tools/firmware-utils/src/wrt400n.c

   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 <arpa/inet.h>
  11 #include <fcntl.h>
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <string.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <unistd.h>
  18
  19 #include "cyg_crc.h"
  20
  21 // https://dev.openwrt.org/browser/trunk/target/linux/rdc-2.6/files/drivers/mtd/maps/rdc3210.c
  22 static uint32_t crctab[257] =
  23 {
  24         0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
  25         0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
  26         0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
  27         0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
  28         0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
  29         0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  30         0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
  31         0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
  32         0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
  33         0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  34         0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
  35         0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
  36         0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
  37         0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
  38         0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  39         0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
  40         0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
  41         0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
  42         0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
  43         0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  44         0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
  45         0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
  46         0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
  47         0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
  48         0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
  49         0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
  50         0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
  51         0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
  52         0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
  53         0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  54         0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
  55         0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
  56         0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
  57         0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
  58         0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
  59         0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
  60         0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
  61         0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
  62         0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
  63         0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  64         0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
  65         0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
  66         0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
  67         0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
  68         0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  69         0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
  70         0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
  71         0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
  72         0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
  73         0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  74         0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
  75         0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
  76         0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
  77         0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
  78         0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
  79         0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
  80         0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
  81         0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
  82         0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
  83         0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  84         0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
  85         0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
  86         0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
  87         0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
  88         0
  89 };
  90
  91 static uint32_t crc32(uint8_t* buf, uint32_t len)
  92 {
  93         register int i;
  94         uint32_t sum;
  95         register uint32_t s0;
  96         s0 = ~0;
  97         for (i = 0; i < len; i++)
  98         {
  99                 s0 = (s0 >> 8) ^ crctab[(uint8_t) (s0 & 0xFF) ^ buf[i]];
 100         }
 101         sum = ~s0;
 102         return sum;
 103 }
 104
 105 #define HEADERSIZE      60
 106 #define MAGIC           "GMTKRT400N"
 107
 108 // global variables
 109 uint8_t kernelbuf[0x100000];    // kernel - lzma - uImage
 110 uint8_t rootfsbuf[0x2FFFC4];    // root - squashfs
 111
 112 uint8_t buf[0x400000];          // buffer for image
 113
 114
 115 // Header format:
 116 //
 117 //              GPL Tarball: http://downloads.linksysbycisco.com/downloads/WRT400N_1.0.01.19_US.tar,0.gz
 118 //              File: WRT400N_1.0.01.19_US/FW_WRT400N_1.0.01.19_US_20081229/GTK/user/include/fw_upgrade.h
 119 //
 120 //
 121 //              Struct:
 122 //                      typedef struct
 123 //                      {
 124 //                              UINT32          checksum;               /* CRC32 */
 125 //                              UINT8                   magic[11];              /* The value of GTIMG_MAGIC */
 126 //                              UINT32          kernel_length;          /* The length of the kernel image */
 127 //                              //UINT32                kernel_entry_point;     /* Kernel's entry point for RedBoot's information */
 128 //                              UINT32          kernel_upgrade_flag;    /* Set to 1 if we need to upgrade the kernel parition of the Flash */
 129 //                              UINT32          rootfs_length;          /* The length of the rootfs image */
 130 //                              //UINT32                rootfs_entry_point;     /* Not in use */
 131 //                              UINT32          rootfs_upgrade_flag;    /* Set to 1 if we need to upgrade the rootfs parition of the Flash */
 132 //
 133 //                              // Add 3 items by Vic Yu, 2006-05/10
 134 //                              UINT32          kernel_checksum;
 135 //                              UINT32          rootfs_checksum;
 136 //                              UINT32          fw_totalsize;
 137 //                              UINT32          reserved[4];
 138 //                      }imghdr_t , *pLinuxFWHeader_T;
 139 //
 140 //
 141 //              Description
 142 //                      - checksum:                     CRC32 of kernel and root fs, back to back
 143 //                      - magic:                                GMTKRT400N
 144 //                      - kernel_length:                kernel length in bytes
 145 //                      - kernel_upgrade_flag:  should we upgrade the kernel - set to 1
 146 //                      - rootfs_length:                root fs length in byte
 147 //                      - rootfs_upgrade_flag:  should we upgrade the root fs - set to 1
 148 //                      - kernel_checksum:              Gary S. Brown's 32 bit CRC algorithm for kernel, with remaining bits
 149 //                                                                      set to 0xFF upto 0x100000 bytes (total length)
 150 //                      - rootfs_checksum:              Gary S. Brown's 32 bit CRC algorithm for root fs, with remaining bits
 151 //                                                                      set to 0xFF upto 0x2FFFC4 bytes (total length)
 152 //                      - fw_totalsize:                 total firmware image file length (header length + kernel length + root fs length)
 153 //                      - reserved[4]:                  reserved ??? - set to all 0xFF
 154
 155
 156
 157 int main(int argc, char *argv[])
 158 {
 159         // file descriptors ...
