A6),D1 Get frame size. FC2B00 bsr FC2720 Display the frame. FC2B04 rts ; Entry point for "?" command (Display multi-character commands). FC2B06 move.l A2,-(SP) FC2B08 move.l #$FC33A6,A2 Point to ROM-Wack command table. FC2B0E move.b (A2)+,D0 Get a character. FC2B10 beq.s FC2B18 FC2B12 bsr FC222E If not zero, print it, and loop FC2B16 bra.s FC2B0E back to do the next one. FC2B18 bsr FC2A62 Print a space. FC2B1C tst.b (A2) Another zero? FC2B1E bne.s FC2B0E If not, loop back & print next cmd. FC2B20 bsr FC2A72 Print a newline. FC2B24 move.l (SP)+,A2 FC2B26 rts ; ROM-Wack command dispatch table scanner. ; Enter with a character code in D0. This routine runs through the ; command table, and returns either the address of the command table ; entry matching the character, or zero. ; Each command table entry either corresponds to exactly one ; character, or to a range of characters. This may sound confusing, ; but I've commented the command table itself, so you can just look ; there and it will be perfectly obvious. FC2B28 move.l D0,D1 FC2B2A move.l 0(A6),A0 Point to command table. FC2B2E bra.s FC2B3C FC2B30 move.l (A0),D0 Get link to next table entry. FC2B32 and.l #$FFFFFF,D0 Strip off high 8 bits. FC2B38 beq.s FC2B4C Exit if no next entry. FC2B3A move.l D0,A0 Point ot next entry. FC2B3C cmp.b 4(A0),D1 See if command matches table entry. FC2B40 beq.s FC2B4A Exit if it does. FC2B42 blt.s FC2B30 Go to next entry if smaller. FC2B44 cmp.b 5(A0),D1 Check if in range. FC2B48 bgt.s FC2B30 Go to next entry if not. FC2B4A move.l A0,D0 Return table entry address. FC2B4C rts ; ROM-Wack command dispatcher. Given a command character, looks it ; up in the command dispatch table and executes the command if found. ; C style entry point. FC2B4E move.l 4(SP),D0 ; Assembler entry point. FC2B52 bsr.s FC2B28 Look command up in command table. FC2B54 tst.l D0 Found it? FC2B56 beq.s FC2B64 Exit if not. FC2B58 move.l D0,A0 FC2B5A move.l 6(A0),-(SP) Get execution address from table and store it on the stack. FC2B5E bsr FC2AE8 Execute the function. FC2B62 addq.l #4,SP Pop address back off the table. FC2B64 rts ; Multi-character command lookup function. ; This takes a pointer to a command string in A0, and looks it up ; in the table of multi-character commands. It returns the address ; of the table entry corresponding to the command, or zero if the ; command was not found. ; C style entry point. FC2B66 move.l 4(SP),A0 ; Assembler entry point. FC2B6A movem.l A2/A3,-(SP) FC2B6E move.l A0,A2 FC2B70 lea FC33F4,A3 Point at command dispatch table. FC2B76 bra.s FC2B7E FC2B78 move.l (A3),D0 Get pointer to next table entry. FC2B7A beq.s FC2B8E Exit if null (end of table). FC2B7C move.l D0,A3 FC2B7E move.l 4(A3),A0 Get pointer to string. FC2B82 move.l A2,A1 Point to string to match. FC2B84 bsr FC24F8 Compare them. FC2B88 tst.l D0 Got a match? FC2B8A bne.s FC2B78 Keep looking if not. FC2B8C move.l A3,D0 Return table address. FC2B8E movem.l (SP)+,A2/A3 FC2B92 rts ; ROM-Wack main loop: Gets a character from the user, then ; interprets it, then gets next characer, etc. FC2B94 bsr FC2222 Get a character from the user. FC2B98 move.b D0,$82(A6) Store it. FC2B9C bsr.s FC2B52 Process it. FC2B9E bra.s FC2B94 Go get next character. ; Entry point for letters, numbers and underline characters typed ; at the ROM-Wack command level. This function collects them in ; a buffer. FC2BA0 lea FC3334,A0 Address of secondary key bindings. FC2BA6 cmp.l 0(A6),A0 Already using them? FC2BAA beq.s FC2BBE ; This is the first character of a multi character command, so ; clear the buffer and point to the other set of key bindings. FC2BAC clr.w $1C(A6) Zero characters in buffer so far. FC2BB0 move.l 0(A6),4(A6) Save address of primary key bindings. FC2BB6 move.l #$FC3334,0(A6) Point at secondary key bindings. FC2BBE cmp.b #' ',$82(A6) Was the key a space? FC2BC4 beq.s FC2BEA If so, ignore it (kludge, see below). FC2BC6 move.w $1C(A6),D0 Get number of chars in buffer FC2BCA cmp.w #$32,D0 50 characters already? FC2BCE bge.s FC2BEA If equal or more, ignore this one. FC2BD0 move.b $82(A6),D0 Get command character. FC2BD4 bsr FC222E Echo it to the user. FC2BD8 lea $50(A6),A0 Point to buffer. FC2BDC move.w $1C(A6),D0 Get offset into buffer. FC2BE0 move.b $82(A6),0(A0,D0.w) Store character in buffer. FC2BE6 addq.w #1,$1C(A6) Increment buffer count. FC2BEA clr.w $20(A6) There is unprocessed data in the FC2BEE rts buffer, so set the flag. ; Entry point to get a number from the user. FC2BF0 move.b #' ',$82(A6) Start using secondary key bindings. FC2BF6 bsr.s FC2BA0 FC2BF8 move.w #1,$24(A6) Indicate that input is being gathered for a specific function. ; Loop to read the digits. We stay in this loop, using the ; secondary (input gathering) key bindings until some command ; function switches us back to the primary ones. That means ; the user either canceled the line, or pressed RETURN. FC2BFE cmp.l #$FC3334,0(A6) Using secondary key bindings now? FC2C06 bne.s FC2C16 Exit loop if not. FC2C08 bsr FC2222 Get a key from the user. FC2C0C move.b D0,$82(A6) Store it in "last key typed". FC2C10 bsr FC2B52 Dispatch it as a command character. FC2C14 bra.s FC2BFE Loop. ; The input line has been processed. Either it was a command ; (and was executed), or it was a number, or it was an error. FC2C16 clr.w $24(A6) Clear "parameter input" flag. FC2C1A moveq #0,D0 FC2C1C move.b $22(A6),D0 Get number of digits. FC2C20 tst.w $20(A6) If no useful data in buffer (line FC2C24 beq.s FC2C28 canceled, command already executed, FC2C26 moveq #0,D0 bad symbol...), return zero digits. FC2C28 rts ; Entry point for while using the secondary key bindings. FC2C2A rts ; Entry point for CTRL-U and CTRL-X. Point back to the original ; set of key bindings, and set the buffer to empty. FC2C2C move.w #$FFFF,$1C(A6) -1 characters in buffer. FC2C32 move.l 4(A6),0(A6) Restore top-level key bindings. FC2C38 bsr FC2A72 Print a linefeed. FC2C3C move.w #1,$20(A6) Buffer contains no useful data. FC2C42 rts ; Entry point for . This deletes one charaacter from ; the input buffer. FC2C44 tst.w $1C(A6) Any characters in the buffer? FC2C48 ble.s FC2C2C If none, cancel input. FC2C4A lea $50(A6),A0 Point to buffer. FC2C4E move.w $1C(A6),D0 Get buffer offset. FC2C52 clr.b 0(A0,D0.w) Clear last character in buffer. FC2C56 subq.w #1,$1C(A6) Decrement buffer count. FC2C5A lea FC2C6A(PC),A0 Point to string below. FC2C5E bsr FC2278 Print it. FC2C62 tst.w $1C(A6) Is buffer now empty? FC2C66 ble.s FC2C2C If so, cancel input. FC2C68 rts ; String used to erase one character from the user's terminal. FC2C6A 08, " ", 08, 00 ; Entry point for . FC2C6E move.l 4(A6),0(A6) Restore previous key bindings. FC2C74 lea $50(A6),A0 Point to input buffer. FC2C78 move.w $1C(A6),D0 Get number of characters in it. FC2C7C bgt.s FC2C88 FC2C7E move.w #1,$20(A6) Indicate that no data is in the buffer waiting for processing. FC2C84 moveq #0,D0 FC2C86 rts ; There was data in the buffer, now interpret it. FC2C88 clr.b 0(A0,D0.w) Zero-terminate the buffer. FC2C8C lea $50(A6),A0 Point to it. FC2C90 bsr FC2B6A Look command up in table. FC2C94 tst.l D0 Branch if not found. FC2C96 beq.s FC2CB0 FC2C98 move.w #1,$20(A6) Indicate that buffer was processed. FC2C9E move.l D0,A0 Get the command table offset. FC2CA0 move.l $0A(A0),-(SP) Get execution address from table. FC2CA4 bsr FC2AE8 Execute the command. FC2CA8 clr.b $1E(A6) Clear frame redisplay flag. FC2CAC addq.l #4,SP Pop execution address of stack. FC2CAE rts ; Continue here if the buffer contained a string not found ; in the command table. For a full Wack, this means it would ; either be a number, or a symbol. For ROM-Wack, it's either ; a number or an error. FC2CB0 lea $50(A6),A0 Point to the string in the buffer. FC2CB4 lea 8(A6),A1 Point to input number location. FC2CB8 bsr FC2CFC Interpret input buffer as a number. FC2CBC move.b D0,$22(A6) Store number of digits. FC2CC0 bne.s FC2CD2 FC2CC2 move.w #1,$20(A6) If 0 digits (bad hex number), print FC2CC8 lea FC2CEA(PC),A0 "unknown symbol", indicate that no FC2CCC bsr FC2278 data is waiting in the buffer, and FC2CD0 rts exit. ; Continue here if number of digits was non-zero. If the number ; wasn't being gathered as a parameter to another command, make it ; the current location. FC2CD2 tst.w $24(A6) Parameter being gathered? FC2CD6 bne.s FC2CE8 Exit if so. FC2CD8 moveq #-2,D0 Round number down to even. FC2CDA and.l 8(A6),D0 FC2CDE move.l D0,$0C(A6) Set the current location to it. FC2CE2 bset #0,$1E(A6) Request (re)display of frame. FC2CE8 rts FC2CEA LF, "unknown symbol", LF, 00, 00 ; Hex number interpreting routine. FC2CFC move.l D2,-(SP) FC2CFE moveq #0,D1 Start result at zero. FC2D00 moveq #-1,D2 Start with "-1 digits". FC2D02 move.l D1,D0 FC2D04 bra.s FC2D0E Jump into the loop. FC2D06 addq.l #5,D0 Entry point for hex digits: Add 10. FC2D08 addq.l #5,D0 FC2D0A lsl.l #4,D1 Shift previous number left by 4 bits. FC2D0C add.l D0,D1 Add in new digit. FC2D0E addq.l #1,D2 Increment digit counter. FC2D10 move.b (A0)+,D0 Get a digit from the input string. FC2D12 beq.s FC2D3A Exit if end of string reached. FC2D14 sub.b #'0',D0 Subtract '0'. FC2D18 blt.s FC2D38 Exit if result less than zero. FC2D1A cmp.b #$0A,D0 Greater than 9? FC2D1E blt.s FC2D0A Branch if not. FC2D20 sub.b #$11,D0 Subtract 17. FC2D24 blt.s FC2D38 Exit if result less than zero. FC2D26 cmp.b #6,D0 Branch if less than 7. FC2D2A blt.s FC2D06 FC2D2C sub.b #$20,D0 Subtract ('a' - 'A'). FC2D30 blt.s FC2D38 Branch if less than zero. FC2D32 cmp.b #6,D0 FC2D36 blt.s FC2D06 Branch if less than 7. ; If we branch here, the number entered contained an invalid ; hexadecimal digit. FC2D38 moveq #0,D2 Return "0 digits". ; Branch here if end of string reached with no invalid digits. FC2D3A move.l D1,(A1) Store result where indicated. FC2D3C move.l D2,D0 Return number of digits. FC2D3E move.l (SP)+,D2 FC2D40 rts ; Some sort of format string. Not used anywhere. FC2D42 " %lx ", 00 ; Toupper() type of function. Converts character in D0 to upper ; case if necessary. FC2D48 cmp.b #'a',D0 Less than 'a'? FC2D4C blt.s FC2D58 FC2D4E cmp.b #'z',D0 Greater than 'z'? FC2D52 bgt.s FC2D58 FC2D54 sub.b #$20,D0 If neither, convert to upper case. FC2D58 rts FC2D5A 0000 Padding. --------------------------------------------------------------------------- result = Procure( semaphore, bidMessage ) D0 A0 A1 --------------------------------------------------------------------------- ; A Procure/Vacate semaphore is a message port structure plus a ; counter. A task can "lock" the semaphore, by calling Procure(). ; Further attempts to lock the semaphore won't succeed until the ; original locker unlocks the semaphore by Vacate(). ; A sm_Bids value of -1 indicates that the semaphore is free, zero ; indicates it's