zasm: remove last remnants of "old style" variables

This makes zasm suitable to run from ROM.
This commit is contained in:
Virgil Dupras 2019-07-25 14:02:04 -04:00
parent 13028d431e
commit d1735c3a73
4 changed files with 69 additions and 71 deletions

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@ -78,8 +78,9 @@ jp zasmMain
#include "lib/parse.asm" #include "lib/parse.asm"
#include "zasm/parse.asm" #include "zasm/parse.asm"
#include "zasm/expr.asm" #include "zasm/expr.asm"
.equ INS_RAMSTART TOK_RAMEND
#include "zasm/instr.asm" #include "zasm/instr.asm"
.equ DIREC_RAMSTART TOK_RAMEND .equ DIREC_RAMSTART INS_RAMEND
#include "zasm/directive.asm" #include "zasm/directive.asm"
.equ SYM_RAMSTART DIREC_RAMEND .equ SYM_RAMSTART DIREC_RAMEND
#include "zasm/symbol.asm" #include "zasm/symbol.asm"

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@ -68,6 +68,15 @@
.equ I_SUB 0x3b .equ I_SUB 0x3b
.equ I_XOR 0x3c .equ I_XOR 0x3c
; *** Variables ***
; Args are 3 bytes: argspec, then values of numerical constants (when that's
; appropriate)
.equ INS_CURARG1 INS_RAMSTART
.equ INS_CURARG2 INS_CURARG1+3
.equ INS_UPCODE INS_CURARG2+3
.equ INS_RAMEND INS_UPCODE+4
; *** Code ***
; Checks whether A is 'N' or 'M' ; Checks whether A is 'N' or 'M'
checkNOrM: checkNOrM:
cp 'N' cp 'N'
@ -365,11 +374,11 @@ matchPrimaryRow:
cp (ix) cp (ix)
jr nz, .end jr nz, .end
; name matches, let's see the rest ; name matches, let's see the rest
ld hl, curArg1 ld hl, INS_CURARG1
ld a, (ix+1) ld a, (ix+1)
call matchArg call matchArg
jr nz, .end jr nz, .end
ld hl, curArg2 ld hl, INS_CURARG2
ld a, (ix+2) ld a, (ix+2)
call matchArg call matchArg
.end: .end:
@ -391,13 +400,13 @@ handleJPIX:
handleJPIY: handleJPIY:
ld a, 0xfd ld a, 0xfd
handleJPIXY: handleJPIXY:
ld (instrUpcode), a ld (INS_UPCODE), a
ld a, (curArg1+1) ld a, (INS_CURARG1+1)
cp 0 ; numerical argument *must* be zero cp 0 ; numerical argument *must* be zero
jr nz, .error jr nz, .error
; ok, we're good ; ok, we're good
ld a, 0xe9 ; second upcode ld a, 0xe9 ; second upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld c, 2 ld c, 2
ret ret
.error: .error:
@ -407,7 +416,7 @@ handleJPIXY:
; Handle the first argument of BIT. Sets Z if first argument is valid, unset it ; Handle the first argument of BIT. Sets Z if first argument is valid, unset it
; if there's an error. ; if there's an error.
handleBIT: handleBIT:
ld a, (curArg1+1) ld a, (INS_CURARG1+1)
cp 8 cp 8
jr nc, .error ; >= 8? error jr nc, .error ; >= 8? error
; We're good ; We're good
@ -429,13 +438,13 @@ _handleBITHL:
call handleBIT call handleBIT
ret nz ; error ret nz ; error
ld a, 0xcb ; first upcode ld a, 0xcb ; first upcode
ld (instrUpcode), a ld (INS_UPCODE), a
ld a, (curArg1+1) ; 0-7 ld a, (INS_CURARG1+1) ; 0-7
rla rla
rla rla
rla rla
or b ; 2nd upcode or b ; 2nd upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld c, 2 ld c, 2
ret ret
@ -463,19 +472,19 @@ handleRESIY:
ld a, 0xfd ld a, 0xfd
ld b, 0b10000110 ld b, 0b10000110
_handleBITIXY: _handleBITIXY:
ld (instrUpcode), a ; first upcode ld (INS_UPCODE), a ; first upcode
call handleBIT call handleBIT
ret nz ; error ret nz ; error
ld a, 0xcb ; 2nd upcode ld a, 0xcb ; 2nd upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld a, (curArg2+1) ; IXY displacement ld a, (INS_CURARG2+1) ; IXY displacement
ld (instrUpcode+2), a ld (INS_UPCODE+2), a
ld a, (curArg1+1) ; 0-7 ld a, (INS_CURARG1+1) ; 0-7
rla rla
rla rla
rla rla
or b ; 4th upcode or b ; 4th upcode
ld (instrUpcode+3), a ld (INS_UPCODE+3), a
ld c, 4 ld c, 4
ret ret
@ -491,13 +500,13 @@ _handleBITR:
call handleBIT call handleBIT
ret nz ; error ret nz ; error
; get group value ; get group value
ld a, (curArg2+1) ; group value ld a, (INS_CURARG2+1) ; group value
ld c, a ld c, a
; write first upcode ; write first upcode
ld a, 0xcb ; first upcode ld a, 0xcb ; first upcode
ld (instrUpcode), a ld (INS_UPCODE), a
; get bit value ; get bit value
ld a, (curArg1+1) ; 0-7 ld a, (INS_CURARG1+1) ; 0-7
rla rla
rla rla
rla rla
@ -505,12 +514,12 @@ _handleBITR:
; and we want to OR them together ; and we want to OR them together
or c ; Now we have our ORed value or c ; Now we have our ORed value
or b ; and with our "base" value and we're good! or b ; and with our "base" value and we're good!
