[OpenWrt-Devel] [RFC 3/5] firmware-utils mkmerakifw: firmware generator for MR18
Thomas Hebb
chunkeey at googlemail.com
Thu Sep 17 11:27:05 EDT 2015
From: Thomas Hebb <tommyhebb at gmail.com>
This patch adds firmware generation tool for Cisco's MR18
Signed-off-by: Thomas Hebb <tommyhebb at gmail.com>
---
tools/firmware-utils/Makefile | 1 +
tools/firmware-utils/src/mkmerakifw.c | 263 ++++++++++++++++++++++++++++++++++
2 files changed, 264 insertions(+)
create mode 100644 tools/firmware-utils/src/mkmerakifw.c
diff --git a/tools/firmware-utils/Makefile b/tools/firmware-utils/Makefile
index bd69cb4..dc922b0 100644
--- a/tools/firmware-utils/Makefile
+++ b/tools/firmware-utils/Makefile
@@ -73,6 +73,7 @@ define Host/Compile
$(call cc,mkrtn56uimg, -lz)
$(call cc,dgn3500sum)
$(call cc,edimax_fw_header, -Wall)
+ $(call cc,mkmerakifw sha1, -Wall)
endef
define Host/Install
diff --git a/tools/firmware-utils/src/mkmerakifw.c b/tools/firmware-utils/src/mkmerakifw.c
new file mode 100644
index 0000000..241bb33
--- /dev/null
+++ b/tools/firmware-utils/src/mkmerakifw.c
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2015 Thomas Hebb <tommyhebb at gmail.com>
+ *
+ * The format of the header this tool generates was first documented by
+ * Chris Blake <chrisrblake93 (at) gmail.com> in a shell script of the
+ * same purpose. I have created this reimplementation at his request. The
+ * original script can be found at:
+ * <https://github.com/riptidewave93/meraki-partbuilder>
+ *
+ * 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.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <libgen.h>
+#include <getopt.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include "sha1.h"
+
+#define PADDING_BYTE 0xff
+
+#define HDR_LENGTH 0x00000400
+#define HDR_OFF_MAGIC1 0
+#define HDR_OFF_HDRLEN 4
+#define HDR_OFF_IMAGELEN 8
+#define HDR_OFF_CHECKSUM 12
+#define HDR_OFF_MAGIC2 32
+#define HDR_OFF_FILLER 36
+#define HDR_OFF_STATICHASH 40
+
+struct board_info {
+ uint32_t magic;
+ uint32_t imagelen;
+ unsigned char statichash[20];
+ char *id;
+ char *description;
+};
+
+/*
+ * Globals
+ */
+static char *progname;
+
+static char *board_id;
+static const struct board_info *board;
+
+static const struct board_info boards[] = {
+ {
+ .id = "mr18",
+ .description = "Meraki MR18 Access Point",
+ .magic = 0x8e73ed8a,
+ .imagelen = 0x00800000,
+ .statichash = {0xda, 0x39, 0xa3, 0xee, 0x5e,
+ 0x6b, 0x4b, 0x0d, 0x32, 0x55,
+ 0xbf, 0xef, 0x95, 0x60, 0x18,
+ 0x90, 0xaf, 0xd8, 0x07, 0x09},
+ }, {
+ /* terminating entry */
+ }
+};
+
+/*
+ * Message macros
+ */
+#define ERR(fmt, ...) do { \
+ fflush(0); \
+ fprintf(stderr, "[%s] *** error: " fmt "\n", \
+ progname, ## __VA_ARGS__); \
+} while (0)
+
+#define ERRS(fmt, ...) do { \
+ int save = errno; \
+ fflush(0); \
+ fprintf(stderr, "[%s] *** error: " fmt "\n", \
+ progname, ## __VA_ARGS__, strerror(save)); \
+} while (0)
+
+static const struct board_info *find_board(const char *id)
+{
+ const struct board_info *ret;
+ const struct board_info *board;
+
+ ret = NULL;
+ for (board = boards; board->id != NULL; board++) {
+ if (strcasecmp(id, board->id) == 0) {
+ ret = board;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static void usage(int status)
+{
+ FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
