| 1 | /* |
| 2 | * WRT400n - Firmware Generation Creator |
| 3 | * |
| 4 | * Creates a firmware image for the Linksys WRT400n router, |
| 5 | * that can be uploaded via the firmware upload page, |
| 6 | * from a kernel image file and root fs file |
| 7 | * |
| 8 | * Author: Sandeep Mistry |
| 9 | */ |
| 10 | #include <fcntl.h> |
| 11 | #include <stdio.h> |
| 12 | #include <stdint.h> |
| 13 | #include <string.h> |
| 14 | #include <sys/types.h> |
| 15 | #include <sys/stat.h> |
| 16 | |
| 17 | #include "cyg_crc.h" |
| 18 | |
| 19 | // https://dev.openwrt.org/browser/trunk/target/linux/rdc-2.6/files/drivers/mtd/maps/rdc3210.c |
| 20 | static uint32_t crctab[257] = |
| 21 | { |
| 22 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, |
| 23 | 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, |
| 24 | 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, |
| 25 | 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, |
| 26 | 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, |
| 27 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, |
| 28 | 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, |
| 29 | 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, |
| 30 | 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, |
| 31 | 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, |
| 32 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, |
| 33 | 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, |
| 34 | 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, |
| 35 | 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, |
| 36 | 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, |
| 37 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, |
| 38 | 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, |
| 39 | 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, |
| 40 | 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, |
| 41 | 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, |
| 42 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, |
| 43 | 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, |
| 44 | 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, |
| 45 | 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, |
| 46 | 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, |
| 47 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, |
| 48 | 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, |
| 49 | 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, |
| 50 | 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, |
| 51 | 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, |
| 52 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, |
| 53 | 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, |
| 54 | 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, |
| 55 | 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, |
| 56 | 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, |
| 57 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, |
| 58 | 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, |
| 59 | 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, |
| 60 | 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, |
| 61 | 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, |
| 62 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, |
| 63 | 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, |
| 64 | 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, |
| 65 | 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, |
| 66 | 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, |
| 67 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, |
| 68 | 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, |
| 69 | 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, |
| 70 | 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, |
| 71 | 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, |
| 72 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, |
| 73 | 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, |
| 74 | 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, |
| 75 | 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, |
| 76 | 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, |
| 77 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, |
| 78 | 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, |
| 79 | 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, |
