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-rw-r--r--tools/firmware-utils/src/mkbrnimg.c189
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;
+}