138 lines
3.4 KiB
C
138 lines
3.4 KiB
C
/*
|
|
* add_header.c - partially based on OpenWrt's motorola-bin.c
|
|
*
|
|
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
|
|
* Gabor Juhos <juhosg@openwrt.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License,
|
|
* version 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
/*
|
|
* The add_header utility used by various vendors preprends the buf
|
|
* image with a header containing a CRC32 value which is generated for the
|
|
* model id + reserved space for CRC32 + buf, then replaces the reserved
|
|
* area with the actual CRC32. This replacement tool mimics this behavior.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <stddef.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <sys/mman.h>
|
|
#include <string.h>
|
|
#include <netinet/in.h>
|
|
#include <inttypes.h>
|
|
|
|
#define BPB 8 /* bits/byte */
|
|
|
|
static uint32_t crc32[1<<BPB];
|
|
|
|
static void init_crc32()
|
|
{
|
|
const uint32_t poly = ntohl(0x2083b8ed);
|
|
int n;
|
|
|
|
for (n = 0; n < 1<<BPB; n++) {
|
|
uint32_t crc = n;
|
|
int bit;
|
|
|
|
for (bit = 0; bit < BPB; bit++)
|
|
crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
|
|
crc32[n] = crc;
|
|
}
|
|
}
|
|
|
|
static uint32_t crc32buf(unsigned char *buf, size_t len)
|
|
{
|
|
uint32_t crc = 0xFFFFFFFF;
|
|
|
|
for (; len; len--, buf++)
|
|
crc = crc32[(uint8_t)crc ^ *buf] ^ (crc >> BPB);
|
|
return ~crc;
|
|
}
|
|
|
|
struct header {
|
|
unsigned char model[16];
|
|
uint32_t crc;
|
|
};
|
|
|
|
static void usage(const char *) __attribute__ (( __noreturn__ ));
|
|
|
|
static void usage(const char *mess)
|
|
{
|
|
fprintf(stderr, "Error: %s\n", mess);
|
|
fprintf(stderr, "Usage: add_header model_id input_file output_file\n");
|
|
fprintf(stderr, "\n");
|
|
exit(1);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
off_t len; // of original buf
|
|
off_t buflen; // of the output file
|
|
int fd;
|
|
void *input_file; // pointer to the input file (mmmapped)
|
|
struct header header;
|
|
unsigned char *buf; // pointer to prefix + copy of original buf
|
|
|
|
// verify parameters
|
|
|
|
if (argc != 4)
|
|
usage("wrong number of arguments");
|
|
|
|
// mmap input_file
|
|
if ((fd = open(argv[2], O_RDONLY)) < 0
|
|
|| (len = lseek(fd, 0, SEEK_END)) < 0
|
|
|| (input_file = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)) == (void *) (-1)
|
|
|| close(fd) < 0)
|
|
{
|
|
fprintf(stderr, "Error loading file %s: %s\n", argv[2], strerror(errno));
|
|
exit(1);
|
|
}
|
|
|
|
buflen = len + sizeof(header);
|
|
|
|
init_crc32();
|
|
|
|
// copy model name into header
|
|
strncpy(header.model, argv[1], sizeof(header.model));
|
|
header.crc = 0;
|
|
|
|
// create a firmware image in memory and copy the input_file to it
|
|
buf = malloc(buflen);
|
|
memcpy(buf, &header, sizeof(header));
|
|
memcpy(&buf[sizeof(header)], input_file, len);
|
|
|
|
// CRC of temporary header + buf
|
|
header.crc = htonl(crc32buf(buf, buflen));
|
|
|
|
memcpy(buf, &header, sizeof(header));
|
|
|
|
// write the buf
|
|
if ((fd = open(argv[3], O_CREAT|O_WRONLY|O_TRUNC,0644)) < 0
|
|
|| write(fd, buf, buflen) != buflen
|
|
|| close(fd) < 0)
|
|
{
|
|
fprintf(stderr, "Error storing file %s: %s\n", argv[3], strerror(errno));
|
|
exit(2);
|
|
}
|
|
|
|
free(buf);
|
|
|
|
munmap(input_file,len);
|
|
|
|
return 0;
|
|
}
|