ack/plat/cpm/libsys/_trap.s

#
! $Source$
! $State$
! $Revision$

#
#include "asm.h"

.define .trp
.define EARRAY, ERANGE, ESET, EIOVFL, EFOVFL, EFUNFL, EIDIVZ, EIDIVZ
.define EFDIVZ, EIUND, EFUND, ECONV, ESTACK, EHEAP, EILLINS, EODDZ
.define ECASE, EMEMFLT, EBADPTR, EBADPC, EBADLAE, EBADMON, EBADLIN, EBADGTO
.define EUNIMPL

! Trap routine
! Expects trap number in A, and must be called directly from the code
! where execution should resume (for those traps which support it).
! Just returns if trap has to be ignored.
! Otherwise it calls a user-defined trap handler if provided.
! When no user-defined trap handler is provided or when the user-defined
! trap handler causes a new trap, a message is printed
! and control is returned to the monitor.

	EARRAY	=  0
	ERANGE	=  1
	ESET	=  2
	EIOVFL	=  3
	EFOVFL	=  4
	EFUNFL	=  5
	EIDIVZ	=  6
	EFDIVZ	=  7
	EIUND	=  8
	EFUND	=  9
	ECONV	= 10
	ESTACK  = 16
	EHEAP	= 17
	EILLINS = 18
	EODDZ	= 19
	ECASE	= 20
	EMEMFLT	= 21
	EBADPTR = 22
	EBADPC  = 23
	EBADLAE = 24
	EBADMON = 25
	EBADLIN = 26
	EBADGTO = 27
	EUNIMPL = 63		! unimplemented em-instruction called

.trp:
	mov a,l
	cpi 16
	jnc 3f			! jump if trap cannot be ignored

! check if trap has to be ignored
	xchg			! de = trap number
	lhld .ignmask
	push h			! hl = set to be tested
	push d
	call .inn2		! de = 1 if bit is set, 0 otherwise
	mov a,e
	rar
	jnc 3f			! jump if trap should not be ignored
	pop h			! remove trap number
	ret			! OGEN DICHT EN ... SPRING!!!

3:
.define .trapproc
.trapproc = . + 1
	lxi h, 0            ! user defined trap handler held inline here
	mov a,l
	ora h
	jz 1f	     		! jump if there was not
	xra a
	sta .trapproc		! .trapproc := 0
	sta .trapproc+1
	lxi d,2f		
	push d
	pchl			! call user defined trap handler
2:
	pop d
	ret
1:
	lxi d, text
	mvi c, 9        ! write $-terminated string
	call 0x0005
	rst 0           ! abend

.sect .rom
text: .ascii "TRAP!\r\n$"