;
; only ONE opened file at a time, only O_RDONLY flag
-; int open (const char* name, int flags, ...); /* May take a mode argument */
+; int open (const char* name, int flags, ...); /* May take a mode argument */
; int __fastcall__ close (int fd);
; int __fastcall__ read (int fd, void* buf, unsigned count);
-FILEDES = 3 ; first free to use file descriptor
+FILEDES = 3 ; first free to use file descriptor
.importzp ptr1, ptr2, ptr3, tmp1
.import addysp, popax
.import __oserror
- .import _FindFile, _ReadByte
- .export _open, _close, _read
+ .import _FindFile, _ReadByte
+ .export _open, _close, _read
- .include "geossym.inc"
- .include "const.inc"
- .include "errno.inc"
- .include "fcntl.inc"
+ .include "geossym.inc"
+ .include "const.inc"
+ .include "errno.inc"
+ .include "fcntl.inc"
_open:
- cpy #4 ; correct # of arguments (bytes)?
- beq @parmok ; parameter count ok
- tya ; parm count < 4 shouldn't be needed to be...
- sec ; ...checked (it generates a c compiler warning)
- sbc #4
- tay
- jsr addysp ; fix stack, throw away unused parameters
+ cpy #4 ; correct # of arguments (bytes)?
+ beq @parmok ; parameter count ok
+ tya ; parm count < 4 shouldn't be needed to be...
+ sec ; ...checked (it generates a c compiler warning)
+ sbc #4
+ tay
+ jsr addysp ; fix stack, throw away unused parameters
; Parameters ok. Pop the flags and save them into tmp3
@parmok:
- jsr popax ; Get flags
- sta tmp1
- jsr popax ; Get name
- sta ptr1
- stx ptr1+1
-
- lda filedesc ; is there a file already open?
- bne @alreadyopen
-
- lda tmp1 ; check open mode
- and #(O_RDWR | O_CREAT)
- cmp #O_RDONLY ; only O_RDONLY is valid
- bne @badmode
-
- lda ptr1
- ldx ptr1+1
- jsr _FindFile ; try to find the file
- tax
- bne @oserror
-
- lda dirEntryBuf + OFF_DE_TR_SC ; tr&se for ReadByte (r1)
- sta f_track
- lda dirEntryBuf + OFF_DE_TR_SC + 1
- sta f_sector
- lda #<diskBlkBuf ; buffer for ReadByte (r4)
- sta f_buffer
- lda #>diskBlkBuf
- sta f_buffer+1
- ldx #0 ; offset for ReadByte (r5)
- stx f_offset
- stx f_offset+1
- lda #0 ; clear errors
- sta __oserror
- jsr __seterrno
- lda #FILEDES ; return fd
- sta filedesc
- rts
+ jsr popax ; Get flags
+ sta tmp1
+ jsr popax ; Get name
+ sta ptr1
+ stx ptr1+1
+
+ lda filedesc ; is there a file already open?
+ bne @alreadyopen
+
+ lda tmp1 ; check open mode
+ and #(O_RDWR | O_CREAT)
+ cmp #O_RDONLY ; only O_RDONLY is valid
+ bne @badmode
+
+ lda ptr1
+ ldx ptr1+1
+ jsr _FindFile ; try to find the file
+ tax
+ bne @oserror
+
+ lda dirEntryBuf + OFF_DE_TR_SC ; tr&se for ReadByte (r1)
+ sta f_track
+ lda dirEntryBuf + OFF_DE_TR_SC + 1
+ sta f_sector
+ lda #<diskBlkBuf ; buffer for ReadByte (r4)
+ sta f_buffer
+ lda #>diskBlkBuf
+ sta f_buffer+1
+ ldx #0 ; offset for ReadByte (r5)
+ stx f_offset
+ stx f_offset+1
+ lda #0 ; clear errors
+ sta __oserror
+ jsr __seterrno
+ lda #FILEDES ; return fd
+ sta filedesc
+ rts
@badmode:
- lda #EINVAL ; invalid parameters - invalid open mode
- .byte $2c ; skip
+ lda #EINVAL ; invalid parameters - invalid open mode
+ .byte $2c ; skip
@alreadyopen:
- lda #EMFILE ; too many opened files (there can be only one)
- jmp __directerrno ; set errno, clear oserror, return -1
+ lda #EMFILE ; too many opened files (there can be only one)
+ jmp __directerrno ; set errno, clear oserror, return -1
@oserror:
- jmp __mappederrno ; set platform error code, return -1
