target/linux/brcm-2.4/src/jffs2root.c

   1 /*
   2  * jffs2root.c
   3  *
   4  * Copyright (C) 2005 Mike Baker
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  19  *
  20  * $Id$
  21  *
  22  */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <stddef.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29 #include <sys/mman.h>
  30 #include <sys/stat.h>
  31 #include <string.h>
  32
  33 #include <sys/ioctl.h>
  34 #include "mtd.h"
  35
  36 struct trx_header {
  37         unsigned magic;         /* "HDR0" */
  38         unsigned len;           /* Length of file including header */
  39         unsigned crc32;         /* 32-bit CRC from flag_version to end of file */
  40         unsigned flag_version;  /* 0:15 flags, 16:31 version */
  41         unsigned offsets[3];    /* Offsets of partitions from start of header */
  42 };
  43
  44 unsigned long *crc32;
  45
  46 void init_crc32()
  47 {
  48         unsigned long crc;
  49         unsigned long poly = 0xEDB88320L;
  50         int n, bit;
  51         if ((crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long))) == (void *)-1) {
  52                 perror("malloc");
  53                 exit(1);
  54         }
  55         for (n = 0; n < 256; n++) {
  56         crc = (unsigned long) n;
  57         for (bit = 0; bit < 8; bit++)
  58                 crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
  59         crc32[n] = crc;
  60         }
  61 }
  62
  63 unsigned int crc32buf(char *buf, size_t len)
  64 {
  65         unsigned int crc = 0xFFFFFFFF;
  66         for (; len; len--, buf++)
  67         crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
  68         return crc;
  69 }
  70
  71 int main(int argc, char **argv)
  72 {
  73         int fd;
  74         struct mtd_info_user mtdInfo;
  75         unsigned long len;
  76         struct trx_header *ptr;
  77         char *buf;
  78
  79         if ((fd = open("/dev/mtdblock/1", O_RDWR)) < 0) {
  80                 fd = open("/dev/mtdblock1", O_RDWR);
  81         }
  82
  83         if (((len = lseek(fd, 0, SEEK_END)) < 0)
  84                         || ((ptr = (struct trx_header *) mmap(0, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1))
  85                         || (ptr->magic != 0x30524448)) {
  86                 printf("Error reading trx info\n");
  87                 exit(-1);
  88         }
  89
  90         close(fd);
  91
  92         if ((fd = open("/dev/mtd/1", O_RDWR)) < 0) {
  93                 fd = open("/dev/mtd1", O_RDWR);
  94         }
  95
  96         if (ioctl(fd, MEMGETINFO, &mtdInfo)) {
  97                 fprintf(stderr, "Could not get MTD device info from mtd\n");
  98                 close(fd);
  99                 exit(1);
 100         }
 101         close(fd);
 102
 103         if (argc > 1 && !strcmp(argv[1],"--move")) {
 104                 if (ptr->offsets[2] >= ptr->len) {
 105                         printf("Partition already moved outside trx\n");
 106                 } else {
 107                         init_crc32();
 108                         ptr->offsets[2] +=      (mtdInfo.erasesize - 1);
 109                         ptr->offsets[2] &= ~(mtdInfo.erasesize - 1);
 110                         ptr->len = ptr->offsets[2];
 111                         ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));
 112                         msync(ptr,sizeof(struct trx_header),MS_SYNC|MS_INVALIDATE);
 113                         printf("Partition moved; please reboot\n");
 114                 }
 115         } else if (argc > 1 && !strcmp(argv[1], "--clean")) {
 116                 buf = (char *) ptr;
 117                 if (buf[ptr->offsets[1] - 1] == 0) {
 118                         init_crc32();
 119                         buf[ptr->offsets[1] - 1] = 1;
 120                         ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));
 121                         msync(ptr,sizeof(struct trx_header),MS_SYNC|MS_INVALIDATE);
 122                         printf("Partition marked as clean\n");
 123                 }
 124         } else {
 125                 int x;
 126                 printf(" erase: 0x%08x\n",mtdInfo.erasesize);
 127                 printf("=== trx ===\n");
 128                 printf("mapped: 0x%08x\n", (unsigned)ptr);
 129                 printf(" magic: 0x%08x\n", ptr->magic);
 130                 printf("         len: 0x%08x\n", ptr->len);
 131                 printf("         crc: 0x%08x\n", ptr->crc32);
 132                 for (x = 0; x < 3; x++)
 133                         printf(" offset[%d]: 0x%08x\n", x, ptr->offsets[x]);
 134         }
 135
 136         munmap((void *) ptr, len);
 137         return 0;
 138 }