1/* 2 * imagetag.c 3 * 4 * Copyright (C) 2005 Mike Baker 5 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org> 6 * Copyrigth (C) 2010 Daniel Dickinson <openwrt@cshore.neomailbox.net> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 2 11 * of the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 21 */ 22 23#include <stdio.h> 24#include <stdlib.h> 25#include <stddef.h> 26#include <unistd.h> 27#include <fcntl.h> 28#include <sys/mman.h> 29#include <sys/stat.h> 30#include <string.h> 31#include <errno.h> 32 33#include <sys/ioctl.h> 34#include <mtd/mtd-user.h> 35#include "mtd.h" 36#include "crc32.h" 37#include "bcm_tag.h" 38 39ssize_t pread(int fd, void *buf, size_t count, off_t offset); 40ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset); 41 42#define CRC_START 0xFFFFFFFF 43 44static uint32_t strntoul(char *str, char **endptr, int base, size_t len) { 45 char *newstr; 46 uint32_t res = 0; 47 48 newstr = calloc(len + 1, sizeof(char)); 49 if (newstr) { 50 strncpy(newstr, str, len); 51 res = strtoul(newstr, endptr, base); 52 free(newstr); 53 } 54 return res; 55} 56 57uint32_t compute_crc32(uint32_t crc, off_t start, size_t compute_len, int fd) 58{ 59 uint8_t readbuf[1024]; 60 ssize_t res; 61 off_t offset = start; 62 63 /* Read a buffer's worth of bytes */ 64 while (fd && (compute_len >= sizeof(readbuf))) { 65 res = pread(fd, readbuf, sizeof(readbuf), offset); 66 crc = crc32(crc, readbuf, res); 67 compute_len = compute_len - res; 68 offset += res; 69 } 70 71 /* Less than buffer-size bytes remains, read compute_len bytes */ 72 if (fd && (compute_len > 0)) { 73 res = pread(fd, readbuf, compute_len, offset); 74 crc = crc32(crc, readbuf, res); 75 } 76 77 return crc; 78} 79 80int 81trx_fixup(int fd, const char *name) 82{ 83 struct mtd_info_user mtdInfo; 84 unsigned long len; 85 void *ptr, *scan; 86 int bfd; 87 struct bcm_tag *tag; 88 ssize_t res; 89 uint32_t cfelen, imagelen, imagestart, rootfslen; 90 uint32_t imagecrc, rootfscrc, headercrc; 91 uint32_t offset = 0; 92 cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0; 93 94 95 if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) { 96 fprintf(stderr, "Failed to get mtd info\n"); 97 goto err; 98 } 99 100 len = mtdInfo.size; 101 if (mtdInfo.size <= 0) { 102 fprintf(stderr, "Invalid MTD device size\n"); 103 goto err; 104 } 105 106 bfd = mtd_open(name, true); 107 ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0); 108 if (!ptr || (ptr == (void *) -1)) { 109 perror("mmap"); 110 goto err1; 111 } 112 113 tag = (struct bcm_tag *) (ptr); 114 115 cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN); 116 if (cfelen) { 117 fprintf(stderr, "Non-zero CFE length. This is currently unsupported.\n"); 118 exit(1); 119 } 120 121 headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd); 122 if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) { 123 fprintf(stderr, "Tag verify failed. This may not be a valid image.\n"); 124 exit(1); 125 } 126 127 sprintf(&tag->flashRootLength[0], "%lu", 0); 128 strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN); 129 130 imagestart = sizeof(tag); 131 memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN); 132 memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN); 133 rootfscrc = CRC_START; 134 memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t)); 135 headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC)); 136 memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t)); 137 138 msync(ptr, sizeof(struct bcm_tag), MS_SYNC|MS_INVALIDATE); 139 munmap(ptr, len); 140 close(bfd); 141 return 0; 142 143err1: 144 close(bfd); 145err: 146 fprintf(stderr, "Error fixing up imagetag header\n"); 147 return -1; 148} 149 150 151int 152trx_check(int imagefd, const char *mtd, char *buf, int *len) 153{ 154 struct bcm_tag *tag = (const struct bcm_tag *) buf; 155 int fd; 156 uint32_t headerCRC; 157 uint32_t imageLen; 158 159 if (strcmp(mtd, "linux") != 0) 160 return 1; 161 162 *len = read(imagefd, buf, sizeof(struct bcm_tag)); 163 if (*len < sizeof(struct bcm_tag)) { 164 fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len); 165 return 0; 166 } 167 headerCRC = crc32buf(buf, offsetof(struct bcm_tag, headerCRC)); 168 if (*(uint32_t *)(&tag->headerCRC[0]) != headerCRC) { 169 170 if (quiet < 2) { 171 fprintf(stderr, "Bad header CRC got %08lx, calculated %08lx\n", 172 *(uint32_t *)(&tag->headerCRC[0]), headerCRC); 173 fprintf(stderr, "This is not the correct file format; refusing to flash.