+ jmp __mappederrno ; set platform error code, return -1
_close:
- lda #0
- sta __oserror
- jsr __seterrno ; clear errors
- lda #0 ; clear fd
- sta filedesc
- tax
- rts
+ lda #0
+ sta __oserror
+ jsr __seterrno ; clear errors
+ lda #0 ; clear fd
+ sta filedesc
+ tax
+ rts
_read:
; a/x - number of bytes
; popax - fd, must be == to the above one
; return -1+__oserror or number of bytes read
- eor #$ff
- sta ptr1
- txa
- eor #$ff
- sta ptr1+1 ; -(# of bytes to read)-1
- jsr popax
- sta ptr2
- stx ptr2+1 ; buffer ptr
- jsr popax
- cmp #FILEDES ; lo-byte == FILEDES
- bne @filenotopen
- txa ; hi-byte == 0
- beq @fileok ; fd must be == FILEDES
+ eor #$ff
+ sta ptr1
+ txa
+ eor #$ff
+ sta ptr1+1 ; -(# of bytes to read)-1
+ jsr popax
+ sta ptr2
+ stx ptr2+1 ; buffer ptr
+ jsr popax
+ cmp #FILEDES ; lo-byte == FILEDES
+ bne @filenotopen
+ txa ; hi-byte == 0
+ beq @fileok ; fd must be == FILEDES
@filenotopen:
- lda #EBADF
- jmp __directerrno ; Sets _errno, clears _oserror, returns -1
+ lda #EBADF
+ jmp __directerrno ; Sets _errno, clears _oserror, returns -1
@fileok:
- lda #0
- sta ptr3
- sta ptr3+1 ; put 0 into ptr3 (number of bytes read)
- sta __oserror ; clear error flags
- jsr __seterrno
-
- lda f_track ; restore stuff for ReadByte
- ldx f_sector
- sta r1L
- stx r1H
- lda f_buffer
- ldx f_buffer+1
- sta r4L
- stx r4H
- lda f_offset
- ldx f_offset+1
- sta r5L
- stx r5H
-
- clc
- bcc @L3 ; branch always
-
-@L0: jsr _ReadByte
- ldy #0 ; store the byte
- sta (ptr2),y
- inc ptr2 ; increment target address
- bne @L1
- inc ptr2+1
-
-@L1: inc ptr3 ; increment byte count
- bne @L2
- inc ptr3+1
-
-@L2: lda __oserror ; was there error ?
- beq @L3
- cmp #BFR_OVERFLOW ; EOF?
- beq @done ; yes, we're done
- jmp __mappederrno ; no, we're screwed
-
-@L3: inc ptr1 ; decrement the count
- bne @L0
- inc ptr1+1
- bne @L0
+ lda #0
+ sta ptr3
+ sta ptr3+1 ; put 0 into ptr3 (number of bytes read)
+ sta __oserror ; clear error flags
+ jsr __seterrno
+
+ lda f_track ; restore stuff for ReadByte
+ ldx f_sector
+ sta r1L
+ stx r1H
+ lda f_buffer
+ ldx f_buffer+1
+ sta r4L
+ stx r4H
+ lda f_offset
+ ldx f_offset+1
+ sta r5L
+ stx r5H
+
+ clc
+ bcc @L3 ; branch always
+
+@L0: jsr _ReadByte
+ ldy #0 ; store the byte
+ sta (ptr2),y
+ inc ptr2 ; increment target address
+ bne @L1
+ inc ptr2+1
+
+@L1: inc ptr3 ; increment byte count
+ bne @L2
+ inc ptr3+1
+
+@L2: lda __oserror ; was there error ?
+ beq @L3
+ cmp #BFR_OVERFLOW ; EOF?
+ beq @done ; yes, we're done
+ jmp __mappederrno ; no, we're screwed
+
+@L3: inc ptr1 ; decrement the count
+ bne @L0
+ inc ptr1+1
+ bne @L0
@done:
- lda r1L ; preserve data for ReadByte
- ldx r1H
- sta f_track
- stx f_sector
- lda r4L
- ldx r4H
- sta f_buffer
- stx f_buffer+1
- lda r5L
- ldx r5H
- sta f_offset
- stx f_offset+1
-
- lda ptr3 ; return byte count
- ldx ptr3+1
- rts
+ lda r1L ; preserve data for ReadByte
+ ldx r1H
+ sta f_track
+ stx f_sector
+ lda r4L
+ ldx r4H
+ sta f_buffer
+ stx f_buffer+1
+ lda r5L
+ ldx r5H
+ sta f_offset
+ stx f_offset+1
+
+ lda ptr3 ; return byte count
+ ldx ptr3+1
+ rts
.bss
filedesc:
- .res 1 ; file open flag - 0 (no file opened) or 1
+ .res 1 ; file open flag - 0 (no file opened) or 1
f_track:
- .res 1 ; values preserved for ReadByte
+ .res 1 ; values preserved for ReadByte
f_sector:
- .res 1
+ .res 1
f_offset:
- .res 2
+ .res 2
f_buffer:
- .res 2
+ .res 2
projects / cc65 / blobdiff