source: freewrt/tools/brcm-utils/src/motorola-bin.c@ fdd4f59

/*
 * motorola-bin.c
 *
 * Copyright (C) 2005-2006 Mike Baker,
 *                         Imre Kaloz <kaloz@openwrt.org>
 *                         OpenWrt.org
 *
 * $Id: motorola-bin.c 3156 2006-02-06 00:07:27Z kaloz $
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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.
 *
 */

/*
 * February 1, 2006
 *
 * Add support for for creating WA840G and WE800G images
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <string.h>
#include <netinet/in.h>

unsigned long *crc32;

void init_crc32()
{
    unsigned long crc;
    unsigned long poly = ntohl(0x2083b8ed);
    int n, bit;
    if ((crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long))) == (void *)-1) {
       perror("malloc");
       exit(1);
    }
    for (n = 0; n < 256; n++) {
        crc = (unsigned long) n;
        for (bit = 0; bit < 8; bit++)
            crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
        crc32[n] = crc;
    }
}

unsigned int crc32buf(char *buf, size_t len)
{
    unsigned int crc = 0xFFFFFFFF;
    for (; len; len--, buf++)
        crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
    return crc;
}

struct motorola {
        unsigned int crc;       // crc32 of the remainder
        unsigned int flags;     // unknown, 105770*
        char *trx;              // standard trx
};

void usage(void) __attribute__ (( __noreturn__ ));

void usage(void)
{
        printf("Usage: motorola-bin [-device] [trxfile] [binfile]\n\n");
        printf("Known devices: 1 - WR850G | 2 - WA840G | 3 - WE800G\n");
        exit(1);
}

int main(int argc, char **argv)
{
        unsigned int len;
        int fd;
        int c;
        void *trx;
        struct motorola *firmware;

        // verify parameters

        if (argc!=4)
        {
        usage();
        }

        // mmap trx file
        if (((fd = open(argv[2], O_RDONLY))  < 0)
        || ((len = lseek(fd, 0, SEEK_END)) < 0)
        || ((trx = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)) == (void *) (-1))
        || (close(fd) < 0)) {
                perror("open/malloc");
                exit(1);
        }
        
        // create a firmware image in memory
        // and copy the trx to it
        firmware = malloc(len+8);
        memcpy(&firmware->trx,trx,len);
        munmap(trx,len);

        // setup the motorola headers
        init_crc32();

        // setup the firmware magic

        while ((c = getopt(argc, argv, "123")) !=-1) {
                switch (c) {
                        case '1':
                                firmware->flags = ntohl(0x10577050); // Motorola WR850G
                                break;
                        case '2':
                                firmware->flags = ntohl(0x10577040); // Motorola WA840G
                                break;
                        case '3':
                                firmware->flags = ntohl(0x10577000); // Motorola WE800G
                                break;
                        default:
                                usage();
                }
        }

        firmware->crc   = htonl(crc32buf((char *)&firmware->flags,len+4));

        // write the firmware
        if (((fd = open(argv[3], O_CREAT|O_WRONLY,0644)) < 0)
        || (write(fd,firmware,len+8) != len+8)
        || (close(fd) < 0)) {
                perror("write");
                exit(-1);
        }

        free(firmware);

        return 0;
}