cc65/libsrc/atari/open.s

178 lines
4.0 KiB
ArmAsm

;
; Christian Groessler, Jan-2003
;
; int open(const char *name,int flags,...);
;
.include "atari.inc"
.include "fcntl.inc"
.include "errno.inc"
.include "fd.inc"
.include "zeropage.inc"
.export _open
.destructor closeallfiles, 5
.import _close
.import clriocb
.import fddecusage,newfd
.import findfreeiocb
.import incsp4
.import ldaxysp,addysp
.import ___oserror
.ifdef UCASE_FILENAME
.import ucase_fn
.endif
.proc _open
dey ; parm count < 4 shouldn't be needed to be checked
dey ; (it generates a c compiler warning)
dey
dey
beq parmok ; parameter count ok
jsr addysp ; fix stack, throw away unused parameters
parmok: jsr findfreeiocb
beq iocbok ; we found one
lda #<EMFILE ; "too many open files"
seterr: jsr ___directerrno
jsr incsp4 ; clean up stack
lda #$FF
tax
rts ; return -1
; process the mode argument
iocbok: stx tmp4
jsr clriocb ; init with zero
ldy #1
jsr ldaxysp ; get mode
ldx tmp4
pha
and #O_APPEND
beq no_app
pla
and #15
cmp #O_RDONLY ; DOS supports append with write-only only
beq invret
cmp #O_RDWR
beq invret
lda #OPNOT|APPEND
bne set
.ifndef UCASE_FILENAME
invret: lda #<EINVAL ; file name is too long
jmp seterr
.endif
no_app: pla
and #15
cmp #O_RDONLY
bne l1
lda #OPNIN
set: sta ICAX1,x
bne cont
l1: cmp #O_WRONLY
bne l2
lda #OPNOT
bne set
l2: ; O_RDWR
lda #OPNOT|OPNIN
bne set
; process the filename argument
cont: ldy #3
jsr ldaxysp
.ifdef UCASE_FILENAME
.ifdef DEFAULT_DEVICE
ldy #$80
.else
ldy #$00
.endif
sty tmp2 ; set flag for ucase_fn
jsr ucase_fn
bcc ucok1
invret: lda #<EINVAL ; file name is too long
jmp seterr
ucok1:
.endif ; defined UCASE_FILENAME
ldy tmp4
;AX - points to filename
;Y - iocb to use, if open needed
jsr newfd ; maybe we don't need to open and can reuse an iocb
; returns fd num to use in tmp2, all regs unchanged
bcs doopen ; C set: open needed
lda #0 ; clears N flag
beq finish
doopen: sta ICBAL,y
txa
sta ICBAH,y
ldx tmp4
lda #OPEN
sta ICCOM,x
jsr CIOV
; clean up the stack
finish: php
txa
pha
tya
pha
.ifdef UCASE_FILENAME
ldy tmp3 ; get size
jsr addysp ; free used space on the stack
.endif ; defined UCASE_FILENAME
jsr incsp4 ; clean up stack
pla
tay
pla
tax
plp
bpl ok
sty tmp3 ; remember error code
lda #CLOSE
sta ICCOM,x
jsr CIOV ; close IOCB again since open failed
jsr fddecusage ; and decrement usage counter of fd
lda tmp3 ; put error code into A
jmp ___mappederrno
ok: lda tmp2 ; get fd
ldx #0
stx ___oserror
rts
.endproc
; closeallfiles: Close all files opened by the program.
.proc closeallfiles
lda #MAX_FD_INDEX-1
loop: ldx #0
pha
jsr _close
pla
clc
sbc #0
bpl loop
rts
.endproc