summaryrefslogtreecommitdiff
path: root/package/mtd/src/imagetag.c
blob: f6095be44afa38f5346d3842f58c28bf93efdb44 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
/*
 * imagetag.c
 *
 * Copyright (C) 2005 Mike Baker
 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
 * Copyrigth (C) 2010 Daniel Dickinson <openwrt@cshore.neomailbox.net>
 *
 * 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.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <string.h>
#include <errno.h>

#include <sys/ioctl.h>
#include "mtd-api.h"
#include "mtd.h"
#include "crc32.h"
#include "bcm_tag.h"

ssize_t pread(int fd, void *buf, size_t count, off_t offset);
ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);

#define CRC_START 0xFFFFFFFF

static uint32_t strntoul(char *str, char **endptr, int base, size_t len) {
  char *newstr;
  uint32_t res = 0;

  newstr = calloc(len + 1, sizeof(char));
  if (newstr) {
	strncpy(newstr, str, len); 
	res = strtoul(newstr, endptr, base);
	free(newstr);
  }
  return res;
}

uint32_t compute_crc32(uint32_t crc, off_t start, size_t compute_len, int fd)
{
	uint8_t readbuf[1024];
	ssize_t res;
	off_t offset = start;

	/* Read a buffer's worth of bytes  */
	while (fd && (compute_len >= sizeof(readbuf))) {
		res = pread(fd, readbuf, sizeof(readbuf), offset);
		crc = crc32(crc, readbuf, res);
		compute_len = compute_len - res;
		offset += res;
	}

	/* Less than buffer-size bytes remains, read compute_len bytes */
	if (fd && (compute_len > 0)) {
	  res = pread(fd, readbuf, compute_len, offset);
	  crc = crc32(crc, readbuf, res);
	}

	return crc;
}

int
trx_fixup(int fd, const char *name)
{
	struct mtd_info_user mtdInfo;
	unsigned long len;
	void *ptr, *scan;
	int bfd;
	struct bcm_tag *tag;
	ssize_t res;
	uint32_t cfelen, imagelen, imagestart, rootfslen;
	uint32_t imagecrc, rootfscrc, headercrc;
	uint32_t offset = 0;
	cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;


	if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) {
		fprintf(stderr, "Failed to get mtd info\n");
		goto err;
	}

	len = mtdInfo.size;
	if (mtdInfo.size <= 0) {
		fprintf(stderr, "Invalid MTD device size\n");
		goto err;
	}

	bfd = mtd_open(name, true);
	ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0);
	if (!ptr || (ptr == (void *) -1)) {
		perror("mmap");
		goto err1;
	}

	tag = (struct bcm_tag *) (ptr);

	cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN);
	if (cfelen) {
	  fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
	  exit(1);
	}

	headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd);
	if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) {
		fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
		exit(1);
	}

	sprintf(&tag->flashRootLength[0], "%lu", 0);
	strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN);

	imagestart = sizeof(tag);
	memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN);
	memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN);
	rootfscrc = CRC_START;
	memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t));
	headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC));
	memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t));

	msync(ptr, sizeof(struct bcm_tag), MS_SYNC|MS_INVALIDATE);
	munmap(ptr, len);
	close(bfd);
	return 0;

err1:
	close(bfd);
err:
	fprintf(stderr, "Error fixing up imagetag header\n");
	return -1;
}


int
trx_check(int imagefd, const char *mtd, char *buf, int *len)
{
    struct bcm_tag *tag = (const struct bcm_tag *) buf;
	int fd;
	uint32_t headerCRC;
	uint32_t imageLen;

	if (strcmp(mtd, "linux") != 0)
		return 1;

