--- /dev/null
+/*
+ * Thanks to Vassily Galinsky for this tool
+*****************************************************************************
+AIRLINK AR525W firmware image structure
+ -8:-5 Extended (httpd) header checksum - sum2
+ -4:-1 Extended (httpd) header magic - "ARRN" - 0x4e525241
+ 0: 3 Standard (tftpd) header magic - "GMTK" - 0x4b544d47
+ 4: 7 Standard (tftpd) header checksum - sum1
+ 8: b 0
+ c: f Size of compressed linux kernel
+ 10:13 Size of firmware image file with standard header
+ 14:17 Product code - 0x5
+ 18:1b Bootloader checksum - sum0
+ 1c:1f 0
+ 20: Compressed linux kernel
+ - Squashfs or jffs2 file system - kernel dependent - either 32 bytes or sector aligned
+*****************************************************************************/
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+typedef unsigned long u32;
+typedef unsigned char uchar;
+
+u32 crctab[257] = {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+ 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+ 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+ 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+ 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+ 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+ 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+ 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+ 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+ 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+ 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+ 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+ 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+ 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+ 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+ 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+ 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+ 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+ 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+ 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+ 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+ 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+ 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+ 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+ 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+ 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+ 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+ 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+ 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+ 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+ 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+ 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+ 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+ 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+ 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+ 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+ 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+ 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+ 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+ 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+ 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+ 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+ 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+ 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+ 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+ 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+ 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+ 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+ 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+ 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+ 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+ 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+ 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+ 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+ 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+ 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+ 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+ 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+ 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+ 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
+ 0
+};
+
+u32 header[] = {
+ 0x00000000, 0x4e525241,
+ 0x4b544d47, 0x00000000, 0x00000000, 0x000afd4a,
+ 0x00000000, 0x00000005, 0x00000000, 0x00000000
+};
+
+static int JFFS2 = 0;
+
+int generate_image(char *kname, char *fsname, char *fname, int EHDR)
+{
+ int i;
+ u32 lenk, lens;
+ uchar *bk, *bs;
+ int fkd, ffd, fsd;
+ int pad = 0x1f;
+ fkd = open(kname, O_RDONLY);
+ ffd = creat(fname, 0x644);
+ if ((fkd < 0) || (ffd < 0))
+ return -1;
+ if (fsname) {
+ fsd = open(fsname, O_RDONLY);
+ if (fsd < 0)
+ return -1;
+ }
+ lenk = lseek(fkd, 0, SEEK_END);
+ header[5] = lenk;
+ bk = (uchar *) mmap(NULL, lenk, PROT_READ, MAP_SHARED, fkd, 0);