| 80 | 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, |
| 81 | 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, |
| 82 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, |
| 83 | 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, |
| 84 | 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, |
| 85 | 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, |
| 86 | 0 |
| 87 | }; |
| 88 | |
| 89 | static uint32_t crc32(uint8_t* buf, uint32_t len) |
| 90 | { |
| 91 | register int i; |
| 92 | uint32_t sum; |
| 93 | register uint32_t s0; |
| 94 | s0 = ~0; |
| 95 | for (i = 0; i < len; i++) |
| 96 | { |
| 97 | s0 = (s0 >> 8) ^ crctab[(uint8_t) (s0 & 0xFF) ^ buf[i]]; |
| 98 | } |
| 99 | sum = ~s0; |
| 100 | return sum; |
| 101 | } |
| 102 | |
| 103 | #define HEADERSIZE 60 |
| 104 | #define MAGIC "GMTKRT400N" |
| 105 | |
| 106 | // global variables |
| 107 | uint8_t kernelbuf[0x100000]; // kernel - lzma - uImage |
| 108 | uint8_t rootfsbuf[0x2FFFC4]; // root - squashfs |
| 109 | |
| 110 | uint8_t buf[0x400000]; // buffer for image |
| 111 | |
| 112 | |
| 113 | // Header format: |
| 114 | // |
| 115 | // GPL Tarball: http://downloads.linksysbycisco.com/downloads/WRT400N_1.0.01.19_US.tar,0.gz |
| 116 | // File: WRT400N_1.0.01.19_US/FW_WRT400N_1.0.01.19_US_20081229/GTK/user/include/fw_upgrade.h |
| 117 | // |
| 118 | // |
| 119 | // Struct: |
| 120 | // typedef struct |
| 121 | // { |
| 122 | // UINT32 checksum; /* CRC32 */ |
| 123 | // UINT8 magic[11]; /* The value of GTIMG_MAGIC */ |
| 124 | // UINT32 kernel_length; /* The length of the kernel image */ |
| 125 | // //UINT32 kernel_entry_point; /* Kernel's entry point for RedBoot's information */ |
| 126 | // UINT32 kernel_upgrade_flag; /* Set to 1 if we need to upgrade the kernel parition of the Flash */ |
| 127 | // UINT32 rootfs_length; /* The length of the rootfs image */ |
| 128 | // //UINT32 rootfs_entry_point; /* Not in use */ |
| 129 | // UINT32 rootfs_upgrade_flag; /* Set to 1 if we need to upgrade the rootfs parition of the Flash */ |
| 130 | // |
| 131 | // // Add 3 items by Vic Yu, 2006-05/10 |
| 132 | // UINT32 kernel_checksum; |
| 133 | // UINT32 rootfs_checksum; |
| 134 | // UINT32 fw_totalsize; |
| 135 | // UINT32 reserved[4]; |
| 136 | // }imghdr_t , *pLinuxFWHeader_T; |
| 137 | // |
| 138 | // |
| 139 | // Description |
| 140 | // - checksum: CRC32 of kernel and root fs, back to back |
| 141 | // - magic: GMTKRT400N |
| 142 | // - kernel_length: kernel length in bytes |
| 143 | // - kernel_upgrade_flag: should we upgrade the kernel - set to 1 |
| 144 | // - rootfs_length: root fs length in byte |
| 145 | // - rootfs_upgrade_flag: should we upgrade the root fs - set to 1 |
| 146 | // - kernel_checksum: Gary S. Brown's 32 bit CRC algorithm for kernel, with remaining bits |
| 147 | // set to 0xFF upto 0x100000 bytes (total length) |
| 148 | // - rootfs_checksum: Gary S. Brown's 32 bit CRC algorithm for root fs, with remaining bits |
| 149 | // set to 0xFF upto 0x2FFFC4 bytes (total length) |
| 150 | // - fw_totalsize: total firmware image file length (header length + kernel length + root fs length) |
| 151 | // - reserved[4]: reserved ??? - set to all 0xFF |
| 152 | |
| 153 | |
| 154 | |
| 155 | int main(int argc, char *argv[]) |
| 156 | { |
| 157 | // file descriptors ... |
| 158 | int kernelfd = -1; |
| 159 | int rootfsfd = -1; |
| 160 | int outfd = -1; |
| 161 | |
| 162 | char* kernelfilename = NULL; |
| 163 | char* rootfsfilename = NULL; |
| 164 | char* outputfilename = NULL; |
| 165 | |
| 166 | // file sizes |
| 167 | uint32_t kernelsize = 0; |
| 168 | uint32_t rootfssize = 0; |
| 169 | uint32_t totalsize = 0; |
| 170 | |
| 171 | // header flags |
| 172 | uint32_t kernelflag = 0; |
| 173 | uint32_t rootfsflag = 0; |
| 174 | |
| 175 | // checksums |
| 176 | uint32_t kernelchecksum = 0; |
| 177 | uint32_t rootfschecksum = 0; |
| 178 | uint32_t crc = 0; |
| 179 | |
| 180 | if(argc != 4) |
| 181 | { |
| 182 | printf("Usage:\n\t%s <kernel file> <rootfs file> <output file>\n", argv[0]); |
| 183 | return 1; |
| 184 | } |
| 185 | |
| 186 | kernelfilename = argv[1]; |
| 187 | rootfsfilename = argv[2]; |
| 188 | outputfilename = argv[3]; |
| 189 | |
| 190 | // Fill the kernel, rootfs, main buffer |
| 191 | memset(kernelbuf, 0xFF, sizeof(kernelbuf)); |
| 192 | memset(rootfsbuf, 0xFF, sizeof(rootfsbuf)); |
