3562eb462488109817a8a75fba6b15dc8d4bc221
[openwrt/openwrt.git] / package / base-files / 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 #define FILENAME "/dev/mtdblock/1"
37
38 struct trx_header {
39 unsigned magic; /* "HDR0" */
40 unsigned len; /* Length of file including header */
41 unsigned crc32; /* 32-bit CRC from flag_version to end of file */
42 unsigned flag_version; /* 0:15 flags, 16:31 version */
43 unsigned offsets[3]; /* Offsets of partitions from start of header */
44 };
45
46 unsigned long *crc32;
47
48 void init_crc32()
49 {
50 unsigned long crc;
51 unsigned long poly = 0xEDB88320L;
52 int n, bit;
53 if ((crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long))) == (void *)-1) {
54 perror("malloc");
55 exit(1);
56 }
57 for (n = 0; n < 256; n++) {
58 crc = (unsigned long) n;
59 for (bit = 0; bit < 8; bit++)
60 crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
61 crc32[n] = crc;
62 }
63 }
64
65 unsigned int crc32buf(char *buf, size_t len)
66 {
67 unsigned int crc = 0xFFFFFFFF;
68 for (; len; len--, buf++)
69 crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
70 return crc;
71 }
72
73 int main(int argc, char **argv)
74 {
75 int fd;
76 struct mtd_info_user mtdInfo;
77 unsigned long len;
78 struct trx_header *ptr;
79 char *buf;
80
81 if (((fd = open(FILENAME, O_RDWR)) < 0)
82 || ((len = lseek(fd, 0, SEEK_END)) < 0)
83 || ((ptr = (struct trx_header *) mmap(0, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1))
84 || (ptr->magic != 0x30524448)) {
85 printf("Error reading trx info\n");
86 exit(-1);
87 }
88 close (fd);
89
90 if (((fd = open("/dev/mtd/1", O_RDWR)) < 0)
91 || (ioctl(fd, MEMGETINFO, &mtdInfo))) {
92 fprintf(stderr, "Could not get MTD device info from %s\n", FILENAME);
93 close(fd);
94 exit(1);
95 }
96 close(fd);
97
98 if (argc > 1 && !strcmp(argv[1],"--move")) {
99 if (ptr->offsets[2] >= ptr->len) {
100 printf("Partition already moved outside trx\n");
101 } else {
102 init_crc32();
103 ptr->offsets[2] += (mtdInfo.erasesize - 1);
104 ptr->offsets[2] &= ~(mtdInfo.erasesize - 1);
105 ptr->len = ptr->offsets[2];
106 ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));
107 msync(ptr,sizeof(struct trx_header),MS_SYNC|MS_INVALIDATE);
108 printf("Partition moved; please reboot\n");
109 }
110 } else if (argc > 1 && !strcmp(argv[1], "--clean")) {
111 buf = (char *) ptr;
112 if (buf[ptr->offsets[1] - 1] == 0) {
113 init_crc32();
114 buf[ptr->offsets[1] - 1] = 1;
115 ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));
116 msync(ptr,sizeof(struct trx_header),MS_SYNC|MS_INVALIDATE);
117 printf("Partition marked as clean\n");
118 }
119 } else {
120 int x;
121 printf(" erase: 0x%08x\n",mtdInfo.erasesize);
122 printf("=== trx ===\n");
123 printf("mapped: 0x%08x\n", (unsigned)ptr);
124 printf(" magic: 0x%08x\n", ptr->magic);
125 printf(" len: 0x%08x\n", ptr->len);
126 printf(" crc: 0x%08x\n", ptr->crc32);
127 for (x = 0; x < 3; x++)
128 printf(" offset[%d]: 0x%08x\n", x, ptr->offsets[x]);
129 }
130
131 munmap((void *) ptr, len);
132 return 0;
133 }