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collapseos/apps/zasm/main.asm
Virgil Dupras f9ae5ca46b zasm: simplify readWord calling
It always reads in the scratchpad with the same max size. No need for
DE-dancing anymore.
2019-05-01 14:19:43 -04:00

80 lines
1.3 KiB
NASM

#include "user.inc"
; *** Code ***
.org USER_CODE
; Parse asm file in (HL) and outputs its upcodes in (DE). Returns the number
; of bytes written in C.
main:
ld bc, 0 ; C is our written bytes counter
.loop:
call parseLine
jr nz, .stop
ld a, c
add a, ixl
ld c, a
call gotoNextLine
jr nz, .stop ; error? stop
jr .loop
.stop:
ret
#include "util.asm"
#include "parse.asm"
#include "literal.asm"
#include "instr.asm"
#include "tok.asm"
#include "directive.asm"
; Parse line in (HL), write the resulting opcode(s) in (DE) and returns the
; number of written bytes in IXL. Advances HL where tokenization stopped and DE
; to where we should write the next upcode.
; Sets Z if parse was successful, unset if there was an error or EOF.
parseLine:
push bc
call gotoNextNotBlankLine
jr nz, .error
call tokenize
ld a, b ; TOK_*
cp TOK_INSTR
jr z, .instr
cp TOK_DIRECTIVE
jr z, .direc
jr .error ; token not supported
.instr:
ld a, c ; I_*
call parseInstruction
or a ; is zero?
jr z, .error
ld b, 0
ld c, a ; written bytes
push hl
ld hl, instrUpcode
call copy
pop hl
call JUMP_ADDDE
jr .success
.direc:
ld a, c ; D_*
call parseDirective
ld b, 0
ld c, a ; written bytes
push hl
ld hl, direcData
call copy
pop hl
call JUMP_ADDDE
jr .success
.success:
ld ixl, a
xor a ; ensure Z
jr .end
.error:
xor ixl
call JUMP_UNSETZ
.end:
pop bc
ret