locked and no one is waiting, 1 means one task is ; waiting, etc. ; Whenever Procure() is called, a pointer to a message must be ; given. This message is enqueued on the semaphore's port if the ; semaphore is not currently available, and returned when the ; caller's turn comes up to get the lock. If the semaphore was ; available (sm_Bids = -1), the message is not used. FC2D5C addq.w #1,$22(A0) Increment the sm_Bids field. FC2D60 bne.s FC2D6A Check if the semaphore was free. FC2D62 move.l A1,$10(A0) If it was, store pointer to the current locker's message FC2D66 moveq #1,D0 and return TRUE. FC2D68 rts FC2D6A jsr -$016E(A6) If it wasn't, enqueue the message FC2D6E moveq #0,D0 on the semaphore's port and return FC2D70 bra.s FC2D68 FALSE. --------------------------------------------------------------------------- Vacate( semaphore ) A0 --------------------------------------------------------------------------- ; A task which has successfully obtained a semaphore via Procure() ; calls this to release it again. The sm_Bids field is decremented. ; If it was zero and ends up at -1, nobody else was waiting to use ; the semaphore. If it ends up positive, someone else is waiting ; and we must send his bid message back to let him know he has it ; now. The first message enqueued on the semaphore's port is the ; task which has waited longest and gets it. FC2D72 clr.l $10(A0) Clear pointer to locker's message. FC2D76 subq.w #1,$22(A0) Decrement sm_Bids field. FC2D7A bge.s FC2D7E Return if it is now -1. FC2D7C rts FC2D7E move.l A0,-(SP) Save semaphore pointer. FC2D80 jsr -$0174(A6) Dequeue the oldest bid message. FC2D84 move.l (SP)+,A0 Restore semaphore pointer. FC2D86 move.l D0,$10(A0) Store pointer to the message. FC2D8A beq.s FC2D7C Exit if no message (error). FC2D8C move.l D0,A1 FC2D8E jsr -$017A(A6) ReplyMsg() to inform the waiting FC2D92 bra.s FC2D7C task, then exit. --------------------------------------------------------------------------- InitSemaphore( signalSemaphore ) A0 --------------------------------------------------------------------------- FC2D94 lea $10(A0),A1 Point to the waiting task list. FC2D98 move.l A1,(A1) Initialize it to empty. FC2D9A addq.l #4,(A1) FC2D9C clr.l 4(A1) FC2DA0 move.l A1,8(A1) FC2DA4 clr.l $28(A0) Clear the ss_Owner field to null. FC2DA8 clr.w $0E(A0) Clear the ss_NestCount to zero. FC2DAC move.w #$FFFF,$2C(A0) Set the ss_QueueCount to -1. FC2DB2 rts --------------------------------------------------------------------------- ObtainSemaphore( signalSemaphore ) A0 --------------------------------------------------------------------------- FC2DB4 addq.b #1,$0127(A6) Forbid() FC2DB8 addq.w #1,$2C(A0) Increment the ss_QueueCount. FC2DBC bne.s FC2DC6 ; If the ss_Queuecount is now 0, then the semaphore was free and ; we got it. Set the pointer to the owning task, set the nesting ; level to 1, and exit. FC2DBE move.l $0114(A6),$28(A0) Store pointer to owning task. FC2DC4 bra.s FC2DFA ; The ss_Queuecount was not -1, so the semaphore was already owned ; by someone. Check if it is the calling task. FC2DC6 movem.l D0/D1/A0/A1,-(SP) FC2DCA move.l $0114(A6),A1 Get current task pointer. FC2DCE cmp.l $28(A0),A1 Do we own the semaphore already? FC2DD2 beq.s FC2DF6 If so, increment nest count and exit. ; Another task owns the semaphore at the moment, so we must block. ; Since all non-running tasks must be on the TaskWait queue, we ; can't just enqueue the task on the semaphore. Instead, we build ; a temporary node on the stack, and enqueue that. Then we clear ; signal #2, and wait for someone to set it, which will occur when ; the current owner of the semaphore releases it. When we wake up, ; we deallocate the temporary node, and return to the user. FC2DD4 lea -$0C(SP),SP Reserve 12 bytes of stack space. FC2DD8 move.l A1,8(SP) Store pointer to this task. FC2DDC bclr #4,$1D(A1) Clear signal #2. FC2DE2 lea $10(A0),A0 Point to waiting task list. FC2DE6 move.l SP,A1 FC2DE8 bsr FC15E8 Enqueue the temporary list node. FC2DEC moveq #$10,D0 FC2DEE jsr -$013E(A6) Wait for signal #2. FC2DF2 lea $0C(SP),SP Release the reserved stack space. FC2DF6 movem.l (SP)+,D0/D1/A0/A1 FC2DFA addq.w #1,$0E(A0) Increment the nesting count. FC2DFE jsr -$8A(A6) Permit() FC2E02 rts --------------------------------------------------------------------------- ReleaseSemaphore( signalSemaphore ) A0 --------------------------------------------------------------------------- FC2E04 subq.w #1,$0E(A0) Decrement the nesting count. FC2E08 beq.s FC2E12 If zero, release the semaphore. FC2E0A bmi.s FC2E50 If it went negative, guru city! FC2E0C subq.w #1,$2C(A0) Otherwise, just decrement the FC2E10 bra.s FC2E4E ss_QueueCount and exit. ; Continue here when the nesting count went to zero, and we ; therefore don't want the semaphore any more. FC2E12 addq.b #1,$0127(A6) Forbid() FC2E16 subq.w #1,$2C(A0) Decrement the ss_QueueCount. FC2E1A blt.s FC2E46 If now -1, nobody was waiting. ; The ss_Queuecount is still positive, so someone is blocked on ; the semaphore and waiting to be awakened. The first (oldest) ; entry on the semaphore's queue gets it. FC2E1C movem.l D0/D1/A1,-(SP) FC2E20 move.l A0,D1 Save semaphore pointer. FC2E22 lea $10(A0),A0 Point to semaphore's queue. FC2E26 bsr FC160E RemHead() FC2E2A tst.l D0 If the queue was empty, guru city! FC2E2C beq.s FC2E50 ; We have a pointer (in D0) to a node which identifies