;
- .export _lseek
- .import incsp6,__oserror
- .import __inviocb,ldax0sp,ldaxysp,fdtoiocb
- .import __dos_type
- .import fd_table
- .importzp sreg,ptr1,ptr2,ptr3,ptr4
- .importzp tmp1,tmp2,tmp3
- .include "atari.inc"
- .include "errno.inc"
- .include "fd.inc"
+ .export _lseek
+ .import incsp6,__oserror
+ .import __inviocb,ldax0sp,ldaxysp,fdtoiocb
+ .import __dos_type
+ .import fd_table
+ .importzp sreg,ptr1,ptr2,ptr3,ptr4
+ .importzp tmp1,tmp2,tmp3
+ .include "atari.inc"
+ .include "errno.inc"
+ .include "fd.inc"
; seeking not supported, return -1 and ENOSYS errno value
-no_supp:jsr incsp6
- lda #<ENOSYS
- jsr __directerrno ; returns with $FFFF in AX
- sta sreg
- sta sreg+1
- rts
+no_supp:jsr incsp6
+ lda #<ENOSYS
+ jsr __directerrno ; returns with $FFFF in AX
+ sta sreg
+ sta sreg+1
+ rts
parmerr:
-iocberr:jsr incsp6
- ldx #255
- stx sreg
- stx sreg+1
- jmp __inviocb
+iocberr:jsr incsp6
+ ldx #255
+ stx sreg
+ stx sreg+1
+ jmp __inviocb
; lseek() entry point
-.proc _lseek
+.proc _lseek
- cpx #0 ; sanity check whence parameter
- bne parmerr
- cmp #3 ; valid values are 0..2
- bcs parmerr
- sta tmp1 ; remember whence
+ cpx #0 ; sanity check whence parameter
+ bne parmerr
+ cmp #3 ; valid values are 0..2
+ bcs parmerr
+ sta tmp1 ; remember whence
- ldy #5
- jsr ldaxysp ; get fd
- jsr fdtoiocb ; convert to iocb in A, fd_table index in X
- bmi iocberr
- sta tmp3 ; remember iocb
+ ldy #5
+ jsr ldaxysp ; get fd
+ jsr fdtoiocb ; convert to iocb in A, fd_table index in X
+ bmi iocberr
+ sta tmp3 ; remember iocb
- jsr chk_supp ; check, whether seeking is supported by DOS/Disk
- bcc no_supp
+ jsr chk_supp ; check, whether seeking is supported by DOS/Disk
+ bcc no_supp
- ldx tmp1 ; whence
- beq cur
- dex
- beq end
+ ldx tmp1 ; whence
+ beq cur
+ dex
+ beq end
; SEEK_SET
- dex
- stx ptr3
- stx ptr3+1
- stx ptr4
- stx ptr4+1
- beq cont
+ dex
+ stx ptr3
+ stx ptr3+1
+ stx ptr4
+ stx ptr4+1
+ beq cont
; SEEK_CUR
-cur: ldx tmp3
- lda #38 ; NOTE
- sta ICCOM,x
- jsr CIOV ; read it
- bmi xxerr
-l01: lda ICAX3,x ; low byte of position
- sta ptr3
- lda ICAX4,x ; med byte of position
- sta ptr3+1
- lda ICAX5,x ; high byte of position
- sta ptr4
- lda #0
- sta ptr4+1
- beq cont
+cur: ldx tmp3
+ lda #38 ; NOTE
+ sta ICCOM,x
+ jsr CIOV ; read it
+ bmi xxerr
+l01: lda ICAX3,x ; low byte of position
+ sta ptr3
+ lda ICAX4,x ; med byte of position
+ sta ptr3+1
+ lda ICAX5,x ; high byte of position
+ sta ptr4
+ lda #0
+ sta ptr4+1
+ beq cont
; SEEK_END
-end: ldx tmp3
- lda #39 ; get file size
- sta ICCOM,x
- jsr CIOV
- bpl l01
+end: ldx tmp3
+ lda #39 ; get file size
+ sta ICCOM,x
+ jsr CIOV
+ bpl l01
; error returned from CIO
-xxerr: tya
- pha
- jsr incsp6
- pla
- jsr __mappederrno ; returns with $FFFF in AX
- sta sreg
- sta sreg+1
- rts
+xxerr: tya
+ pha
+ jsr incsp6
+ pla
+ jsr __mappederrno ; returns with $FFFF in AX
+ sta sreg
+ sta sreg+1
+ rts
; check for offset 0, SEEK_CUR (get current position)
-cont: ldy #3
- jsr ldaxysp ; get upper word
- sta ptr1
- stx ptr1+1
- jsr ldax0sp ; get lower word
- stx tmp2
- ora tmp2
- ora ptr1
- ora ptr1+1
- bne seek
- lda tmp1 ; whence (0 = SEEK_CUR)
- bne seek
+cont: ldy #3
