$NetBSD: README.mach-traps,v 1.3 2001/06/04 20:06:41 nathanw Exp $

Some Alpha AXP OSF/1 binaries directly use the facilities provided by
the Mach kernel that is the basis for OSF/1.  These include (but are
surely not limited to) 'dd', 'ps', and 'w'.

Invariably, the symptom that these binaries display is that they crash
with an "unimplemented system call" trap (SIGSYS signal) for a syscall
that has a negative number.  In general, binaries that use the Mach
syscalls appear to invoke task_self() as their first syscall.

Note that system call numbers are now range-bounded by masking off the
high bits, so negative system call numbers will appear in the high
end of the system call number range, thanks to the wonders of two's
compliment arithmetic. System call -10, for example, will appear as
"CALL  [502]" in kdump output.

The name, number, and number of arguments for each Mach syscall is
given below; this information was gleaned by looking through the OSF/1
libmach.a's object files with dbx, then double-checked against the
contents of OSF/1's <mach/syscall_sw.h>.

These calls would be very difficult to implement properly in the
OSF/1 emulation code; by its very nature, NetBSD is not Mach, and we
don't and can't provide the underlying facilities that it does.

-- cgd

trap name			number	nargs	notes
---- ----			------	-----	-----
task_self			-10	0
thread_reply			-11	0
task_notify			-12	0
thread_self			-13	0
msg_send_old			-14	3
msg_receive_old			-15	3
msg_rpc_old			-16	5
msg_send_trap			-20	4
msg_receive_trap		-21	5
msg_rpc_trap			-22	6
lw_wire				-30	3
lw_unwire			-31	1
nxm_task_init			-33	2
nxm_sched_thread		-34	1
nxm_idle			-35	1
nxm_wakeup_idle			-36	1
nxm_set_pthid			-37	2
nxm_thread_kill			-38	2
nxm_thread_block		-39	1
nxm_thread_wakeup		-40	1
inode_swap_preference		-40	3	old call?
init_process			-41	0
map_fd				-43	5
nxm_resched			-44	2
htg_unix_syscall		-52	3
host_self			-55	1
host_priv_self			-56	1
swtch_pri			-59	1
swtch				-60	0
thread_switch			-61	3
semop_fast			-62	4
mach_sctimes_0			-70	0	only if MACH_SCTIMES defined
mach_sctimes_1			-71	1	only if MACH_SCTIMES defined
mach_sctimes_2			-72	2	only if MACH_SCTIMES defined
mach_sctimes_3			-73	3	only if MACH_SCTIMES defined
mach_sctimes_4			-74	4	only if MACH_SCTIMES defined
mach_sctimes_5			-75	5	only if MACH_SCTIMES defined
mach_sctimes_6			-76	6	only if MACH_SCTIMES defined
mach_sctimes_7			-77	0	only if MACH_SCTIMES defined
mach_sctimes_8			-78	6	only if MACH_SCTIMES defined
mach_sctimes_9			-79	1	only if MACH_SCTIMES defined
mach_sctimes_10			-80	2	only if MACH_SCTIMES defined
mach_sctimes_11			-81	2	only if MACH_SCTIMES defined
mach_sctimes_port_alloc_dealloc	-82	1	only if MACH_SCTIMES defined