the ; waiting process (the temporary one allocated on that process's ; stack). FC2E2E move.l D1,A0 FC2E30 move.l D0,A1 FC2E32 move.l 8(A1),A1 Get pointer to waiting task. FC2E36 move.l A1,$28(A0) Make this task the ss_Owner. FC2E3A moveq #$10,D0 FC2E3C jsr -$0144(A6) Set waiting task's signal #2. FC2E40 movem.l (SP)+,D0/D1/A1 FC2E44 bra.s FC2E4A Exit. ; Continue here if nobody was waiting for the semaphore. In this ; case just clear the semaphore's owner field. FC2E46 clr.l $28(A0) Clear ss_Owner to null. FC2E4A jsr -$8A(A6) Permit() FC2E4E rts ; Put up an alert if the semaphore's nest count went negative ; (should never happen, we give away the semaphore when it reaches ; zero), or if the semaphore's queue was empty even though the ; ss_QueueCount said it isn't. FC2E50 movem.l D7/A5/A6,-(SP) FC2E54 move.l #$81000008,D7 Alert number (fatal). FC2E5A move.l 4,A6 Get ExecBase. FC2E5E jsr -$6C(A6) Put up the alert. FC2E62 movem.l (SP)+,D7/A5/A6 Never executed. FC2E66 bra.s FC2E4E --------------------------------------------------------------------------- success = AttemptSemaphore( signalSemaphore ) D0 A0 --------------------------------------------------------------------------- FC2E68 move.l $0114(A6),A1 Get pointer to current task. FC2E6C addq.b #1,$0127(A6) Forbid() FC2E70 addq.w #1,$2C(A0) Increment the ss_QueueCount. FC2E74 beq.s FC2E88 Branch if now zero. FC2E76 cmp.l $28(A0),A1 Do we own the semaphore already? FC2E7A beq.s FC2E8C Branch if true. FC2E7C subq.w #1,$2C(A0) Decrement the ss_QueueCount again. FC2E80 jsr -$8A(A6) Permit() FC2E84 moveq #0,D0 Return FALSE. FC2E86 bra.s FC2E96 ; Continue here if we were able to get the semaphore. FC2E88 move.l A1,$28(A0) Install pointer to owning task. FC2E8C addq.w #1,$0E(A0) Increment nest count. FC2E90 jsr -$8A(A6) Permit() FC2E94 moveq #1,D0 Return TRUE. FC2E96 rts --------------------------------------------------------------------------- ObtainSemaphoreList( list ) A0 --------------------------------------------------------------------------- ; This function is given a linked list of semaphore structures, and ; obtains them all. This is done in two passes. On the first pass, ; a SemaphoreRequest is enqueued on all semaphores which aren't free, ; and all the free ones are grabbed. ; On the second pass, the list is traversed again. This time, if ; we already have a semaphore, we just pass it, otherwise, we wait ; for it. ; Note: Whereas ObtainSemaphore() builds its SemaphoreRequest node ; on the task's stack, this one uses the single copy inside the ; semaphore structure. This means that a crash is sure to result ; if more than one task tries to ObtainSemaphoreList and several ; end up waiting for the same semaphore. The documentation has ; a bit more to say about this. FC2E98 movem.l D2/A2/A3,-(SP) FC2E9C moveq #0,D1 Clear the "need to wait" flag. FC2E9E move.l $0114(A6),A2 Get pointer to current task. FC2EA2 addq.b #1,$0127(A6) Forbid() FC2EA6 move.l A0,A3 FC2EA8 move.l 0(A3),D2 Point to first semaphore in list. FC2EAC move.l D2,A1 FC2EAE move.l (A1),D2 End of list reached? FC2EB0 beq.s FC2EDC Exit loop if so. FC2EB2 addq.w #1,$2C(A1) Increment current semaphore's count. FC2EB6 beq.s FC2ED2 Branch if now zero. FC2EB8 cmp.l $28(A1),A2 Check if the semaphore is ours. FC2EBC beq.s FC2ED6 Branch if true. FC2EBE move.l A2,$24(A1) Use the ss_MultipleLink structure FC2EC2 lea $10(A1),A0 to enqueue our semaphore request on FC2EC6 lea $1C(A1),A1 the semaphore's wait queue. FC2ECA bsr FC15E8 FC2ECE moveq #1,D1 Indicate that we need to wait. FC2ED0 bra.s FC2EAC Go to next semaphore in list. ; We got a semaphore. FC2ED2 move.l A2,$28(A1) Make us the owner of this semaphore. FC2ED6 addq.w #1,$0E(A1) Increment its nest count. FC2EDA bra.s FC2EAC Try next semaphore in the list. ; The end of the list was reached. FC2EDC tst.l D1 Did we get all the semaphores? FC2EDE beq.s FC2F04 If so, exit. ; We have to wait for at least one semaphore in the list. FC2EE0 move.l 0(A3),D2 Go to the start of the list. FC2EE4 move.l D2,A3 FC2EE6 move.l (A3),D2 End of list reached? FC2EE8 beq.s FC2F04 If so, exit. FC2EEA cmp.l $28(A3),A2 Do we own this semaphore? FC2EEE bne.s FC2EFC FC2EF0 tst.w $0E(A3) If we do, and its nest count is not FC2EF4 bne.s FC2EE4 zero, go on to the next one. FC2EF6 addq.w #1,$0E(A3) Increment the nest count. FC2EFA bra.s FC2EE4 Go on to the next one. ; Wait for a semaphore. FC2EFC moveq #$10,D0 FC2EFE jsr -$013E(A6) Wait for signal #2. FC2F02 bra.s FC2EEA Go back and check if we have it now. FC2F04 jsr -$8A(A6) Permit() FC2F08 movem.l (SP)+,D2/A2/A3 FC2F0C rts --------------------------------------------------------------------------- ReleaseSemaphoreList( list ) A0 --------------------------------------------------------------------------- FC2F0E move.l D2,-(SP) FC2F10 move.l 0(A0),D2 Go to the start of the list. FC2F14 move.l D2,A0 Go to first/next node. FC2F16 move.l (A0),D2 End of list reached? FC2F18 beq.s FC2F20 If so, exit. FC2F1A jsr -$023A(A6) ReleaseSemaphore() FC2F1E bra.s FC2F14 Loop until all done. FC2F20 move.l (SP)+,D2 FC2F22 rts --------------------------------------------------------------------------- AddSemaphore( signalSemaphore ) A1 --------------------------------------------------------------------------- FC2F24 jsr -$022E(A6) InitSemaphore() FC2F28 lea $0214(A6),A0 Point to global semaphore list. FC2F2C bra