cc65/libsrc/telestrat/write.s

88 lines
1.8 KiB
ArmAsm

;
; jede jede@oric.org 2017-01-22
.export _write
.import popax, popptr1
.include "zeropage.inc"
.include "telestrat.inc"
; int write (int fd, const void* buf, int count);
.proc _write
sta ptr3
stx ptr3+1 ; save count as result
inx
stx ptr2+1
tax
inx
stx ptr2 ; save count with each byte incremented separately
jsr popptr1 ; get buf
jsr popax ; get fd
sta tmp1 ; save fd
; if fd=0001 then it stdout
cpx #0
beq next
jmp L1
next:
cmp #1
beq L1
; here it's a file opened
lda ptr1
sta PTR_READ_DEST
lda ptr1+1
sta PTR_READ_DEST+1
lda ptr3
ldy ptr3+1
ldx tmp1 ; send fd in X
BRK_TELEMON XFWRITE
; compute nb of bytes written
sec
lda PTR_READ_DEST
sbc ptr1
pha
lda PTR_READ_DEST+1
sbc ptr1+1
tax
pla
rts
L1: dec ptr2
bne L2
dec ptr2+1
beq L9
L2: ldy #0
lda (ptr1),y
tax
cpx #$0A ; check for \n
bne L3
BRK_TELEMON XWR0 ; macro send char to screen (channel 0 in telemon terms)
lda #$0D ; return to the beggining of the line
BRK_TELEMON XWR0 ; macro
ldx #$0D
L3:
BRK_TELEMON XWR0 ; macro
inc ptr1
bne L1
inc ptr1+1
jmp L1
; no error, return count
L9: lda ptr3
ldx ptr3+1
rts
.endproc