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cc65/libsrc/cbm/devicedir.s
2022-08-28 22:37:33 +02:00

64 lines
1.3 KiB
ArmAsm

;
; Oliver Schmidt, 2012-09-10
;
; char* __fastcall__ getdevicedir (unsigned char device, char* buf, size_t size);
;
.export _getdevicedir
.import diskinit, devicestr, fnunit
.import popa, popax
.importzp ptr2, ptr3
.include "errno.inc"
;------------------------------------------------------------------------------
; _getdevicedir
.proc _getdevicedir
; Save size
sta ptr3
stx ptr3+1
; Save buf
jsr popax
sta ptr2
stx ptr2+1
; Check device readiness
jsr popa
jsr diskinit
beq size
jsr ___mappederrno
bne fail ; Branch always
; Check for sufficient buf size
size: lda ptr3+1
bne okay ; Buf >= 256
lda ptr3
cmp #3
bcs okay ; Buf >= 3
lda #<ERANGE
jsr ___directerrno
fail: lda #0 ; Return NULL
tax
rts
; Copy device string representation into buf
okay: lda fnunit ; Set by diskinit
jsr devicestr ; Returns 0 in A
sta ___oserror ; Clear __oserror
; Success, return buf
lda ptr2
ldx ptr2+1
rts
.endproc