FC1682 Add the semaphore to the list. --------------------------------------------------------------------------- RemSemaphore( signalSemaphore ) A1 --------------------------------------------------------------------------- FC2F30 bra FC168E Unlink semaphore from whatever list it's in. --------------------------------------------------------------------------- signalSemaphore = FindSemaphore( name ) D0 A1 --------------------------------------------------------------------------- FC2F34 lea $0214(A6),A0 Point to global semaphore list. FC2F38 jsr -$0114(A6) FindName() FC2F3C rts FC2F3E 0000 Padding. --------------------------------------------------------------------------- CopyMemQuick( source, dest, size ) A0 A1 D0 --------------------------------------------------------------------------- ; The caller guarantees that the source and destination are even, ; and that the transfer count is a multiple of 4. This allows us ; to skip some of the strategy below. FC2F40 moveq #0,D1 0 bytes left over after longword copy. FC2F42 bra.s FC2F64 Go copy (at least) as longwords. --------------------------------------------------------------------------- CopyMem( source, dest, size ) A0 A1 D0 --------------------------------------------------------------------------- ; This is an interesting tutorial on efficient 68000 memory moving. ; Note that this is not necessarily the best way to move memory on ; a 68010 or 68020, since both of these processors have expanded ; features designed to make memory moving more efficient, and all ; the computational overhead of choosing the right copying method ; might not be worth it. FC2F44 moveq #$0C,D1 Less than 12 bytes to copy? FC2F46 cmp.l D1,D0 FC2F48 bcs.s FC2FA2 If so, just copy byte by byte. ; The following bit of code handles odd/even source and destination ; addresses. The following is done: ; Source and destination even: Just continue. ; Source and destination odd: Copy 1 byte. Both addresses are now ; even, so we can continue. ; Source even, dest. odd: Copy byte by byte. ; Source odd, destination even: Copy one byte, then copy the rest ; byte by byte. ; Note that there is nothing we can do if the source and destination ; differ by an odd number, i.e. are "out of phase". In such a case, ; we must copy byte by byte. FC2F4A move.l A0,D1 FC2F4C btst #0,D1 Is the source address odd? FC2F50 beq.s FC2F56 Branch past the following if not. FC2F52 move.b (A0)+,(A1)+ Copy one byte. FC2F54 subq.l #1,D0 Decrement transfer count. FC2F56 move.l A1,D1 FC2F58 btst #0,D1 Is the destination address odd? FC2F5C bne.s FC2FA2 If so, transfer byte by byte. ; Both the source and destination addresses are (now) even. ; The worst that can happen now is that we have to move the data ; as individual longwords. First, compute how many bytes will ; be left over after we move the data as longwords, and save this ; value. FC2F5E move.l D0,D1 Find how many bytes will be left FC2F60 and.w #3,D1 if data is copied as longwords. FC2F64 move.w D1,-(SP) Save this number. ; The "move multiple" approach below copies 48 bytes of data with ; only two instructions. But to use it, 48 bytes of registers need ; to be saved and restored, and so it's not worth it unless we have ; at least two 48 byte "batches" to copy. FC2F66 moveq #$60,D1 FC2F68 cmp.l D1,D0 96 or more bytes to move? FC2F6A bcs.s FC2F86 If not, copy as longwords. FC2F6C movem.l D1-D7/A2-A6,-(SP) Save 12 registers on the stack. FC2F70 movem.l (A0)+,D1-D7/A2-A6 Get 48 bytes with one instruction. FC2F74 movem.l D1-D7/A2-A6,(A1) Move them to the destination. FC2F78 moveq #$30,D1 FC2F7A add.l D1,A1 Add 48 to destination address. FC2F7C sub.l D1,D0 Subtract 48 from transfer count. FC2F7E cmp.l D1,D0 Copy another batch if 48 or more FC2F80 bcc.s FC2F70 bytes remain to be copied. FC2F82 movem.l (SP)+,D1-D7/A2-A6 Restore the 12 registers. ; Whatever the case, D0 now contains the number of bytes left over. ; Copy as many of these as possible as longwords. FC2F86 lsr.l #2,D0 See how many longwords to copy. FC2F88 beq.s FC2F9A Branch if none. FC2F8A subq.l #1,D0 Adjust for dbra. FC2F8C move.l D0,D1 Split up into two 16-bit values. FC2F8E swap D0 FC2F90 move.l (A0)+,(A1)+ Copy the longwords. FC2F92 dbra D1,FC2F90(PC) FC2F96 dbra D0,FC2F90(PC) ; Done copying longwords. Get the number of bytes left over (0-3) ; from the stack and fall into the byte copy routine. FC2F9A move.w (SP)+,D1 Restore number of bytes left over. FC2F9C beq.s FC2FB2 Exit if none. FC2F9E moveq #0,D0 High 16 bits of byte count = 0. FC2FA0 bra.s FC2FAA Enter the byte copy loop. ; Copy as individual bytes, either to clean up odds and ends after ; copying in larger chunks, or because copying in larger chunks ; wasn't worth it. FC2FA2 move.w D0,D1 Split transfer count up into two FC2FA4 swap D0 16-bit sections. FC2FA6 bra.s FC2FAA Enter loop at bottom (for dbra). FC2FA8 move.b (A0)+,(A1)+ Copy the bytes. FC2FAA dbra D1,FC2FA8(PC) FC2FAE dbra D0,FC2FA8(PC) FC2FB2 rts ; System exception alert entry point ; ---------------------------------- ; If an exception occurs or a TRAP instruction is executed while the ; CPU is in supervisor mode, we jump here, since we have no task to ; blame it on. If a task was running, we use its tc_TrapCode vector ; instead, but at powerup, the exec default for this vector is also ; initialized to point here. Later, it is stolen by some other ; part