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Working on the CBM file functions

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git-svn-id: svn://svn.cc65.org/cc65/trunk@1533 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz
2002-11-17 22:45:55 +00:00
parent 43d5800702
commit 544ff5b900
11 changed files with 377 additions and 229 deletions
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78
libsrc/cbm/read.s
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@@ -6,10 +6,11 @@
.export _read
.constructor initstdin
.import rwcommon
.import popax
.import __errno, __oserror
.importzp ptr1, ptr2, ptr3, tmp1, tmp2
.importzp ptr1, ptr2, ptr3, tmp1, tmp2, tmp3
.include "errno.inc"
.include "fcntl.inc"
@@ -39,31 +40,8 @@
.proc _read
; Retrieve count
jsr popax ; Get count
eor #$FF
sta ptr1
txa
eor #$FF
sta ptr1+1 ; Remember -count-1
; Retrieve buf
jsr popax
sta ptr2
stx ptr2+1
; Retrieve the handle
jsr popax
; Check if we have a valid handle
cpx #$00
bne invalidfd
cmp #MAX_FDS ; Is it valid?
bcs invalidfd ; Jump if no
jsr rwcommon ; Pop params, check handle
bcs invalidfd ; Branch if handle not ok
; Check if the LFN is valid and the file is open for writing
@@ -73,34 +51,27 @@
and #LFN_READ ; File open for writing?
beq notopen
; Check the EOF flag. If it is set, don't read anything
lda fdtab-LFN_OFFS,x; Get flags for this handle
bmi eof
; Valid lfn. Make it the input file
jsr CHKIN
bcs error
; Clear the byte counter
lda #$00
sta ptr3
sta ptr3+1
; Read the status to check if we are already at the end of the file
jsr READST
and #%01000000
bne done
; Go looping...
beq deccount ; Branch always
bcc @L3 ; Branch always
; Read the next byte
loop: jsr BASIN
@L0: jsr BASIN
sta tmp1 ; Save the input byte
jsr READST ; Read the IEEE status
sta tmp2 ; Save it
sta tmp3 ; Save it
and #%10111111 ; Check anything but the EOI bit
bne error5 ; Assume device not present
@@ -121,17 +92,24 @@ loop: jsr BASIN
; Get the status again and check the EOI bit
@L2: lda tmp2
@L2: lda tmp3
and #%01000000 ; Check for EOI
bne done ; Jump if end of file reached
bne @L4 ; Jump if end of file reached
; Decrement the count
deccount:
inc ptr1
bne loop
@L3: inc ptr1
bne @L0
inc ptr1+1
bne loop
bne @L0
beq done ; Branch always
; Set the EOI flag and bail out
@L4: ldx tmp2 ; Get the handle
lda #LFN_EOF
ora fdtab,x
sta fdtab,x
; Read done, close the input channel
@@ -139,7 +117,7 @@ done: jsr CLRCH
; Return the number of chars read
lda ptr3
eof: lda ptr3
ldx ptr3+1
rts
@@ -157,7 +135,7 @@ invalidfd:
notopen:
lda #3 ; File not open
bne error
; Error entry, status not ok
error5: lda #5 ; Device not present