| 193 | memset(buf, 0xFF, sizeof(buf)); |
| 194 | |
| 195 | // open the kernel .. |
| 196 | kernelfd = open(kernelfilename, O_RDONLY); |
| 197 | |
| 198 | if(kernelfd == -1) |
| 199 | { |
| 200 | printf("Error: opening '%s'\n", kernelfilename); |
| 201 | goto done; |
| 202 | } |
| 203 | |
| 204 | // read in the kernel ... |
| 205 | kernelsize = read(kernelfd, kernelbuf, sizeof(kernelbuf)); |
| 206 | |
| 207 | if(kernelsize == -1) |
| 208 | { |
| 209 | printf("Error: reading '%s'\n", kernelfilename); |
| 210 | goto done; |
| 211 | } |
| 212 | |
| 213 | // calculate the kernel checksum ... |
| 214 | kernelchecksum = cyg_crc32_accumulate(0, kernelbuf, sizeof(kernelbuf)); |
| 215 | |
| 216 | // print out stats |
| 217 | printf("%s: size %d (0x%x), crc32 = 0x%x\n", kernelfilename, kernelsize, kernelsize, kernelchecksum); |
| 218 | |
| 219 | |
| 220 | // open the root fs .. |
| 221 | rootfsfd = open(rootfsfilename, O_RDONLY); |
| 222 | |
| 223 | if(rootfsfd == -1) |
| 224 | { |
| 225 | printf("Error: opening '%s'\n", rootfsfilename); |
| 226 | goto done; |
| 227 | } |
| 228 | |
| 229 | // read in the root fs .. |
| 230 | rootfssize = read(rootfsfd, rootfsbuf, sizeof(rootfsbuf)); |
| 231 | |
| 232 | if(rootfssize == -1) |
| 233 | { |
| 234 | printf("Error: reading '%s'\n", rootfsfilename); |
| 235 | goto done; |
| 236 | } |
| 237 | |
| 238 | // calculate the root fs checksum ... |
| 239 | rootfschecksum = cyg_crc32_accumulate(0, rootfsbuf, sizeof(rootfsbuf)); |
| 240 | |
| 241 | // print out stats |
| 242 | printf("%s: size %d (0x%x), crc32 = 0x%x\n", rootfsfilename, rootfssize, rootfssize, rootfschecksum); |
| 243 | |
| 244 | |
| 245 | // now for the header ... |
| 246 | |
| 247 | totalsize = HEADERSIZE; |
| 248 | |
| 249 | // copy over kernel |
| 250 | memcpy(buf + totalsize, kernelbuf, kernelsize); |
| 251 | totalsize += kernelsize; |
| 252 | |
| 253 | // copy over root fs |
| 254 | memcpy(buf + totalsize, rootfsbuf, rootfssize); |
| 255 | totalsize += rootfssize; |
| 256 | |
| 257 | // calculate crc |
| 258 | crc = crc32(buf + HEADERSIZE, totalsize - HEADERSIZE); |
| 259 | |
| 260 | // print some stats out |
| 261 | printf("crc = 0x%x, total size = %d (0x%x)\n", crc, totalsize, totalsize); |
| 262 | |
| 263 | // copy crc into header |
| 264 | crc = htonl(crc); |
| 265 | memcpy(buf, &crc, sizeof(crc)); |
| 266 | |
| 267 | // copy over magic |
| 268 | strcpy((char *)buf + 4, MAGIC); |
| 269 | |
| 270 | // copy over kernel size |
| 271 | kernelsize = htonl(kernelsize); |
| 272 | memcpy(buf + 16, &kernelsize, sizeof(kernelsize)); |
| 273 | |
| 274 | // copy over kernal flag |
| 275 | kernelflag = htonl(0x1); |
| 276 | memcpy(buf + 20, &kernelflag, sizeof(kernelflag)); |
| 277 | |
| 278 | // copy over root fs size |
| 279 | rootfssize = htonl(rootfssize); |
| 280 | memcpy(buf + 24, &rootfssize, sizeof(rootfssize)); |
| 281 | |
| 282 | // copy over root fs flag |
| 283 | rootfsflag = htonl(0x1); |
| 284 | memcpy(buf + 28, &rootfsflag, sizeof(rootfsflag)); |
| 285 | |
| 286 | // copy over kernel check sum |
| 287 | kernelchecksum = htonl(kernelchecksum); |
| 288 | memcpy(buf + 32, &kernelchecksum, sizeof(kernelchecksum)); |
| 289 | |
| 290 | // copy over root fs checksum |
| 291 | rootfschecksum = htonl(rootfschecksum); |
| 292 | memcpy(buf + 36, &rootfschecksum, sizeof(rootfschecksum)); |
| 293 | |
| 294 | // copy over total size |
| 295 | totalsize = htonl(totalsize); |
| 296 | memcpy(buf + 40, &totalsize, sizeof(totalsize)); |
| 297 | |
| 298 | // undo the htonl (for write) |
| 299 | totalsize = htonl(totalsize); |
| 300 | |
| 301 | |
| 302 | // write out the file from the buffer |
| 303 | outfd = open(outputfilename, O_CREAT | O_WRONLY | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); |
| 304 | |
| 305 | if(outfd == -1) |
| 306 | { |
| 307 | printf("ERROR: opening '%s' for write\n", outputfilename); |
| 308 | } |
| 309 | |
| 310 | write(outfd, buf, totalsize); |
| 311 | |
| 312 | done: |
| 313 | // close open fd's |
| 314 | |
| 315 | if(kernelfd != -1) |
| 316 | { |
| 317 | close(kernelfd); |
| 318 | kernelfd = -1; |
| 319 | } |
| 320 | |
| 321 | if(rootfsfd != -1) |
| 322 | { |
| 323 | close(rootfsfd); |
| 324 | rootfsfd = -1; |
| 325 | } |
| 326 | |
| 327 | if(outfd != -1) |
| 328 | { |
| 329 | close(outfd); |
| 330 | outfd = -1; |
| 331 | } |
| 332 | |
| 333 | return 0; |
| 334 | } |
| 335 | |
