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 20static 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 89static 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 107uint8_t kernelbuf[0x100000]; // kernel - lzma - uImage 108uint8_t rootfsbuf[0x2FFFC4]; // root - squashfs 109 110uint8_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 155int 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 312done: 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