;
-; Ullrich von Bassewitz, 16.11.2002
+; 2002-11-16, Ullrich von Bassewitz
+; 2013-12-23, Greg King
;
; int read (int fd, void* buf, unsigned count);
;
.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 "cbm.inc"
.include "errno.inc"
.include "fcntl.inc"
- .include "cbm.inc"
.include "filedes.inc"
;--------------------------------------------------------------------------
; initstdin: Open the stdin file descriptors for the keyboard
+.segment "ONCE"
+
.proc initstdin
- lda #LFN_READ
- sta fdtab+STDIN_FILENO
lda #STDIN_FILENO + LFN_OFFS
ldx #CBMDEV_KBD
- stx unittab+STDIN_FILENO
ldy #$FF
jsr SETLFS
jmp OPEN ; Will always succeed
;--------------------------------------------------------------------------
; _read
+.code
.proc _read
-; Retrieve count
-
- jsr popax ; Get count
- eor #$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 ; Invalid handle
; Check if the LFN is valid and the file is open for writing
adc #LFN_OFFS ; Carry is already clear
tax
lda fdtab-LFN_OFFS,x; Get flags for this handle
+ tay
and #LFN_READ ; File open for writing?
- beq notopen
+ beq invalidfd
-; Valid lfn. Make it the input file
-
- jsr CHKIN
- bcs error
+; Check the EOF flag. If it is set, don't read anything
-; Clear the byte counter
+ tya ; Get flags again
+ bmi eof
- lda #$00
- sta ptr3
- sta ptr3+1
+; Remember the device number.
-; Read the status to check if we are already at the end of the file
-
- jsr READST
- and #%01000000
- bne done
+ ldy unittab-LFN_OFFS,x
+ sty unit
-; Go looping...
+; Valid lfn. Make it the input file
- beq deccount ; Branch always
+ jsr CHKIN
+ bcc @L3 ; Branch if ok
+ jmp __mappederrno ; Store into __oserror, map to errno, return -1
; 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
+ ldx unit
+ bne @L0_1 ; Not keyboard/screen-editor
+ cmp #$0D ; Is it a Carriage Return?
+ bne @L0_1
+ jsr BSOUT ; Yes, echo it (because editor didn't)
+
+@L0_1: jsr READST ; Read the IEEE status
+ sta tmp3 ; Save it
and #%10111111 ; Check anything but the EOI bit
- bne error5 ; Assume device not present
+ bne devnotpresent ; Assume device not present
; Store the byte just read
ldy #0
lda tmp1
- sta (ptr2),y
- inc ptr2
+ sta (ptr1),y
+ inc ptr1
bne @L1
- inc ptr2+1 ; *buf++ = A;
+ inc ptr1+1 ; *buf++ = A;
; Increment the byte count
; Get the status again and check the EOI bit
-@L2: lda tmp2
+@L2: lda tmp3
and #%01000000 ; Check for EOI
- bne done ; Jump if end of file reached
+ bne @L4 ; Jump if end of file reached
; Decrement the count
-deccount:
- inc ptr1
- bne loop
- inc ptr1+1
- bne loop
+@L3: inc ptr2
+ bne @L0
+ inc ptr2+1
+ bne @L0
+ beq done ; Branch always
+
+; Set the EOI flag and bail out
+
+@L4: ldx tmp2 ; Get the handle
+ lda #LFN_EOF
+ ora fdtab,x
+ sta fdtab,x
; Read done, close the input channel
done: jsr CLRCH
-; Return the number of chars read
+; Clear _oserror and return the number of chars read
+eof: lda #0
+ sta __oserror
lda ptr3
ldx ptr3+1
rts
-; Error entry, file descriptor is invalid
+; Error entry: Device not present
-invalidfd:
- lda #EINVAL
- sta __errno
- lda #0
- sta __errno+1
- beq errout
-
-; Error entry, file is not open
-
-notopen:
- lda #3 ; File not open
- bne error
+devnotpresent:
+ lda #ENODEV
+ jmp __directerrno ; Sets _errno, clears _oserror, returns -1
-; Error entry, status not ok
+; Error entry: The given file descriptor is not valid or not open
-error5: lda #5 ; Device not present
-error: sta __oserror
-errout: lda #$FF
- tax ; Return -1
- rts
+invalidfd:
+ lda #EBADF
+ jmp __directerrno ; Sets _errno, clears _oserror, returns -1
.endproc
+;--------------------------------------------------------------------------
+.bss
+unit: .res 1