collapseos/apps/zasm/main.asm

71 lines
1.1 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
or a ; is zero? stop
jr z, .stop
add a, c
ld c, a
call gotoNextLine
jr nz, .stop ; error? stop
jr .loop
.stop:
ret
#include "util.asm"
#include "tok.asm"
#include "instr.asm"
#include "directive.asm"
; Parse line in (HL), write the resulting opcode(s) in (DE) and returns the
; number of written bytes in A. Advances HL where tokenization stopped and DE
; to where we should write the next upcode.
parseLine:
push bc
call gotoNextNotBlankLine
jr nz, .error
push de
ld de, token
call tokenize
pop de
ld a, (token) ; TOK_*
cp TOK_BAD
jr z, .error
cp TOK_INSTR
jr z, .instr
jr .error ; directive not supported yet
.instr:
ld a, (token+1) ; I_*
call parseInstruction
or a ; is zero?
jr z, .error
ld b, 0
ld c, a ; written bytes
push hl
ld hl, curUpcode
call copy
pop hl
call JUMP_ADDDE
jr .end
.error:
xor a
.end:
pop bc
ret
; *** Variables ***
token:
.fill 5
scratchpad:
.fill 0x20