+ if (bk == MAP_FAILED)
+ return -1;
+ if (fsname) {
+ lens = lseek(fsd, 0, SEEK_END);
+ bs = (uchar *) mmap(NULL, lens, PROT_READ, MAP_SHARED, fsd,
+ 0);
+ if (bs == MAP_FAILED)
+ return -1;
+ }
+ if (EHDR)
+ write(ffd, header, 0x28);
+ else
+ write(ffd, header + 2, 0x20);
+ write(ffd, bk, lenk);
+ if (fsname && JFFS2)
+ pad = 0xffff;
+ printf("Padding header+kernel - 0x%x + 0x%x = 0x%x\n",
+ lenk + 0x20, ((lenk + 0x20) | pad) + 1 - lenk - 0x20,
+ ((lenk + 0x20) | pad) + 1);
+ for (i = 0; i < ((lenk + 0x20) | pad) + 1 - lenk - 0x20; i++)
+ write(ffd, header, 1);
+ if (fsname) {
+ write(ffd, bs, lens);
+ close(fsd);
+ }
+ close(ffd);
+ close(fkd);
+ return 0;
+}
+
+u32 crc32(uchar * buf, u32 len)
+{
+ register int i;
+ u32 sum;
+ register u32 s0;
+ s0 = ~0;
+ for (i = 0; i < len; i++) {
+ s0 = (s0 >> 8) ^ crctab[(uchar) (s0 & 0xFF) ^ buf[i]];
+ }
+ sum = ~s0;
+ return sum;
+}
+
+void usage(char *prog)
+{
+ printf("Usage: %s [-b 0/1] image_filename \n", prog);
+ printf(" update checksums for firmware file\n");
+ printf
+ ("Usage: %s [-b 0/1] [-j] [-e] kernel filesystem image_filename \n",
+ prog);
+ printf(" generate firmware file and update checksums\n");
+ printf("--------------------------------------------------\n");
+ printf(" -e - generate header for web upload\n");
+ printf(" -j - generate header for jffs2 filesystem\n");
+ printf(" -b 0/1 - clear/update bootloader checksum\n");
+}
+
+int main(int argc, char **argv)
+{
+ uchar b[0x400];
+ char EHDR = 0;
+ char BHDR = 0;
+ int c, fd;
+ extern char *optarg;
+ extern int optind, optopt;
+
+ while ((c = getopt(argc, argv, "b:e:j")) != -1) {
+ switch (c) {
+ case 'b':
+ if (optarg[0] == '1')
+ BHDR = 1;
+ break;
+ case 'e':
+ EHDR = 1;
+ break;
+ case 'j':
+ JFFS2 = 1;
+ break;
+ case '?':
+ fprintf(stderr, "\nError: unknown arg %c\n\n\n",
+ optopt);
+ usage(argv[0]);
+ exit(-1);
+ }
+ }
+ if (((argc - optind) < 1) && ((argc - optind) > 3)) {
+ usage(argv[0]);
+ exit(-1);
+ }
+ if ((argc - optind) == 3)
+ if (generate_image
+ (argv[optind], argv[optind + 1], argv[optind + 2],
+ EHDR)) {
+ fprintf(stderr,
+ "\nError generating image file %s\n\n\n",
+ argv[argc - 1]);
+ usage(argv[0]);
+ exit(-1);
+ }
+ if ((argc - optind) == 2)
+ if (generate_image
+ (argv[optind], NULL, argv[optind + 1], EHDR)) {
+ fprintf(stderr,
+ "\nError generating image file %s\n\n\n",
+ argv[argc - 1]);
+ usage(argv[0]);
+ exit(-1);
+ }
+
+ fd = open(argv[argc - 1], O_RDWR);
+ if (fd < 0) {
+ fprintf(stderr, "\nImage file not found %s\n\n\n",
+ argv[argc - 1]);
+ usage(argv[0]);
+ exit(-1);
+ }
+ long i, len = lseek(fd, 0, SEEK_END);
+ lseek(fd, 0, SEEK_SET);
+ uchar *buf = malloc(len);
+ read(fd, buf, len);
+ u32 sum, l0;
+ u32 MagicS = 0x4b544d47;
+ u32 MagicE = 0x4e525241;
+ if (*((u32 *) buf) == MagicS) {
+ fprintf(stderr,
+ "Image without extra 8 bytes - Standard header\n");
+ *((u32 *) (buf + 0x10)) = len;
+ lseek(fd, 0x10, SEEK_SET);
+ write(fd, buf + 0x10, 0x4);
+ EHDR = 0;
+ } else if ((*((u32 *) (buf + 0x8)) == MagicS)
+ && ((*((u32 *) (buf + 0x4)) == MagicE))) {
+ fprintf(stderr,
+ "Image with extra 8 bytes - Extended header\n");
+ *((u32 *) (buf + 0x18)) = len - 8;
+ lseek(fd, 0x18, SEEK_SET);
+ write(fd, buf + 0x18, 0x4);
+ buf += 8;
+ EHDR = 1;
+ } else if (len == *((u32 *) (buf + 0x10))) {
+ fprintf(stderr,
+ "Image without extra 8 bytes - Standard header\n");
+ EHDR = 0;
+ } else if (len == *((u32 *) (buf + 0x18)) + 8) {
+ fprintf(stderr,
+ "Image with extra 8 bytes - Extended header\n");
+ buf += 8;
+ EHDR = 1;
+ } else {
+ fprintf(stderr, "ERROR: Wrong image size\n");
+ exit(-1);
+ }
+ l0 = *((u32 *) & buf[0x10]);
+ if (!BHDR)
+ *((u32 *) & buf[0x18]) = 0;
+ ulong sum0 = *((u32 *) & buf[0x18]);
+ ulong sum1 = *((u32 *) & buf[0x4]);
+ *((u32 *) & buf[0x4]) = 0x0L;
+ for (i = 0; i < 0x100; i++)
+ b[i] = buf[i];
+ for (i = 0; i < 0x100; i++)
+ b[0x100 + i] = buf[(l0 >> 1) + i];
+ for (i = 0; i < 0x200; i++)
+ b[0x200 + i] = buf[l0 - 0x200 + i];
+ *((u32 *) & b[0x18]) = 0x0L;
+
+ sum = crc32(b, 0x400);
+ printf("CRC32 sum0 - (%x, %x, %x)\n", sum, sum0, 0x400);
+ if (EHDR)
+ lseek(fd, 0x20, SEEK_SET);
+ else
+ lseek(fd, 0x18, SEEK_SET);
+ if (BHDR)
+ *((u32 *) & buf[0x18]) = sum;
+ else
+ *((u32 *) & buf[0x18]) = sum0;
+ write(fd, &buf[0x18], 0x4);
+
+ sum = crc32(buf, l0);
+ printf("CRC32 sum1 - (%x, %x, %x)\n", sum, sum1, l0);
+ if (EHDR)
+ lseek(fd, 0xC, SEEK_SET);
+ else
+ lseek(fd, 0x4, SEEK_SET);
+ *((u32 *) & buf[0x4]) = sum;
+ write(fd, &buf[0x4], 0x4);
+ if (EHDR) {
+ ulong sum2 = *((u32 *) & buf[-0x8]);
+ *((u32 *) & buf[-0x8]) = 0L;
+ sum = crc32(buf - 0x4, len - 0x4);
+ sum = htonl(sum);
+ printf("CRC32 sum2 - (%x, %x, %x)\n", sum, sum2,
+ len - 0x4);
+ lseek(fd, 0, SEEK_SET);
+ *((u32 *) & buf[-0x8]) = sum;
+ write(fd, &buf[-0x8], 0x4);
+ buf -= 8;
+ }
+ close(fd);
+ free(buf);
+ return 0;
+}