mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-09-06 19:54:33 +00:00
206 lines
6.3 KiB
C
206 lines
6.3 KiB
C
/**
|
|
* \addtogroup c64fs
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* "Raw" C64 file system access.
|
|
* \author Adam Dunkels <adam@dunkels.com>
|
|
*
|
|
* This file provides functions that allow reading data from files
|
|
* without updating the file descriptor pointer. The functions are not
|
|
* automatically included in the core Contiki code and therefore
|
|
* application programs that use tham must manually link with this
|
|
* file.
|
|
*
|
|
*/
|
|
|
|
|
|
/*
|
|
* Copyright (c) 2003, Adam Dunkels.
|
|
* 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. The name of the author may not be used to endorse or promote
|
|
* products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 desktop environment
|
|
*
|
|
* $Id: c64-fs-raw.c,v 1.1 2007/05/23 23:11:28 oliverschmidt Exp $
|
|
*
|
|
*/
|
|
|
|
#include "c64-fs-raw.h"
|
|
|
|
#include <string.h>
|
|
|
|
struct directory_entry {
|
|
unsigned char type;
|
|
unsigned char track, sect;
|
|
unsigned char name[16];
|
|
unsigned char reltrack, relsect, relreclen;
|
|
unsigned char unused1, unused2, unused3, unused4;
|
|
unsigned char tmptrack, tmpsect;
|
|
unsigned char blockslo, blockshi;
|
|
};
|
|
|
|
|
|
extern unsigned char _c64_fs_dirbuf[256];
|
|
extern unsigned char _c64_fs_dirbuftrack, _c64_fs_dirbufsect;
|
|
|
|
extern unsigned char _c64_fs_filebuf[256];
|
|
extern unsigned char _c64_fs_filebuftrack, _c64_fs_filebufsect;
|
|
|
|
void _c64_fs_readdirbuf(unsigned char track, unsigned char sect);
|
|
|
|
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/**
|
|
* Read data from a file without updating the file descriptor pointer.
|
|
*
|
|
* This function reads data from an open file into a buffer than must
|
|
* be allocated by the caller, but does not update the file
|
|
* description pointer like the c64_fs_read() function does.
|
|
*
|
|
* \param f A pointer to a file descriptor structure that must have
|
|
* been opened with c64_fs_open().
|
|
*
|
|
* \param buf A pointer to the buffer in which the data should be placed.
|
|
*
|
|
* \param len The maxiumum amount of bytes to read.
|
|
*
|
|
* \return The number of bytes that actually was read, or 0 if an end
|
|
* of file was encountered.
|
|
*
|
|
*/
|
|
/*-----------------------------------------------------------------------------------*/
|
|
int __fastcall__
|
|
c64_fs_read_raw(register struct c64_fs_file *f, char *buf, int len)
|
|
{
|
|
int i;
|
|
unsigned char fptr, ftrack, fsect;
|
|
|
|
/* Check if current block is already in buffer, and if not read it
|
|
from disk. */
|
|
if(_c64_fs_filebuftrack != f->track ||
|
|
_c64_fs_filebufsect != f->sect) {
|
|
_c64_fs_filebuftrack = f->track;
|
|
_c64_fs_filebufsect = f->sect;
|
|
c64_dio_read_block(_c64_fs_filebuftrack,
|
|
_c64_fs_filebufsect, _c64_fs_filebuf);
|
|
}
|
|
|
|
if(_c64_fs_filebuf[0] == 0 &&
|
|
f->ptr == _c64_fs_filebuf[1]) {
|
|
return 0; /* EOF */
|
|
}
|
|
|
|
fptr = f->ptr;
|
|
ftrack = f->track;
|
|
fsect = f->sect;
|
|
|
|
for(i = 0; i < len; ++i) {
|
|
*buf = _c64_fs_filebuf[fptr];
|
|
|
|
++fptr;
|
|
if(_c64_fs_filebuf[0] == 0) {
|
|
if(fptr == _c64_fs_filebuf[1]) {
|
|
/* End of file reached, we return the amount of bytes read so
|
|
far. */
|
|
return i + 1;
|
|
}
|
|
} else if(fptr == 0) {
|
|
|
|
/* Read new block into buffer and set buffer state
|
|
accordingly. */
|
|
_c64_fs_filebuftrack = ftrack = _c64_fs_filebuf[0];
|
|
_c64_fs_filebufsect = fsect = _c64_fs_filebuf[1];
|
|
fptr = 2;
|
|
c64_dio_read_block(_c64_fs_filebuftrack,
|
|
_c64_fs_filebufsect, _c64_fs_filebuf);
|
|
}
|
|
|
|
++buf;
|
|
}
|
|
return i;
|
|
}
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/**
|
|
* Move the file descriptior pointer forward in the file.
|
|
*
|
|
*
|
|
* \param f A pointer to a file descriptor structure that must have
|
|
* been opened with c64_fs_open().
|
|
*
|
|
* \param len The number of bytes the pointer should be moved forward.
|
|
*
|
|
* \return The number of bytes that the pointer actually was moved, or
|
|
* 0 if an end of file was encountered.
|
|
*/
|
|
/*-----------------------------------------------------------------------------------*/
|
|
int
|
|
c64_fs_read_next(register struct c64_fs_file *f, int len)
|
|
{
|
|
int i;
|
|
|
|
/* Check if current block is already in buffer, and if not read it
|
|
from disk. */
|
|
if(_c64_fs_filebuftrack != f->track ||
|
|
_c64_fs_filebufsect != f->sect) {
|
|
_c64_fs_filebuftrack = f->track;
|
|
_c64_fs_filebufsect = f->sect;
|
|
c64_dio_read_block(_c64_fs_filebuftrack,
|
|
_c64_fs_filebufsect, _c64_fs_filebuf);
|
|
}
|
|
|
|
if(_c64_fs_filebuf[0] == 0 &&
|
|
f->ptr == _c64_fs_filebuf[1]) {
|
|
return 0; /* EOF */
|
|
}
|
|
|
|
for(i = 0; i < len; ++i) {
|
|
|
|
++f->ptr;
|
|
if(_c64_fs_filebuf[0] == 0) {
|
|
if(f->ptr == _c64_fs_filebuf[1]) {
|
|
/* End of file reached, we return the amount of bytes read so
|
|
far. */
|
|
return i + 1;
|
|
}
|
|
} else if(f->ptr == 0) {
|
|
/* Read new block into buffer and set buffer state
|
|
accordingly. */
|
|
_c64_fs_filebuftrack = f->track = _c64_fs_filebuf[0];
|
|
_c64_fs_filebufsect = f->sect = _c64_fs_filebuf[1];
|
|
f->ptr = 2;
|
|
c64_dio_read_block(_c64_fs_filebuftrack,
|
|
_c64_fs_filebufsect, _c64_fs_filebuf);
|
|
}
|
|
}
|
|
return i;
|
|
}
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/** @} */
|