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld c, 2 ld c, 2
ret ret
handleIM: handleIM:
ld a, (curArg1+1) ld a, (INS_CURARG1+1)
cp 0 cp 0
jr z, .im0 jr z, .im0
cp 1 cp 1
@ -529,9 +538,9 @@ handleIM:
.im2: .im2:
ld a, 0x5e ld a, 0x5e
.proceed: .proceed:
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld a, 0xed ld a, 0xed
ld (instrUpcode), a ld (INS_UPCODE), a
ld c, 2 ld c, 2
ret ret
@ -541,13 +550,13 @@ handleLDIXn:
handleLDIYn: handleLDIYn:
ld a, 0xfd ld a, 0xfd
handleLDIXYn: handleLDIXYn:
ld (instrUpcode), a ld (INS_UPCODE), a
ld a, 0x36 ; second upcode ld a, 0x36 ; second upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld a, (curArg1+1) ; IXY displacement ld a, (INS_CURARG1+1) ; IXY displacement
ld (instrUpcode+2), a ld (INS_UPCODE+2), a
ld a, (curArg2+1) ; N ld a, (INS_CURARG2+1) ; N
ld (instrUpcode+3), a ld (INS_UPCODE+3), a
ld c, 4 ld c, 4
ret ret
@ -557,12 +566,12 @@ handleLDIXr:
handleLDIYr: handleLDIYr:
ld a, 0xfd ld a, 0xfd
handleLDIXYr: handleLDIXYr:
ld (instrUpcode), a ld (INS_UPCODE), a
ld a, (curArg2+1) ; group value ld a, (INS_CURARG2+1) ; group value
or 0b01110000 ; second upcode or 0b01110000 ; second upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld a, (curArg1+1) ; IXY displacement ld a, (INS_CURARG1+1) ; IXY displacement
ld (instrUpcode+2), a ld (INS_UPCODE+2), a
ld c, 3 ld c, 3
ret ret
@ -572,34 +581,34 @@ handleLDrIX:
handleLDrIY: handleLDrIY:
ld a, 0xfd ld a, 0xfd
handleLDrIXY: handleLDrIXY:
ld (instrUpcode), a ld (INS_UPCODE), a
ld a, (curArg1+1) ; group value ld a, (INS_CURARG1+1) ; group value
rla \ rla \ rla rla \ rla \ rla
or 0b01000110 ; second upcode or 0b01000110 ; second upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
ld a, (curArg2+1) ; IXY displacement ld a, (INS_CURARG2+1) ; IXY displacement
ld (instrUpcode+2), a ld (INS_UPCODE+2), a
ld c, 3 ld c, 3
ret ret
handleLDrr: handleLDrr:
; first argument is displaced by 3 bits, second argument is not ; first argument is displaced by 3 bits, second argument is not
; displaced and we or that with a leading 0b01000000 ; displaced and we or that with a leading 0b01000000
ld a, (curArg1+1) ; group value ld a, (INS_CURARG1+1) ; group value
rla rla
rla rla
rla rla
ld c, a ; store it ld c, a ; store it
ld a, (curArg2+1) ; other group value ld a, (INS_CURARG2+1) ; other group value
or c or c
or 0b01000000 or 0b01000000
ld (instrUpcode), a ld (INS_UPCODE), a
ld c, 1 ld c, 1
ret ret
; Compute the upcode for argspec row at (DE) and arguments in curArg{1,2} and ; Compute the upcode for argspec row at (DE) and arguments in curArg{1,2} and
; writes the resulting upcode in instrUpcode. A is the number if bytes written ; writes the resulting upcode in INS_UPCODE. A is the number if bytes written
; to instrUpcode. ; to INS_UPCODE.
; A is zero on error. The only thing that can go wrong in this routine is ; A is zero on error. The only thing that can go wrong in this routine is
; overflow. ; overflow.
getUpcode: getUpcode:
@ -617,14 +626,14 @@ getUpcode:
ld l, (ix+4) ld l, (ix+4)
ld h, (ix+5) ld h, (ix+5)
call callHL call callHL
; We have our result written in instrUpcode and C is set. ; We have our result written in INS_UPCODE and C is set.
jp .end jp .end
.normalInstr: .normalInstr:
; we begin by writing our "base upcode", which can be one or two bytes ; we begin by writing our "base upcode", which can be one or two bytes
ld a, (ix+4) ; first upcode ld a, (ix+4) ; first upcode
ld (instrUpcode), a ld (INS_UPCODE), a
ld de, instrUpcode ; from this point, DE points to "where we are" ld de, INS_UPCODE ; from this point, DE points to "where we are"
; in terms of upcode writing. ; in terms of upcode writing.
inc de ; make DE point to where we should write next. inc de ; make DE point to where we should write next.