	*len = read(imagefd, buf, sizeof(struct bcm_tag));
	if (*len < sizeof(struct bcm_tag)) {
		fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len);
		return 0;
	}
	headerCRC = crc32buf(buf, offsetof(struct bcm_tag, headerCRC));
	if (*(uint32_t *)(&tag->headerCRC[0]) != headerCRC) {
  
	  if (quiet < 2) {
		fprintf(stderr, "Bad header CRC got %08lx, calculated %08lx\n",
				*(uint32_t *)(&tag->headerCRC[0]), headerCRC);
		fprintf(stderr, "This is not the correct file format; refusing to flash.\n"
				"Please specify the correct file or use -f to force.\n");
	  }
	  return 0;
	}

	/* check if image fits to mtd device */
	fd = mtd_check_open(mtd);
	if(fd < 0) {
		fprintf(stderr, "Could not open mtd device: %s\n", mtd);
		exit(1);
	}

	imageLen = strntoul(&tag->totalLength[0], NULL, 10, IMAGE_LEN);
	
	if(mtdsize < imageLen) {
		fprintf(stderr, "Image too big for partition: %s\n", mtd);
		close(fd);
		return 0;
	}

	close(fd);
	return 1;
}

int
mtd_fixtrx(const char *mtd, size_t offset)
{
	int fd;
	struct bcm_tag *tag;
	char *buf;
	ssize_t res;
	size_t block_offset;
	uint32_t cfelen, imagelen, imagestart, rootfslen;
	uint32_t imagecrc, rootfscrc, headercrc;
	cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;

	if (quiet < 2)
		fprintf(stderr, "Trying to fix trx header in %s at 0x%x...\n", mtd, offset);

	block_offset = offset & ~(erasesize - 1);
	offset -= block_offset;

	fd = mtd_check_open(mtd);
	if(fd < 0) {
		fprintf(stderr, "Could not open mtd device: %s\n", mtd);
		exit(1);
	}

	if (block_offset + erasesize > mtdsize) {
		fprintf(stderr, "Offset too large, device size 0x%x\n", mtdsize);
		exit(1);
	}

	buf = malloc(erasesize);
	if (!buf) {
		perror("malloc");
		exit(1);
	}

	res = pread(fd, buf, erasesize, block_offset);
	if (res != erasesize) {
		perror("pread");
		exit(1);
	}

	tag = (struct bcm_tag *) (buf + offset);

	cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN);
	if (cfelen) {
	  fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
	  exit(1);
	}

	if (quiet < 2) {
	  fprintf(stderr, "Verifying we actually have an imagetag.\n");
	}

	headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd);
	if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) {
		fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
		exit(1);
	}

	if (quiet < 2) {
	  fprintf(stderr, "Checking current fixed status.\n");
	}

	rootfslen = strntoul(&tag->flashRootLength[0], NULL, 10, IMAGE_LEN);
	if (rootfslen == 0) {
	  if (quiet < 2) 
		fprintf(stderr, "Header already fixed, exiting\n");
	  close(fd);
	  return 0;
	}

	if (quiet < 2) {
	  fprintf(stderr, "Setting root length to 0.\n");
	}

	sprintf(&tag->flashRootLength[0], "%lu", 0);
	strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN);

	if (quiet < 2) {
	  fprintf(stderr, "Recalculating CRCs.\n");
	}

	imagestart = sizeof(tag);
	memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN);
	memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN);
	rootfscrc = CRC_START;
	memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t));
	headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC));
	memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t));

	if (quiet < 2) {
	  fprintf(stderr, "Erasing imagetag block\n");
	}

	if (mtd_erase_block(fd, block_offset)) {
		fprintf(stderr, "Can't erase block at 0x%x (%s)\n", block_offset, strerror(errno));
		exit(1);
	}

	if (quiet < 2) {
	  fprintf(stderr, "New image crc32: 0x%x, rewriting block\n", 
			  *(uint32_t *)(&tag->imageCRC[0]));
	  fprintf(stderr, "New header crc32: 0x%x, rewriting block\n", headercrc);  
	}

	if (pwrite(fd, buf, erasesize, block_offset) != erasesize) {
		fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
		exit(1);
	}

	if (quiet < 2)
		fprintf(stderr, "Done.\n");

	close (fd);
	sync();
	return 0;

}