\n" 174 "Please specify the correct file or use -f to force.\n"); 175 } 176 return 0; 177 } 178 179 /* check if image fits to mtd device */ 180 fd = mtd_check_open(mtd); 181 if(fd < 0) { 182 fprintf(stderr, "Could not open mtd device: %s\n", mtd); 183 exit(1); 184 } 185 186 imageLen = strntoul(&tag->totalLength[0], NULL, 10, IMAGE_LEN); 187 188 if(mtdsize < imageLen) { 189 fprintf(stderr, "Image too big for partition: %s\n", mtd); 190 close(fd); 191 return 0; 192 } 193 194 close(fd); 195 return 1; 196} 197 198int 199mtd_fixtrx(const char *mtd, size_t offset) 200{ 201 int fd; 202 struct bcm_tag *tag; 203 char *buf; 204 ssize_t res; 205 size_t block_offset; 206 uint32_t cfelen, imagelen, imagestart, rootfslen; 207 uint32_t imagecrc, rootfscrc, headercrc; 208 cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0; 209 210 if (quiet < 2) 211 fprintf(stderr, "Trying to fix trx header in %s at 0x%x...\n", mtd, offset); 212 213 block_offset = offset & ~(erasesize - 1); 214 offset -= block_offset; 215 216 fd = mtd_check_open(mtd); 217 if(fd < 0) { 218 fprintf(stderr, "Could not open mtd device: %s\n", mtd); 219 exit(1); 220 } 221 222 if (block_offset + erasesize > mtdsize) { 223 fprintf(stderr, "Offset too large, device size 0x%x\n", mtdsize); 224 exit(1); 225 } 226 227 buf = malloc(erasesize); 228 if (!buf) { 229 perror("malloc"); 230 exit(1); 231 } 232 233 res = pread(fd, buf, erasesize, block_offset); 234 if (res != erasesize) { 235 perror("pread"); 236 exit(1); 237 } 238 239 tag = (struct bcm_tag *) (buf + offset); 240 241 cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN); 242 if (cfelen) { 243 fprintf(stderr, "Non-zero CFE length. This is currently unsupported.\n"); 244 exit(1); 245 } 246 247 if (quiet < 2) { 248 fprintf(stderr, "Verifying we actually have an imagetag.\n"); 249 } 250 251 headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd); 252 if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) { 253 fprintf(stderr, "Tag verify failed. This may not be a valid image.\n"); 254 exit(1); 255 } 256 257 if (quiet < 2) { 258 fprintf(stderr, "Checking current fixed status.\n"); 259 } 260 261 rootfslen = strntoul(&tag->flashRootLength[0], NULL, 10, IMAGE_LEN); 262 if (rootfslen == 0) { 263 if (quiet < 2) 264 fprintf(stderr, "Header already fixed, exiting\n"); 265 close(fd); 266 return 0; 267 } 268 269 if (quiet < 2) { 270 fprintf(stderr, "Setting root length to 0.\n"); 271 } 272 273 sprintf(&tag->flashRootLength[0], "%lu", 0); 274 strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN); 275 276 if (quiet < 2) { 277 fprintf(stderr, "Recalculating CRCs.\n"); 278 } 279 280 imagestart = sizeof(tag); 281 memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN); 282 memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN); 283 rootfscrc = CRC_START; 284 memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t)); 285 headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC)); 286 memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t)); 287 288 if (quiet < 2) { 289 fprintf(stderr, "Erasing imagetag block\n"); 290 } 291 292 if (mtd_erase_block(fd, block_offset)) { 293 fprintf(stderr, "Can't erase block at 0x%x (%s)\n", block_offset, strerror(errno)); 294 exit(1); 295 } 296 297 if (quiet < 2) { 298 fprintf(stderr, "New image crc32: 0x%x, rewriting block\n", 299 *(uint32_t *)(&tag->imageCRC[0])); 300 fprintf(stderr, "New header crc32: 0x%x, rewriting block\n", headercrc); 301 } 302 303 if (pwrite(fd, buf, erasesize, block_offset) != erasesize) { 304 fprintf(stderr, "Error writing block (%s)\n", strerror(errno)); 305 exit(1); 306 } 307 308 if (quiet < 2) 309 fprintf(stderr, "Done.\n"); 310 311 close (fd); 312 sync(); 313 return 0; 314 315} 316