of the system so the "Software error - task held" window can ; be put up before the guru. FC2FB4 movem.l D0-D7/A0-A7,$0180 Dump the registers. FC2FBA lea 2(SP),A5 Point at exception data on the stack. FC2FBE move.l 4,D0 Get ExecBase. FC2FC2 btst #0,D0 Is it even? FC2FC6 bne.s FC2FCE FC2FC8 move.l D0,A0 If so, point where the current task FC2FCA lea $0114(A0),A5 pointer probably is. FC2FCE move.l (SP),D7 Get the exception number. FC2FD0 and.l #$00FFFF,D7 Mask out any garbage. ; Fall into Alert(). alertNum is the exception number from the ; stack, and A5 points either to the current task pointer, or to ; the exception data on the stack. --------------------------------------------------------------------------- Alert( alertNum, parameters ) D7 A5 --------------------------------------------------------------------------- ; This routine has a relatively failsafe mechanism for getting an ; alert message up on the screen. I call this the "deferred guru". ; Right away, a signature ("HELP") is installed at location 0, and ; the guru data is stored at location $000100. If the system hangs ; now, the user will get the guru after he/she reboots manually ; via CTRL-Amiga-Amiga. If for any reason it decides it's in ; serious trouble, it will reset itself, with the same effect. FC2FD6 move.w #$4000,DFF09A Disable all interrupts. FC2FDE move.l #$48454C50,D0 ; If location 0 ALREADY contains "HELP", something is wrong, and ; no matter what the requested alert was, we reset the computer. FC2FE4 cmp.l 0,D0 See if "HELP" is at location zero. FC2FE8 beq FC305E If so, unrecoverable crash. ; Store our own "deferred guru" data at 0 and $000100. Then see ; if we should use it. If ExecBase has been clobbered, or the ; stack is not working, or the unrecoverable alert bit is set, ; we blink the power light, and reset the computer. The guru will ; come up during the reboot. FC2FEC move.l D0,0 Move "HELP" at location 0 now. FC2FF0 lea $0100,A0 Point at location $000100. FC2FF4 move.l D7,(A0)+ Store alert number there. FC2FF6 move.l (A5),(A0)+ Store the parameter. FC2FF8 move.l 4,D0 Get ExecBase. FC2FFC move.l D0,D1 ; Without checking, I would assume that this is where the famous ; "Recoverable alert doesn't work with expansion memory" bug is. ; Namely, if the ExecBase structure isn't in the first 64K of ; memory, we assume that it isn't OK. With $C00000 memory, it ; will be at $C00276, and KABOOM, this fails, and the system ; resets, doing the unrecoverable alert thing via the "deferred ; alert" mechanism discussed earlier. FC2FFE and.l #$FF0001,D1 Is ExecBase in the first 64K? FC3004 bne.s FC305E If not, unrecoverable crash. FC3006 move.l D0,A6 FC3008 add.l $26(A6),D0 Check ExecBase complement pointer. FC300C addq.l #1,D0 FC300E bne.s FC305E Unrecoverable crash if not valid. FC3010 move.l #$F1E2D3C4,D0 Check if the stack is working by FC3016 move.l D0,-(SP) pushing a signature and trying to FC3018 cmp.l (SP)+,D0 pop it off again. FC301A bne.s FC3054 Unrecoverable crash if not working. FC301C tst.l D7 Test high bit of alert number. FC301E bmi.s FC305E Branch if unrecoverable. ; Processing for recoverable alerts. If we get this far, we have ; verified that the "dead end alert" flag was not set, that the ; ExecBase pointer and structure are probably OK, and that the ; stack is working (stack pointer pointing to RAM). FC3020 lea $0202(A6),A0 Point to ExecBase->LastAlert. FC3024 move.l D7,(A0)+ Store alert number. FC3026 move.l (A5),(A0)+ Store parameter. FC3028 bsr FC30EC Call the guru alert routine. FC302C and.l #$FFFF0000,D7 Was the subsystem ID field zero? FC3032 bne.s FC3044 If not, return to the caller. ; The alert number was of the form 0000xxxx. This means that it ; must have been a system exception. Presumably, the user has had ; the option of pressing the left or right mouse button, reflected ; in D0 as returned from the guru routine. Accordingly, we ; reset or go to the debugger. FC3034 tst.l D0 Test the guru routine's return code. FC3036 movem.l $0180,D0-D7/A0-A7 Restore the registers. FC303C bne FC05F0 Reset if zero flag not set. FC3040 bra FC2342 Else go to ROM-Wack. FC3044 tst.l $0126(A6) Enable interrupts if they are FC3048 bge.s FC3052 supposed to be enabled. FC304A move.w #$C000,DFF09A FC3052 rts ; Unrecoverable system crash entry point ; -------------------------------------- ; This routine blinks the power light slowly 6 times, and checks ; whether the user presses DEL on a terminal attached to the ; serial port. If DEL is received, it jumps to ROM-Wack. If ; DEL is not received, it resets the computer. This may or may ; not lead to a guru, depending on how locations 0 and $000100 were ; set up before this was called. ; Entry point for when the stack is not working (stack pointer ; clobbered). Set the stack pointer to 256K, and build a fake ; exception stack frame below it. FC3054 move.l #$040000,SP Set stack pointer to 256K FC305A clr.l -(SP) Build fake exception stack frame. FC305C clr.w -(SP) ; Entry point for when the stack was working. FC305E or.b #3,BFE201 Set CIA data direction register. FC3066 and.b #$FE,BFE001 Set power light to bright. ; Force the CPU into supervisor mode. If the MOVE.W #$2700,SR ; instruction bombs the first time, it will work the second time. FC306E move.l #$FC3076,$20 Set privilege violation vector. FC3076 move.w #$2700,SR Mask all maskable interrupts. ; Blink