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cc65/libsrc/atari/open.s
cuz bfdfd83fde __seterrno is now a common function available on all platforms with slightly
different calling conventions.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3038 b7a2c559-68d2-44c3-8de9-860c34a00d81
2004-05-13 21:56:31 +00:00

172 lines
2.5 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"
.export _open
.destructor closeallfiles, 17
.import _close
.import clriocb
.import fddecusage,newfd
.import findfreeiocb
.import __do_oserror,incsp4
.import ldaxysp,addysp
.import __oserror
.importzp tmp4,tmp2
.ifdef UCASE_FILENAME
.importzp tmp3
.import ucase_fn
.endif
.proc _open
cpy #4 ; correct # of arguments (bytes)?
beq parmok ; parameter count ok
tya ; parm count < 4 shouldn't be needed to be checked
sec ; (it generates a c compiler warning)
sbc #4
tay
jsr addysp ; fix stack, throw away unused parameters
parmok: jsr findfreeiocb
beq iocbok ; we found one
lda #<EMFILE ; "too many open files"
seterr: jsr __seterrno
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
ldx #>EINVAL
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
jsr ucase_fn
bcc ucok1
invret: lda #<EINVAL ; file name is too long
ldx #>EINVAL
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
jsr fddecusage ; decrement usage counter of fd as open failed
jmp __do_oserror
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