Mike Baker
19 years ago
parent
ab4f002e8d
commit
4d6bb280f0
@ -0,0 +1,108 @@
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/*
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* jffs2root.c
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*
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* Copyright (C) 2005 Mike Baker
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*
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* $Id$
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <string.h>
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#define FILENAME "/dev/mtdblock/1"
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struct trx_header {
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unsigned magic; /* "HDR0" */
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unsigned len; /* Length of file including header */
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unsigned crc32; /* 32-bit CRC from flag_version to end of file */
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unsigned flag_version; /* 0:15 flags, 16:31 version */
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unsigned offsets[3]; /* Offsets of partitions from start of header */
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};
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unsigned long *crc32;
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void init_crc32()
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{
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unsigned long crc;
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unsigned long poly = 0xEDB88320L;
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int n, bit;
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crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long));
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for (n = 0; n < 256; n++) {
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crc = (unsigned long) n;
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for (bit = 0; bit < 8; bit++)
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crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
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crc32[n] = crc;
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}
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}
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unsigned int crc32buf(char *buf, size_t len)
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{
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unsigned int crc = 0xFFFFFFFF;
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for (; len; len--, buf++)
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crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
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return crc;
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}
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int main(int argc, char **argv)
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{
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int fd;
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unsigned long len;
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struct trx_header *ptr;
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if (((fd = open(FILENAME, O_RDWR)) < 0)
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|| ((len = lseek(fd, 0, SEEK_END)) < 0)
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|| ((ptr = (struct trx_header *) mmap(0, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1))
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|| (ptr->magic != 0x30524448)) {
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printf("Error reading trx info\n");
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exit(-1);
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}
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if (argc > 1 && !strcmp(argv[1],"--move")) {
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if (ptr->offsets[1] >= ptr->len) {
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printf("Partition already moved outside trx\n");
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} else if (ptr->offsets[1] & 0x0001ffff) {
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printf("Partition does not start on a block boundary\n");
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} else {
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init_crc32();
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bzero((void *)((int)ptr + ptr->len), (size_t)(len - ptr->len));
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ptr->len = ptr->offsets[1];
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ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));
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msync(ptr,len,MS_SYNC|MS_INVALIDATE);
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printf("Partition moved; please reboot\n");
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}
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} else {
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int x;
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printf("=== trx ===\n");
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printf("mapped: 0x%08x\n", (unsigned)ptr);
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printf(" magic: 0x%08x\n", ptr->magic);
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printf(" len: 0x%08x\n", ptr->len);
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printf(" crc: 0x%08x\n", ptr->crc32);
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for (x = 0; x < 3; x++)
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printf(" offset[%d]: 0x%08x\n", x, ptr->offsets[x]);
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}
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munmap((void *) ptr, sizeof(struct trx_header));
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return 0;
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}
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