Simplify the .trp API to make it a bit smaller.

mach/i80/ncg/table

@@ -2475,5 +2475,6 @@ with hlreg
 gen shld {label,".reghp"}
 
 pat trp
-kills ALL
-gen Call {label,".trp"}
+   with areg
+      kills ALL
+      gen Call {label,".trp"}

plat/cpm/boot.s

@@ -170,8 +170,7 @@ _cpm_cmdline = 0x0081
 
 ! Some magic data. All EM systems need these.
 
-.define .trppc, .ignmask, _errno
-.comm .trppc, 2
+.define .ignmask, _errno
 .comm .ignmask, 2
 .comm _errno, 2
 
@@ -184,11 +183,10 @@ envp: .space 2          ! envp array (always empty, must be after argv)
 
 ! These are used specifically by the i80 code generator.
 
-.define .trapproc, .retadr, .retadr1
+.define .retadr, .retadr1
 .define .bcreg, .areg
 .define .tmp1, .fra, block1, block2, block3
 
-.comm .trapproc, 2
 .comm .retadr, 2        ! used to save return address
 .comm .retadr1, 2       ! reserve
 .comm .bcreg, 2

plat/cpm/libsys/_trap.s

@@ -13,7 +13,8 @@
 .define EUNIMPL
 
 ! Trap routine
-! Expects trap number on stack.
+! 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
@@ -46,9 +47,6 @@
 	EUNIMPL = 63		! unimplemented em-instruction called
 
 .trp:
-	pop h
-	xthl
-	push h			! trap number and return address exchanged
 	mov a,l
 	cpi 16
 	jnc 3f			! jump if trap cannot be ignored
@@ -66,10 +64,12 @@
 	ret			! OGEN DICHT EN ... SPRING!!!
 
 3:
-	lhld .trapproc		! user defined trap handler?
+.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
+	jz 1f	     		! jump if there was not
 	xra a
 	sta .trapproc		! .trapproc := 0
 	sta .trapproc+1

plat/cpm/libsys/make_trap.sh

@@ -4,9 +4,7 @@ cat <<EOF
 #include "asm.h"
 .define $1
 $1:
-    lxi h, $2
-	push h
-	call .trp
-	ret
+	mvi a, $2
+	jmp .trp
 EOF