diff options
Diffstat (limited to 'tools/firmware-utils/src/mkbrnimg.c')
| -rw-r--r-- | tools/firmware-utils/src/mkbrnimg.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/tools/firmware-utils/src/mkbrnimg.c b/tools/firmware-utils/src/mkbrnimg.c new file mode 100644 index 0000000..b7a73ff --- /dev/null +++ b/tools/firmware-utils/src/mkbrnimg.c @@ -0,0 +1,189 @@ +/* + * mkbrnimg.c - partially based on OpenWrt's wndr3700.c + * + * Copyright (C) 2011 Tobias Diedrich <ranma+openwrt@tdiedrich.de> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License, + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <string.h> +#include <netinet/in.h> +#include <inttypes.h> + +#define BPB 8 /* bits/byte */ + +static uint32_t crc32[1<<BPB]; + +static char *output_file = "default-brnImage"; +static uint32_t magic = 0x12345678; +static char *signature = "BRNDTW502"; +static uint32_t crc32_poly = 0x2083b8ed; + +static void init_crc32() +{ + const uint32_t poly = ntohl(crc32_poly); + int n; + + for (n = 0; n < 1<<BPB; n++) { + uint32_t crc = n; + int bit; + + for (bit = 0; bit < BPB; bit++) + crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1); + crc32[n] = crc; + } +} + +static uint32_t crc32buf(unsigned char *buf, size_t len) +{ + uint32_t crc = 0xFFFFFFFF; + + for (; len; len--, buf++) + crc = crc32[(uint8_t)crc ^ *buf] ^ (crc >> BPB); + return ~crc; +} + +static void usage(const char *) __attribute__ (( __noreturn__ )); + +static void usage(const char *mess) +{ + fprintf(stderr, "Error: %s\n", mess); + fprintf(stderr, "Usage: mkbrnimg [-o output_file] [-m magic] [-s signature] [-p crc32 poly] kernel_file [additional files]\n"); + fprintf(stderr, "\n"); + exit(1); +} + +static void parseopts(int *argc, char ***argv) +{ + char *endptr; + int res; + + while ((res = getopt(*argc, *argv, "o:m:s:p:")) != -1) { + switch (res) { + default: + usage("Unknown option"); + break; + case 'o': + output_file = optarg; + break; + case 'm': + magic = strtoul(optarg, &endptr, 0); + if (endptr == optarg || *endptr != 0) + usage("magic must be a decimal or hexadecimal 32-bit value"); + break; + case 's': + signature = optarg; + break; + case 'p': + crc32_poly = strtoul(optarg, &endptr, 0); + if (endptr == optarg || *endptr != 0) + usage("'crc32 poly' must be a decimal or hexadecimal 32-bit value"); + break; + } + } + *argc -= optind; + *argv += optind; +} + +static void appendfile(int outfd, char *path, int kernel) { + int fd; + size_t len, padded_len; + char *input_file; + uint32_t crc; + char padding[0x400]; + char footer[12]; + + memset(padding, 0xff, sizeof(padding)); + + // mmap input_file + if ((fd = open(path, O_RDONLY)) < 0 + || (len = lseek(fd, 0, SEEK_END)) < 0 + || (input_file = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)) == (void *) (-1) + || close(fd) < 0) + { + fprintf(stderr, "Error mapping file '%s': %s\n", path, strerror(errno)); + exit(1); + } + + // kernel should be lzma compressed image, not uImage + if (kernel && + (input_file[0] != (char)0x5d || + input_file[1] != (char)0x00 || + input_file[2] != (char)0x00 || + input_file[3] != (char)0x80)) { + fprintf(stderr, "lzma signature not found on kernel image.\n"); + exit(1); + } + + init_crc32(); + crc = crc32buf(input_file, len); + fprintf(stderr, "crc32 for '%s' is %08x.\n", path, crc); + + // write the file + write(outfd, input_file, len); + + // write padding + padded_len = ((len + sizeof(footer) + sizeof(padding) - 1) & ~(sizeof(padding) - 1)) - sizeof(footer); + fprintf(stderr, "len=%08zx padded_len=%08zx\n", len, padded_len); + write(outfd, padding, padded_len - len); + + // write footer + footer[0] = (len >> 0) & 0xff; + footer[1] = (len >> 8) & 0xff; + footer[2] = (len >> 16) & 0xff; + footer[3] = (len >> 24) & 0xff; + footer[4] = (magic >> 0) & 0xff; + footer[5] = (magic >> 8) & 0xff; + footer[6] = (magic >> 16) & 0xff; + footer[7] = (magic >> 24) & 0xff; + footer[8] = (crc >> 0) & 0xff; + footer[9] = (crc >> 8) & 0xff; + footer[10] = (crc >> 16) & 0xff; + footer[11] = (crc >> 24) & 0xff; + write(outfd, footer, sizeof(footer)); + + munmap(input_file, len); +} + +int main(int argc, char **argv) +{ + int outfd; + int i; + + parseopts(&argc, &argv); + + if (argc < 1) + usage("wrong number of arguments"); + + if ((outfd = open(output_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1) + { + fprintf(stderr, "Error opening '%s' for writing: %s\n", output_file, strerror(errno)); + exit(1); + } + + for (i=0; i<argc; i++) { + appendfile(outfd, argv[i], i == 0); + } + write(outfd, signature, strlen(signature)+1); + close(outfd); + + return 0; +} |