 160         int             kernelfd                = -1;
 161         int             rootfsfd                        = -1;
 162         int                     outfd                   = -1;
 163
 164         char*           kernelfilename  = NULL;
 165         char*           rootfsfilename  = NULL;
 166         char*           outputfilename  = NULL;
 167
 168         // file sizes
 169         uint32_t        kernelsize              = 0;
 170         uint32_t        rootfssize              = 0;
 171         uint32_t        totalsize               = 0;
 172
 173         // header flags
 174         uint32_t        kernelflag              = 0;
 175         uint32_t        rootfsflag              = 0;
 176
 177         // checksums
 178         uint32_t        kernelchecksum  = 0;
 179         uint32_t        rootfschecksum  = 0;
 180         uint32_t        crc                             = 0;
 181
 182         if(argc != 4)
 183         {
 184                 printf("Usage:\n\t%s <kernel file> <rootfs file> <output file>\n", argv[0]);
 185                 return 1;
 186         }
 187
 188         kernelfilename = argv[1];
 189         rootfsfilename = argv[2];
 190         outputfilename = argv[3];
 191
 192         // Fill the kernel, rootfs, main buffer
 193         memset(kernelbuf, 0xFF, sizeof(kernelbuf));
 194         memset(rootfsbuf, 0xFF, sizeof(rootfsbuf));
 195         memset(buf, 0xFF, sizeof(buf));
 196
 197         // open the kernel ..
 198         kernelfd = open(kernelfilename, O_RDONLY);
 199
 200         if(kernelfd == -1)
 201         {
 202                 printf("Error: opening '%s'\n", kernelfilename);
 203                 goto done;
 204         }
 205
 206         // read in the kernel ...
 207         kernelsize = read(kernelfd, kernelbuf, sizeof(kernelbuf));
 208
 209         if(kernelsize == -1)
 210         {
 211                 printf("Error: reading '%s'\n", kernelfilename);
 212                 goto done;
 213         }
 214
 215         // calculate the kernel checksum ...
 216         kernelchecksum = cyg_crc32_accumulate(0, kernelbuf, sizeof(kernelbuf));
 217
 218         // print out stats
 219         printf("%s: size %d (0x%x), crc32 = 0x%x\n", kernelfilename, kernelsize, kernelsize, kernelchecksum);
 220
 221
 222         // open the root fs ..
 223         rootfsfd = open(rootfsfilename, O_RDONLY);
 224
 225         if(rootfsfd == -1)
 226         {
 227                 printf("Error: opening '%s'\n", rootfsfilename);
 228                 goto done;
 229         }
 230
 231         // read in the root fs ..
 232         rootfssize = read(rootfsfd, rootfsbuf, sizeof(rootfsbuf));
 233
 234         if(rootfssize == -1)
 235         {
 236                 printf("Error: reading '%s'\n", rootfsfilename);
 237                 goto done;
 238         }
 239
 240         // calculate the root fs checksum ...
 241         rootfschecksum = cyg_crc32_accumulate(0, rootfsbuf, sizeof(rootfsbuf));
 242
 243         // print out stats
 244         printf("%s: size %d (0x%x), crc32 = 0x%x\n", rootfsfilename, rootfssize, rootfssize, rootfschecksum);
 245
 246
 247         // now for the header ...
 248
 249         totalsize = HEADERSIZE;
 250
 251         // copy over kernel
 252         memcpy(buf + totalsize, kernelbuf, kernelsize);
 253         totalsize += kernelsize;
 254
 255         // copy over root fs
 256         memcpy(buf + totalsize, rootfsbuf, rootfssize);
 257         totalsize += rootfssize;
 258
 259         // calculate crc
 260         crc = crc32(buf + HEADERSIZE, totalsize - HEADERSIZE);
 261
 262         // print some stats out
 263         printf("crc = 0x%x, total size = %d (0x%x)\n", crc, totalsize, totalsize);
 264
 265         // copy crc into header
 266         crc = htonl(crc);
 267         memcpy(buf, &crc, sizeof(crc));
 268
 269         // copy over magic
 270         strcpy((char *)buf + 4, MAGIC);
 271
 272         // copy over kernel size
 273         kernelsize = htonl(kernelsize);
 274         memcpy(buf + 16, &kernelsize, sizeof(kernelsize));
 275
 276         // copy over kernal flag
 277         kernelflag = htonl(0x1);
 278         memcpy(buf + 20, &kernelflag, sizeof(kernelflag));
 279
 280         // copy over root fs size
 281         rootfssize = htonl(rootfssize);
 282         memcpy(buf + 24, &rootfssize, sizeof(rootfssize));
 283
 284         // copy over root fs flag
 285         rootfsflag = htonl(0x1);
 286         memcpy(buf + 28, &rootfsflag, sizeof(rootfsflag));
 287
 288         // copy over kernel check sum
 289         kernelchecksum = htonl(kernelchecksum);
 290         memcpy(buf + 32, &kernelchecksum, sizeof(kernelchecksum));
 291
 292         // copy over root fs checksum
 293         rootfschecksum = htonl(rootfschecksum);
 294         memcpy(buf + 36, &rootfschecksum, sizeof(rootfschecksum));
 295
 296         // copy over total size
 297         totalsize = htonl(totalsize);
 298         memcpy(buf + 40, &totalsize, sizeof(totalsize));
 299
 300         // undo the htonl (for write)
 301         totalsize = htonl(totalsize);
 302
 303
 304         // write out the file from the buffer
 305         outfd = open(outputfilename, O_CREAT | O_WRONLY | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 306
 307         if(outfd == -1)
 308         {
 309                 printf("ERROR: opening '%s' for write\n", outputfilename);
 310         }
 311
 312         write(outfd, buf, totalsize);
 313
 314 done:
 315         // close open fd's
 316
 317         if(kernelfd != -1)
 318         {
 319                 close(kernelfd);
 320                 kernelfd = -1;
 321         }
 322
 323         if(rootfsfd != -1)
 324         {
 325                 close(rootfsfd);
 326                 rootfsfd = -1;
 327         }
 328
 329         if(outfd != -1)
 330         {
 331                 close(outfd);
 332                 outfd = -1;
 333         }
 334
 335         return 0;
 336 }