Files
cc65/libsrc/apple2/rwcommon.s
2025-11-02 21:24:59 +01:00

61 lines
1.5 KiB
ArmAsm

;
; Oliver Schmidt, 12.01.2005
;
.export rwprolog, rwcommon, rwepilog
.import popax, popptr1
.include "zeropage.inc"
.include "errno.inc"
.include "fcntl.inc"
.include "mli.inc"
.include "filedes.inc"
rwprolog:
; Save count
sta ptr2
stx ptr2+1
; Get and save buf
jsr popptr1
; Get and process fd
jsr popax
jmp getfd ; Returns A, Y and C
rwcommon:
; Set fd
sta mliparam + MLI::RW::REF_NUM
; Set buf and count
; buf (ptr1) goes to mliparam + MLI::RW::DATA_BUFFER,
; count (ptr2) goes to mliparam + MLI::RW::REQUEST_COUNT
; Make sure both are at expected offset so we can copy them
; in a small loop.
.assert ptr2 = ptr1 + 2, error
.assert MLI::RW::REQUEST_COUNT = MLI::RW::DATA_BUFFER + 2, error
ldx #$03
: lda ptr1,x
sta mliparam + MLI::RW::DATA_BUFFER,x
dex
bpl :-
; Call read or write
tya
ldx #RW_COUNT
jsr callmli
bcc rwepilog
cmp #$4C ; "End of file encountered"
bne oserr
rwepilog:
; Return success
sta ___oserror ; A = 0
lda mliparam + MLI::RW::TRANS_COUNT
ldx mliparam + MLI::RW::TRANS_COUNT+1
rts
; Set ___oserror
oserr: jmp ___mappederrno