+ const struct board_info *board;
+
+ fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
+ fprintf(stream,
+"\n"
+"Options:\n"
+" -B <board> create image for the board specified with <board>\n"
+" -i <file> read kernel image from the file <file>\n"
+" -o <file> write output to the file <file>\n"
+" -s strip padding from the end of the image\n"
+" -h show this screen\n"
+ );
+
+ fprintf(stream, "\nBoards:\n");
+ for (board = boards; board->id != NULL; board++)
+ fprintf(stream, " %-16s%s\n", board->id, board->description);
+
+ exit(status);
+}
+
+void writel(unsigned char *buf, size_t offset, uint32_t value)
+{
+ value = htonl(value);
+ memcpy(buf + offset, &value, sizeof(uint32_t));
+}
+
+int main(int argc, char *argv[])
+{
+ int ret = EXIT_FAILURE;
+ long klen;
+ size_t kspace;
+ unsigned char *kernel;
+ size_t buflen;
+ unsigned char *buf;
+ bool strip_padding = false;
+ char *ofname = NULL, *ifname = NULL;
+ FILE *out, *in;
+
+ progname = basename(argv[0]);
+
+ while (1) {
+ int c;
+
+ c = getopt(argc, argv, "B:i:o:sh");
+ if (c == -1)
+ break;
+
+ switch (c) {
+ case 'B':
+ board_id = optarg;
+ break;
+ case 'i':
+ ifname = optarg;
+ break;
+ case 'o':
+ ofname = optarg;
+ break;
+ case 's':
+ strip_padding = true;
+ break;
+ case 'h':
+ usage(EXIT_SUCCESS);
+ break;
+ default:
+ usage(EXIT_FAILURE);
+ break;
+ }
+ }
+
+ if (board_id == NULL) {
+ ERR("no board specified");
+ goto err;
+ }
+
+ board = find_board(board_id);
+ if (board == NULL) {
+ ERR("unknown board \"%s\"", board_id);
+ goto err;
+ }
+
+ if (ifname == NULL) {
+ ERR("no input file specified");
+ goto err;
+ }
+
+ if (ofname == NULL) {
+ ERR("no output file specified");
+ goto err;
+ }
+
+ in = fopen(ifname, "r");
+ if (in == NULL) {
+ ERRS("could not open \"%s\" for reading: %s", ifname);
+ goto err;
+ }
+
+ buflen = board->imagelen;
+ kspace = buflen - HDR_LENGTH;
+
+ /* Get kernel length */
+ fseek(in, 0, SEEK_END);
+ klen = ftell(in);
+ rewind(in);
+
+ if (klen > kspace) {
+ ERR("file \"%s\" is too big - max size: 0x%08lX\n",
+ ifname, kspace);
+ goto err_close_in;
+ }
+
+ /* If requested, resize buffer to remove padding */
+ if (strip_padding)
+ buflen = klen + HDR_LENGTH;
+
+ /* Allocate and initialize buffer for final image */
+ buf = malloc(buflen);
+ if (buf == NULL) {
+ ERRS("no memory for buffer: %s\n");
+ goto err_close_in;
+ }
+ memset(buf, PADDING_BYTE, buflen);
+
+ /* Load kernel */
+ kernel = buf + HDR_LENGTH;
+ fread(kernel, klen, 1, in);
+
+ /* Write magic values and filler */
+ writel(buf, HDR_OFF_MAGIC1, board->magic);
+ writel(buf, HDR_OFF_MAGIC2, board->magic);
+ writel(buf, HDR_OFF_FILLER, 0);
+
+ /* Write header and image length */
+ writel(buf, HDR_OFF_HDRLEN, HDR_LENGTH);
+ writel(buf, HDR_OFF_IMAGELEN, klen);
+
+ /* Write checksum and static hash */
+ sha1_csum(kernel, klen, buf + HDR_OFF_CHECKSUM);
+ memcpy(buf + HDR_OFF_STATICHASH, board->statichash, 20);
+
+ /* Save finished image */
+ out = fopen(ofname, "w");
+ if (out == NULL) {
+ ERRS("could not open \"%s\" for writing: %s", ofname);
+ goto err_free;
+ }
+ fwrite(buf, buflen, 1, out);
+
+ ret = EXIT_SUCCESS;
+
+ fclose(out);
+
+err_free:
+ free(buf);
+
+err_close_in:
+ fclose(in);
+
+err:
+ return ret;
+}
--
2.5.1
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