the power light slowly 6 times and look for a DEL character ; coming in through the serial port at 9600 bps. If such a character ; is received, go to the debugger. FC307A moveq #5,D1 Set loop counter to 5. FC307C move.w #$0174,DFF032 Set serial port for 8 bits, 9600 bps. FC3084 moveq #-1,D0 FC3086 bset #1,BFE001 Set power light to dim. FC308E dbra D0,FC3086(PC) Delay. FC3092 bclr #1,BFE001 Set power light to bright. FC309A dbra D0,FC3092(PC) Delay. FC309E move.w DFF018,D0 Read the serial port. FC30A4 move.w #$0800,DFF09C Clear serial port interrupt bit. FC30AC and.b #$7F,D0 FC30B0 cmp.b #$7F,D0 Did we receive a DEL character? FC30B4 dbeq D1,FC3084(PC) If not, keep blinking the light. FC30B8 bmi FC05F0 If DEL not pressed, reset. ; The user pressed DEL. Push the exception number on the stack ; and enter the debugger. FC30BC move.l D7,-(SP) FC30BE jmp FC2342 Go to ROM-Wack. ; "Deferred Guru" support routines ; -------------------------------- ; The following routine is called early in the startup code. Since ; there is no stack at that point, it returns via a jump, rather ; than an RTS. It removes the "HELP" at zero, if present, and ; loads D6 and D7 with the data for ExecBase->LastAlert. FC30C4 move.l #$FFFFFFFF,D6 Load -1 into D6 FC30CA cmp.l #$48454C50,0 See if location 0 contains "HELP". FC30D2 bne FC014C If not, go back to init. code. FC30D6 clr.l 0 Clear location 0. FC30DA movem.l $0100,D6/D7 Load D6 and D7 from location $0100. FC30E0 bra FC014C Go back to init. code. ; The following subroutine is called later, after the ExecBase ; structure has been built. It writes the data determined above ; (still in D6 and D7) into ExecBase->LastAlert. FC30E4 movem.l D6/D7,$0202(A6) FC30EA rts ; Guru Alert Routine ; ------------------ ; This routine puts the big red "Guru" message up on the screen, ; waits for the user to click the mouse button, then returns. ; The routine is called with the alert number and parameters stored ; at LastAlert in the ExecBase structure. This routine reads the ; alert number from there and decides what to do with it. ; An alert number of -1 means that no alert was outstanding, and ; therefore, the routine returns right away. This means that if ; it is called via the "alert.hook" mechanism, and no alert was ; pending from before the reboot, nothing will happen. ; If the alert number is not -1, an alert will be generated. The ; following algorithm is used to decide what the first string in ; the alert should say. ; IF the alert number is of the form xxxx01xxxxxxxx THEN ; Make the alert message "Not enough memory". ; ELSEIF the high bit in the alert number is clear, and the ; "general error" field is not zero THEN ; Make the alert message "Recoverable Alert". ; ELSE ; Make the alert message "Software Failure". ; ENDIF ; When the alert is finished (the user pressed the mouse button), ; the LastAlert field in ExecBase is cleared to -1, and the longword ; at location 0 is cleared to zero. FC30EC movem.l D2/D7/A2/A3/A6,-(SP) FC30F0 moveq #$0A,D1 Delay for a while. FC30F2 moveq #-1,D0 FC30F4 dbra D0,FC30F4(PC) FC30F8 dbra D1,FC30F4(PC) FC30FC move.l $0202(A6),D2 Get the alert number. FC3100 moveq #-1,D0 Compare to -1 (indicates no alert). FC3102 cmp.l D0,D2 FC3104 beq.s FC317C Exit if equal. FC3106 lea -$C8(SP),SP Reserve 200 bytes of stack space. FC310A lea (SP),A3 Point to base of reserved area. ; Decide which alert message to use. FC310C lea FC31AA(PC),A0 Point to "Software Failure" string. FC3110 move.l D2,D0 Get the alert number. FC3112 swap D0 Get the general error number. FC3114 cmp.b #1,D0 Is it an AG_NoMemory type of alert? FC3118 bne.s FC3120 If so, point to "Not enough Memory" FC311A lea FC3194(PC),A0 string. FC311E bra.s FC312E FC3120 btst #$1F,D2 If otherwise, check the dead-end FC3124 bne.s FC312E alert flag. If it is clear, but FC3126 tst.w D0 the Subsystem/General error fields FC3128 beq.s FC312E are not zero, then point to the FC312A lea FC31BF(PC),A0 "Recoverable Alert" string. FC312E bsr.s FC318A Copy the string into the buffer. FC3130 lea FC31D5(PC),A0 Point to "Press left mouse button..." FC3134 bsr.s FC318A Copy the string into the buffer. FC3136 clr.b (A3)+ Put a zero into the buffer. FC3138 lea FC31FC(PC),A0 Point to "Guru Meditation..." string. FC313C lea $0202(A6),A1 Point to alert data. FC3140 lea FC3184(PC),A2 Point to character output routine. FC3144 jsr -$020A(A6) RawDoFmt() FC3148 lea FC321B(PC),A1 Point to "intuition.library". FC314C moveq #0,D0 Minimum version is 0 (any). FC314E jsr -$0228(A6) OpenLibrary() FC3152 tst.l D0 Did it open OK? FC3154 beq.s FC316E If not, skip the following. FC3156 move.l A6,A3 Save ExecBase. FC3158 move.l D0,A6 Get IntuitionBase. FC315A clr.l D0 Tell intuition that the alert # is 0. FC315C lea (SP),A0 Point to the alert string. FC315E moveq #$28,D1 Alert should be 40 video lines high. FC3160 jsr -$5A(A6) DisplayAlert() FC3164 move.l D0,A2 FC3166 move.l A6,A1 Get IntuitionBase. FC3168 move.l A3,A6 Restore ExecBase. FC316A jsr -$019E(A6) CloseLibrary() FC316E lea $C8(SP),SP Deallocate string space on stack. FC3172 clr.l 0 Remove "HELP" at 0, if present. FC3176 moveq #-1,D0 FC3178 move.l D0,$0202(A6) Set LastAlert to -1. ; Set the return code. If intuition.library didn't open, A2 contains ; a non-zero address, so a non-zero return value results. If ; intuition could be called, this is the return code from