mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 15:29:46 +00:00
145 lines
2.7 KiB
ArmAsm
145 lines
2.7 KiB
ArmAsm
;
|
|
; Karri Kaksonen, 2010
|
|
;
|
|
; This function reads the directory entry for file "name".
|
|
;
|
|
; The name is actually plain ASCII string starting from
|
|
; "0", "1", up to "4095" which is the largest file number we can handle.
|
|
;
|
|
; open() does not take part in what kind of cart we have. If it is RAM
|
|
; you may also be able to write into it. Therefore we allow both reads
|
|
; and writes in this routine.
|
|
;
|
|
; int open(const char *name, int flags, ...)
|
|
;
|
|
; As helper functions we also provide.
|
|
; void openn(int fileno)
|
|
;
|
|
.importzp sreg, tmp3
|
|
.macpack longbranch
|
|
.import _atoi
|
|
.import _read
|
|
.import _lseek
|
|
.import addysp,popax,pushax,decsp6,pusha0,pusheax,ldaxysp
|
|
.import aslax3,axlong,tosaddeax,steaxysp,stax0sp,incsp8
|
|
.import ldax0sp
|
|
.import lynxskip0, lynxblock
|
|
.importzp _FileEntry
|
|
.importzp _FileStartBlock
|
|
.importzp _FileCurrBlock
|
|
.importzp _FileBlockOffset
|
|
.import __STARTOFDIRECTORY__
|
|
.export _open
|
|
.export _openn
|
|
|
|
.include "errno.inc"
|
|
.include "fcntl.inc"
|
|
|
|
.segment "DATA"
|
|
|
|
_startofdirectory:
|
|
.dword __STARTOFDIRECTORY__
|
|
|
|
; ---------------------------------------------------------------
|
|
; int __near__ open (__near__ const unsigned char*, int)
|
|
; ---------------------------------------------------------------
|
|
|
|
.segment "CODE"
|
|
|
|
.proc _open
|
|
|
|
.segment "CODE"
|
|
|
|
dey
|
|
dey
|
|
dey
|
|
dey
|
|
beq parmok
|
|
jsr addysp
|
|
|
|
parmok: jsr popax
|
|
sta tmp3
|
|
and #(O_RDWR | O_CREAT)
|
|
cmp #O_RDONLY
|
|
beq flagsok
|
|
cmp #(O_WRONLY | O_CREAT)
|
|
beq flagsok
|
|
jsr popax
|
|
lda #EINVAL
|
|
jmp __directerrno
|
|
|
|
flagsok:
|
|
jsr popax
|
|
jsr _atoi
|
|
jsr _openn
|
|
ldx #$00
|
|
lda #$01
|
|
stx __oserror
|
|
rts
|
|
|
|
.endproc
|
|
|
|
; ---------------------------------------------------------------
|
|
; void __near__ __fastcall__ openn (int)
|
|
; ---------------------------------------------------------------
|
|
|
|
.segment "CODE"
|
|
|
|
.proc _openn: near
|
|
|
|
.segment "CODE"
|
|
|
|
jsr pushax
|
|
jsr decsp6
|
|
lda #$01
|
|
jsr pusha0
|
|
lda _startofdirectory+3
|
|
sta sreg+1
|
|
lda _startofdirectory+2
|
|
sta sreg
|
|
ldx _startofdirectory+1
|
|
lda _startofdirectory
|
|
jsr pusheax
|
|
ldy #$0D
|
|
jsr ldaxysp
|
|
jsr aslax3
|
|
jsr axlong
|
|
jsr tosaddeax
|
|
jsr pusheax
|
|
ldx #$00
|
|
txa
|
|
jsr _lseek
|
|
ldy #$02
|
|
jsr steaxysp
|
|
lda #$01
|
|
jsr pusha0
|
|
lda #<_FileEntry
|
|
ldx #>_FileEntry
|
|
jsr pushax
|
|
ldx #$00
|
|
lda #$08
|
|
jsr _read
|
|
lda _FileStartBlock
|
|
sta _FileCurrBlock
|
|
jsr lynxblock
|
|
lda _FileBlockOffset
|
|
ldx _FileBlockOffset+1
|
|
phx ; The BLL kit uses negative offsets
|
|
plx ; while tha basic Lynx uses positive
|
|
bmi @1 ; Make all offsets negative
|
|
eor #$FF
|
|
pha
|
|
txa
|
|
eor #$FF
|
|
bra @2
|
|
@1: pha
|
|
txa
|
|
@2: tay
|
|
plx
|
|
jsr lynxskip0
|
|
jsr stax0sp
|
|
jmp incsp8
|
|
|
|
.endproc
|
|
|