firmware-utils mkmerakifw: firmware generator for MR18
authorJohn Crispin <john@openwrt.org>
Fri, 11 Dec 2015 15:06:45 +0000 (15:06 +0000)
committerJohn Crispin <john@openwrt.org>
Fri, 11 Dec 2015 15:06:45 +0000 (15:06 +0000)
This patch adds firmware generation tool for Cisco's MR18

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
SVN-Revision: 47856

tools/firmware-utils/Makefile
tools/firmware-utils/src/mkmerakifw.c [new file with mode: 0644]

index bd69cb4..dc922b0 100644 (file)
@@ -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 (file)
index 0000000..241bb33
--- /dev/null
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2015 Thomas Hebb <tommyhebb@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;
+}