+ jsr ldaxysp ; get upper word
+ sta ptr1
+ stx ptr1+1
+ jsr ldax0sp ; get lower word
+ stx tmp2
+ ora tmp2
+ ora ptr1
+ ora ptr1+1
+ bne seek
+ lda tmp1 ; whence (0 = SEEK_CUR)
+ bne seek
; offset 0, SEEK_CUR: return current fp
-ret: jsr incsp6
+ret: jsr incsp6
- lda ptr4+1
- sta sreg+1
- lda ptr4
- sta sreg
- ldx ptr3+1
- lda ptr3
+ lda ptr4+1
+ sta sreg+1
+ lda ptr4
+ sta sreg
+ ldx ptr3+1
+ lda ptr3
.if 0
- ; return exactly the position DOS has
- ldx tmp3
- lda #38 ; NOTE
- sta ICCOM,x
- jsr CIOV ; read it
- bmi xxerr
- lda #0
- sta sreg+1
- lda ICAX5,x ; high byte of position
- sta sreg
- lda ICAX3,x ; low byte of position
- pha
- lda ICAX4,x ; med byte of position
- tax
- pla
+ ; return exactly the position DOS has
+ ldx tmp3
+ lda #38 ; NOTE
+ sta ICCOM,x
+ jsr CIOV ; read it
+ bmi xxerr
+ lda #0
+ sta sreg+1
+ lda ICAX5,x ; high byte of position
+ sta sreg
+ lda ICAX3,x ; low byte of position
+ pha
+ lda ICAX4,x ; med byte of position
+ tax
+ pla
.endif
- rts
+ rts
-parmerr1: jmp parmerr
+parmerr1: jmp parmerr
; we have to call POINT
-seek: jsr ldax0sp ; get lower word of new offset
- clc
- adc ptr3
- sta ptr3
- txa
- adc ptr3+1
- sta ptr3+1
- lda ptr1
- adc ptr4
- sta ptr4
- lda ptr1+1
- adc ptr4+1
- sta ptr4+1
- bne parmerr1 ; resulting value too large
-
- ldx tmp3 ; IOCB
- lda ptr3
- sta ICAX3,x
- lda ptr3+1
- sta ICAX4,x
- lda ptr4
- sta ICAX5,x
- lda #37 ;POINT
- sta ICCOM,x
- jsr CIOV
- bpl ret
- bmi xxerr
+seek: jsr ldax0sp ; get lower word of new offset
+ clc
+ adc ptr3
+ sta ptr3
+ txa
+ adc ptr3+1
+ sta ptr3+1
+ lda ptr1
+ adc ptr4
+ sta ptr4
+ lda ptr1+1
+ adc ptr4+1
+ sta ptr4+1
+ bne parmerr1 ; resulting value too large
+
+ ldx tmp3 ; IOCB
+ lda ptr3
+ sta ICAX3,x
+ lda ptr3+1
+ sta ICAX4,x
+ lda ptr4
+ sta ICAX5,x
+ lda #37 ;POINT
+ sta ICCOM,x
+ jsr CIOV
+ bpl ret
+ bmi xxerr
.endproc
; check, whether seeking is supported
-; tmp3: iocb
-; X: index into fd_table
+; tmp3: iocb
+; X: index into fd_table
;
; On non-SpartaDOS, seeking is not supported.
; We check, whether CIO function 39 (get file size) returns OK.
; We remember a successful check in fd_table.ft_flag, bit 3.
chk_supp:
- lda fd_table+ft_flag,x
- and #8
- bne supp
+ lda fd_table+ft_flag,x
+ and #8
+ bne supp
; do the test
- lda __dos_type
- cmp #SPARTADOS
- bne ns1
- txa
- pha
- lda DOS+1 ; get SpartaDOS version
- cmp #$40
- bcs supp1 ; SD-X (ver 4.xx) supports seeking on all disks
- ldx tmp3 ; iocb to use
- lda #39 ; get file size
- sta ICCOM,x
- jsr CIOV
- bmi notsupp ; error code ? should be 168 (invalid command)
+ lda __dos_type
+ cmp #SPARTADOS
+ bne ns1
+ txa
+ pha
+ lda DOS+1 ; get SpartaDOS version
+ cmp #$40
+ bcs supp1 ; SD-X (ver 4.xx) supports seeking on all disks
+ ldx tmp3 ; iocb to use
+ lda #39 ; get file size
+ sta ICCOM,x
+ jsr CIOV
+ bmi notsupp ; error code ? should be 168 (invalid command)
; seeking is supported on this DOS/Disk combination
-supp1: pla
- tax
- lda #8
- ora fd_table+ft_flag,x
- sta fd_table+ft_flag,x
-supp: sec
- rts
+supp1: pla
+ tax
+ lda #8
+ ora fd_table+ft_flag,x
+ sta fd_table+ft_flag,x
+supp: sec
+ rts
notsupp:pla
-ns1: clc
- rts
+ns1: clc
+ rts
projects / cc65 / blobdiff