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;
; Ullrich von Bassewitz, 16.11.2002
;
; int write (int fd, const void* buf, unsigned count);
;
.export _write
.constructor initstdout
.import rwcommon
.importzp sp, ptr1, ptr2, ptr3
.include "cbm.inc"
.include "errno.inc"
.include "fcntl.inc"
.include "filedes.inc"
;--------------------------------------------------------------------------
; initstdout: Open the stdout and stderr file descriptors for the screen.
.segment "ONCE"
.proc initstdout
lda #STDOUT_FILENO + LFN_OFFS
jsr @L1
lda #STDERR_FILENO + LFN_OFFS
@L1: ldx #CBMDEV_SCREEN
ldy #$FF
jsr SETLFS
jmp OPEN ; Will always succeed
.endproc
;--------------------------------------------------------------------------
; _write
.code
.proc _write
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
and #LFN_WRITE ; File open for writing?
beq invalidfd
; Valid lfn. Make it the output file
jsr CKOUT
bcc @L2
@error: jmp __mappederrno ; Store into __oserror, map to errno, return -1
; Output the next character from the buffer
@L0: ldy #0
lda (ptr1),y
inc ptr1
bne @L1
inc ptr1+1 ; A = *buf++;
@L1: jsr BSOUT
; Check the status
pha
jsr READST
lsr a ; Bit zero is write timeout
bne devnotpresent2
pla
bcs @L3
; Count characters written
inc ptr3
bne @L2
inc ptr3+1
; Decrement count
@L2: inc ptr2
bne @L0
inc ptr2+1
bne @L0
; Wrote all chars or disk full. Close the output channel
@L3: jsr CLRCH
; Clear _oserror and return the number of chars written
lda #0
sta __oserror
lda ptr3
ldx ptr3+1
rts
; Error entry: Device not present
devnotpresent2:
pla
devnotpresent:
lda #ENODEV
jmp __directerrno ; Sets _errno, clears _oserror, returns -1
; Error entry: The given file descriptor is not valid or not open
invalidfd:
lda #EBADF
jmp __directerrno ; Sets _errno, clears _oserror, returns -1
.endproc
|