the ; DisplayAlert() call. FC317C move.l A2,D0 Set return code. FC317E movem.l (SP)+,D2/D7/A2/A3/A6 FC3182 rts ; Character output routine for RawDoFmt() while putting together ; the "Guru Meditation #..." message. FC3184 move.b D0,(A3)+ Put character in buffer. FC3186 clr.b (A3) Zero-terminate the buffer. FC3188 rts ; Routine to copy a given string to the output buffer while ; building the guru message. FC318A clr.b (A3)+ Put a zero into the buffer. FC318C move.b (A0)+,(A3)+ Copy the given string. FC318E bne.s FC318C FC3190 st (A3)+ Terminate buffer with $FF. FC3192 rts ; Strings used for the guru message. FC3194 "&", 0F, "Not enough memory. ", 00 FC31AA "&", 0F, "Software Failure. ", 00 FC31BF "&", 0F, "Recoverable Alert. ", 00 FC31D5 EA, 0F, "Press left mouse button to continue.", 00 FC31FC 8E, 1E, "Guru Meditation #%08lx.%08lx", 00 ; Name used to open intuition to put up the alert. FC321B "intuition.library", 00 ; The "alert.hook" mechanism ; -------------------------- ; This is a RomTag. At system startup, this will be found and added ; to the resident module list. Since it has the RTW_COLDSTART flag ; set, it will be initialized along with the other libraries, ; devices, etc. The RTF_AUTOINIT flag is not set, therefore, the ; code at RT_INIT is called. ; The code at RT_INIT is the Guru routine. This reads the LastAlert ; field in ExecBase. If this is not -1, then an alert is still ; outstanding (from before the reboot), and this puts it up, lets ; the user click the mouse button, then returns. The resident ; module initialization then continues, the DOS boots, and the ; system comes up. ; The purpose of all this is to allow the system to defer display ; of a guru message until after the system has been cold-started. FC322D "alert.hook", CR, LF, 00 FC323A 4AFC RTC_MATCHWORD (start of ROMTAG marker) FC323C 00FC323A RT_MATCHTAG (pointer RTC_MATCHWORD) FC3240 00FC3254 RT_ENDSKIP (pointer to end of code) FC3244 01 RT_FLAGS (RTW_COLDSTART) FC3245 21 RT_VERSION (33 decimal) FC3246 00 RT_TYPE (NT_UNKNOWN) FC3247 05 RT_PRI (priority = 5) FC3248 00FC322D RT_NAME (pointer to name) FC324C 00FC322D RT_IDSTRING (pointer to ID string) FC3250 00FC30EC RT_INIT (execution address) ; ROM-Wack command dispatch tables ("Key bindings"). ; -------------------------------------------------- ; ROM-Wack can be in one of two modes when a key is pressed. It can ; be waiting for a command, or it can be in the process of gathering ; a multi character command. The two tables below decide what to do ; with the key in each case. ; Each table entry has 4 fields. These are, address of next table ; entry to try if key doesn't match this one, lowest key value for ; this table entry, highest key value (if several) or zero, address ; to jump to. ; Primary command dispatch table. FC3254 00FC325E 04 00 00FC2442 ^D FC325E 00FC3268 0D 00 00FC2510 FC3268 00FC3272 09 00 00FC2426 FC3272 00FC327C 3F 00 00FC2B06 ? FC327C 00FC3286 2E 00 00FC2562 . FC3286 00FC3290 2C 00 00FC2572 , FC3290 00FC329A 3E 00 00FC2522 > FC329A 00FC32A4 3C 00 00FC2542 < FC32A4 00FC32AE 08 00 00FC2542 FC32AE 00FC32B8 20 00 00FC2522 FC32B8 00FC32C2 5B 00 00FC2582 [ FC32C2 00FC32CC 5D 00 00FC25A0 ] FC32CC 00FC32D6 3A 00 00FC2602 : FC32D6 00FC32E0 2B 00 00FC25B4 + FC32E0 00FC32EA 2D 00 00FC25D4 - FC32EA 00FC32F4 3D 00 00FC2642 = FC32F4 00FC32FE 21 00 00FC2938 ! FC32FE 00FC3308 5E 00 00FC29B2 ^ FC3308 00FC3312 5F 00 00FC2BA0 _ FC3312 00FC331C 30 39 00FC2BA0 0 - 9 FC331C 00FC3326 61 7A 00FC2BA0 a - z FC3326 00FC3330 41 5A 00FC2BA0 A - Z FC3330 00000000 End of table marker. ; Secondary command dispatch table (used while a command ; and/or address is being typed). FC3334 00FC333E 08 00 00FC2C44 FC333E 00FC3348 0D 00 00FC2C6E FC3348 00FC3352 18 00 00FC2C2C FC3352 00FC335C 15 00 00FC2C2C FC335C 00FC3366 3E 00 00FC2522 > FC3366 00FC3370 3C 00 00FC2542 < FC3370 00FC337A 20 00 00FC2C2A FC337A 00FC3384 5F 00 00FC2BA0 _ FC3384 00FC338E 30 39 00FC2BA0 0 - 9 FC338E 00FC3398 61 7A 00FC2BA0 a - z FC3398 00FC33A2 41 5A 00FC2BA0 A - Z FC33A2 00000000 End of table marker. ; Table of multi-character ROM-Wack commands. FC33A6 "alter", 00, "boot", 00, "clear", 00, "fill", 00 FC33BC "find", 00, "go", 00, "ig", 00, "limit", 00, "list", 00 FC33D2 "regs", 00, "reset", 00, "resume", 00, "set", 00 FC33E8 "show", 00, "user", 00, 00, 00 ; Dispatch table for multicharacter commands. ; The fields are link to next table entry, address of command string, ; an unused value (presumably from a larger version of Wack), and ; the address to jump to for that command. FC33F4 00FC3402 00FC33A6 0001 00FC2670 "alter" FC3402 00FC3410 00FC33AC 0001 00FC05F0 "boot" FC3410 00FC341E 00FC33B1 0001 00FC28A2 "clear" FC341E 00FC342C 00FC33B7 0001 00FC2A38 "fill" FC342C 00FC343A 00FC33BC 0001 00FC29C0 "find" FC343A 00FC3448 00FC33C1 0001 00FC2438 "go" FC3448 00FC3456 00FC33C4 0001 00FC05F0 "ig" FC3456 00FC3464 00FC33C7 0001 00FC29B2 "limit" FC3464 00FC3472 00FC33CD 0001 00FC26B2 "list" FC3472 00FC3480 00FC33D2 0001 00FC27E6 "regs" FC3480 00FC348E 00FC33D7 0001 00FC28B2 "reset" FC348E 00FC349C 00FC33DD 0001 00FC2442 "resume" FC349C 00FC34AA 00FC33E4 0001 00FC28D0 "set" FC34AA 00FC34B8 00FC33E8 0001 00FC290A "show" FC34B8 00FC34C6 00FC33ED 0001 00FC24B2 "user" FC34C6 00000000 FC34CA 0000 Padding. ; That's it. The next RomTag (for the audio.device) comes right ; after the two bytes of padding shown above. .