nes-proj/cpu/z80/loader/mef.c

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/*
* Copyright (c) 2007, Takahide Matsutsuka.
* 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.
*
* $Id: mef.c,v 1.1 2007/11/28 06:13:24 matsutsuka Exp $
*
*/
/*
* \file
* mef.c
* The Micro Executable Format
* \author
* Takahide Matsutsuka <markn@markn.org>
*/
#ifdef WITH_LOADER_ARCH
#include "contiki.h"
#include "loader/mef.h"
struct Area areas[MEF_AREA_MAX];
void
mef_load(unsigned char* offset)
{
unsigned char* start = offset;
unsigned char areasize = load_byte();
uint16_t relocsize;
unsigned int i, j;
uint16_t checksum = 0;
unsigned char* buf;
struct Relocation reloc;
for (i = 0; i < areasize; i++) {
buf = (unsigned char *) &areas[i];
for (j = 0; j < sizeof(struct Area); j++) {
*buf++ = load_byte();
}
}
for (i = 0; i < areasize; i++) {
for (j = 0; j < areas[i].size; j++) {
*offset = load_byte();
checksum += *offset;
offset++;
}
if (areas[i].checksum != checksum) {
// Checksum error!
}
}
// relocation information
relocsize = load_byte();
relocsize = (load_byte() << 8) + relocsize;
for (i = 0; i < relocsize; i++) {
buf = (unsigned char *) &reloc;
for (j = 0; j < sizeof(struct Relocation); j++) {
*buf++ = load_byte();
}
mef_reloc(start, &reloc);
}
}
void
mef_reloc(unsigned char* offset, struct Relocation *reloc)
{
if (reloc->mode & MEF_RELOC_ABSOLUTE) {
return;
}
offset += reloc->address;
if (reloc->mode & MEF_RELOC_MSB_BYTE) {
*offset = (unsigned char) ((reloc->data + (uint16_t) offset) >> 8);
} else if (reloc->mode & MEF_RELOC_LSB_BYTE) {
*offset = (unsigned char) ((reloc->data + (uint16_t) offset) & 0xff);
} else { /* word */
*offset++ = (unsigned char) ((reloc->data + (uint16_t) offset) & 0xff);
*offset = (unsigned char) ((reloc->data + (uint16_t) offset) >> 8);
}
}
#endif /* WITH_LOADER_ARCH */