@ -656,10 +665,10 @@ getUpcode:
jr nz, .writeExtraBytes ; not a group? nothing to do. go to jr nz, .writeExtraBytes ; not a group? nothing to do. go to
; next step: write extra bytes ; next step: write extra bytes
; Second arg is group ; Second arg is group
ld hl, curArg2 ld hl, INS_CURARG2
jr .isGroup jr .isGroup
.firstArgIsGroup: .firstArgIsGroup:
ld hl, curArg1 ld hl, INS_CURARG1
.isGroup: .isGroup:
; A is a group, good, now let's get its value. HL is pointing to ; A is a group, good, now let's get its value. HL is pointing to
; the argument. Our group value is at (HL+1). ; the argument. Our group value is at (HL+1).
@ -681,11 +690,11 @@ getUpcode:
bit 6, (ix+3) bit 6, (ix+3)
jr z, .firstUpcode ; not set: first upcode jr z, .firstUpcode ; not set: first upcode
or (ix+5) ; second upcode or (ix+5) ; second upcode
ld (instrUpcode+1), a ld (INS_UPCODE+1), a
jr .writeExtraBytes jr .writeExtraBytes
.firstUpcode: .firstUpcode:
or (ix+4) ; first upcode or (ix+4) ; first upcode
ld (instrUpcode), a ld (INS_UPCODE), a
jr .writeExtraBytes jr .writeExtraBytes
.writeExtraBytes: .writeExtraBytes:
; Good, we are probably finished here for many primary opcodes. However, ; Good, we are probably finished here for many primary opcodes. However,
@ -693,15 +702,15 @@ getUpcode:
; if that's the case here, we need to write it too. ; if that's the case here, we need to write it too.
; We still have our instruction row in IX and we have DE pointing to ; We still have our instruction row in IX and we have DE pointing to
; where we should write next (which could be the second or the third ; where we should write next (which could be the second or the third
; byte of instrUpcode). ; byte of INS_UPCODE).
ld a, (ix+1) ; first argspec ld a, (ix+1) ; first argspec
ld hl, curArg1 ld hl, INS_CURARG1
call checkNOrM call checkNOrM
jr z, .withWord jr z, .withWord
call checknmxy call checknmxy
jr z, .withByte jr z, .withByte
ld a, (ix+2) ; second argspec ld a, (ix+2) ; second argspec
ld hl, curArg2 ld hl, INS_CURARG2
call checkNOrM call checkNOrM
jr z, .withWord jr z, .withWord
call checknmxy call checknmxy
@ -823,18 +832,18 @@ parseInstruction:
; Let's keep a copy in a more cosy register. ; Let's keep a copy in a more cosy register.
ld c, a ld c, a
xor a xor a
ld (curArg1), a ld (INS_CURARG1), a
ld (curArg2), a ld (INS_CURARG2), a
call readWord call readWord
jr nz, .nomorearg jr nz, .nomorearg
ld de, curArg1 ld de, INS_CURARG1
call processArg call processArg
jr nz, .error ; A is set to error jr nz, .error ; A is set to error
call readComma call readComma
jr nz, .nomorearg jr nz, .nomorearg
call readWord call readWord
jr nz, .badfmt jr nz, .badfmt
ld de, curArg2 ld de, INS_CURARG2
call processArg call processArg
jr nz, .error ; A is set to error jr nz, .error ; A is set to error
.nomorearg: .nomorearg:
@ -858,7 +867,7 @@ parseInstruction:
or a ; is zero? or a ; is zero?
jr z, .overflow jr z, .overflow
ld b, a ; save output byte count ld b, a ; save output byte count
ld hl, instrUpcode ld hl, INS_UPCODE
.loopWrite: .loopWrite:
ld a, (hl) ld a, (hl)
call ioPutC call ioPutC
@ -1206,15 +1215,3 @@ instrTBl:
.db I_XOR, 'l', 0, 0, 0xae , 0 ; XOR (HL) .db I_XOR, 'l', 0, 0, 0xae , 0 ; XOR (HL)
.db I_XOR, 0xb, 0, 0, 0b10101000 , 0 ; XOR r .db I_XOR, 0xb, 0, 0, 0b10101000 , 0 ; XOR r
.db I_XOR, 'n', 0, 0, 0xee , 0 ; XOR n .db I_XOR, 'n', 0, 0, 0xee , 0 ; XOR n
; *** Variables ***
; Args are 3 bytes: argspec, then values of numerical constants (when that's
; appropriate)
curArg1:
.db 0, 0, 0
curArg2:
.db 0, 0, 0
instrUpcode:
.db 0, 0, 0, 0

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