nes-proj/platform/apple2enh/lib/pfs.S
oliverschmidt 852d2c0283 Introduced very lightweight pfs implementation based on Apple ProDOS.
ProDOS requires for each opened file a user-supplied page-aligned 1024 byte i/o buffer. This makes the generic POSIX file i/o library contained in the cc65 C-library quite heavyweight.

In contrast the lightweight pfs implementation uses the uIP packet buffer as ProDOS i/o buffer. Therefore:
- Only one file may be open at any time.
- That file may not be open while the uIP packet buffer is used by uIP. The open()/read()/close() sequence should be completed before Contiki event scheduling or inside handling a single Contiki event.
- The uIP packet buffer must be large enough to hold the ProDOS I/O buffer. Depending on the position of the uIP buffer in memory this means between 1024 and 1024 + 256 bytes. Therefore in an Ethernet environment setting the MTU_SIZE to at least 1266 is safe (So the default of 1500 is just fine).
2008-01-01 18:49:50 +00:00

155 lines
3.8 KiB
ArmAsm

;
; Copyright (c) 2008, Swedish Institute of Computer Science.
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions
; are met:
; 1. Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
; 2. Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
; 3. Neither the name of the Institute nor the names of its contributors
; may be used to endorse or promote products derived from this software
; without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
; ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
; OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
; OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
; SUCH DAMAGE.
;
; This file is part of the Contiki operating system.
;
; Author: Oliver Schmidt <ol.sc@web.de>
;
; $Id: pfs.S,v 1.1 2008/01/01 18:49:51 oliverschmidt Exp $
;
;---------------------------------------------------------------------
.constructor init_pfs
.destructor done_pfs
.importzp ptr1
.import popax, _uip_buf
.export _pfs_open, _pfs_read, _pfs_close
;---------------------------------------------------------------------
pathname := $0280
mli := $BF00
OPEN_CALL = $C8
READ_CALL = $CA
CLOSE_CALL = $CC
;---------------------------------------------------------------------
.bss
prefix: .res 1
;---------------------------------------------------------------------
.data
open_param: .byte $03 ;PARAM_COUNT
.addr pathname ;PATHNAME
.byte $00 ;IO_BUFFER (Lo)
.byte >_uip_buf+1 ;IO_BUFFER (Hi)
open_fd: .byte $00 ;REF_NUM
read_param: .byte $04 ;PARAM_COUNT
read_fd: .byte $00 ;REF_NUM
read_buffer: .addr $0000 ;DATA_BUFFER
read_count_in: .word $0000 ;REQUEST_COUNT
read_count_out: .word $0000 ;TRANS_COUNT
close_param: .byte $01 ;PARAM_COUNT
close_fd: .byte $00 ;REF_NUM
;---------------------------------------------------------------------
.segment "INIT"
init_pfs:
; Get prefix len of path used to load binary
ldx pathname
: lda pathname,x
cmp #'/'
beq :+
dex
bne :-
: stx prefix
rts
;---------------------------------------------------------------------
.code
_pfs_open:
; Pop and store name
jsr popax
sta ptr1
stx ptr1+1
; Append name to prefix
ldy #$00
ldx prefix
: lda (ptr1),y
beq :+
sta pathname+1,x
iny
inx
bne :-
: stx pathname
jsr mli
.byte OPEN_CALL
.addr open_param
bcs error
; Return fd
lda open_fd
ldx #$00
rts
_pfs_read:
; Store len requested
sta read_count_in
stx read_count_in+1
; Pop and store buf
jsr popax
sta read_buffer
stx read_buffer+1
; Pop and store fd
jsr popax
sta read_fd
jsr mli
.byte READ_CALL
.addr read_param
bcs error
; Return len read
lda read_count_out
ldx read_count_out+1
rts
done_pfs:
lda #$00
_pfs_close:
; Store fd
sta close_fd
jsr mli
.byte CLOSE_CALL
.addr close_param
bcs error
rts
error:
; Return -1
lda #$FF
tax
rts
;---------------------------------------------------------------------