2 * Copyright (C) 2015 Thomas Hebb <tommyhebb@gmail.com>
4 * The format of the header this tool generates was first documented by
5 * Chris Blake <chrisrblake93 (at) gmail.com> in a shell script of the
6 * same purpose. I have created this reimplementation at his request. The
7 * original script can be found at:
8 * <https://github.com/riptidewave93/meraki-partbuilder>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published
12 * by the Free Software Foundation.
23 #include <arpa/inet.h>
27 #define PADDING_BYTE 0xff
29 #define HDR_LENGTH 0x00000400
30 #define HDR_OFF_MAGIC1 0
31 #define HDR_OFF_HDRLEN 4
32 #define HDR_OFF_IMAGELEN 8
33 #define HDR_OFF_CHECKSUM 12
34 #define HDR_OFF_MAGIC2 32
35 #define HDR_OFF_MAGIC3 36
36 #define HDR_OFF_STATICHASH 40
37 #define HDR_OFF_KERNEL_OFFSET 40
38 #define HDR_OFF_RAMDISK_OFFSET 44
39 #define HDR_OFF_FDT_OFFSET 48
40 #define HDR_OFF_UNKNOWN_OFFSET 52
48 unsigned char statichash[20];
50 uint32_t kernel_offset;
51 uint32_t ramdisk_offset;
53 uint32_t unknown_offset;
63 static char *progname;
65 static char *board_id;
66 static const struct board_info *board;
68 static const struct board_info boards[] = {
71 .description = "Meraki MR18 Access Point",
74 .imagelen = 0x00800000,
75 .u.statichash = {0xda, 0x39, 0xa3, 0xee, 0x5e,
76 0x6b, 0x4b, 0x0d, 0x32, 0x55,
77 0xbf, 0xef, 0x95, 0x60, 0x18,
78 0x90, 0xaf, 0xd8, 0x07, 0x09},
81 .description = "Meraki MR24 Access Point",
84 .imagelen = 0x00800000,
85 .u.statichash = {0xff, 0xff, 0xff, 0xff, 0xff,
86 0xff, 0xff, 0xff, 0xff, 0xff,
87 0xff, 0xff, 0xff, 0xff, 0xff,
88 0xff, 0xff, 0xff, 0xff, 0xff},
91 .description = "Meraki MX60/MX60W Security Appliance",
93 .magic2 = 0xa1f0beef, /* Enables use of load addr in statichash */
94 .magic3 = 0x00060001, /* This goes along with magic2 */
95 .imagelen = 0x3fd00000,
96 /* The static hash below does the following:
97 * 1st Row: Kernel Offset
98 * 2nd Row: Ramdisk Offset
100 * 4th Row: ? Unused/Unknown ?
101 * 5th Row: ? Unused/Unknown ?
104 .kernel_offset = 0x10000,
105 .ramdisk_offset = 0x3FFC00,
106 .fdt_offset = 0x0400,
107 .unknown_offset = 0x0400,
110 /* terminating entry */
117 #define ERR(fmt, ...) do { \
119 fprintf(stderr, "[%s] *** error: " fmt "\n", \
120 progname, ## __VA_ARGS__); \
123 #define ERRS(fmt, ...) do { \
126 fprintf(stderr, "[%s] *** error: " fmt "\n", \
127 progname, ## __VA_ARGS__, strerror(save)); \
130 static const struct board_info *find_board(const char *id)
132 const struct board_info *ret;
133 const struct board_info *board;
136 for (board = boards; board->id != NULL; board++) {
137 if (strcasecmp(id, board->id) == 0) {
146 static void usage(int status)
148 FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
149 const struct board_info *board;
151 fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
155 " -B <board> create image for the board specified with <board>\n"
156 " -i <file> read kernel image from the file <file>\n"
157 " -o <file> write output to the file <file>\n"
158 " -s strip padding from the end of the image\n"
159 " -h show this screen\n"
162 fprintf(stream, "\nBoards:\n");
163 for (board = boards; board->id != NULL; board++)
164 fprintf(stream, " %-16s%s\n", board->id, board->description);
169 void writel(unsigned char *buf, size_t offset, uint32_t value)
171 value = htonl(value);
172 memcpy(buf + offset, &value, sizeof(uint32_t));
175 int main(int argc, char *argv[])
177 int ret = EXIT_FAILURE;
180 unsigned char *kernel;
183 bool strip_padding = false;
184 char *ofname = NULL, *ifname = NULL;
187 progname = basename(argv[0]);
192 c = getopt(argc, argv, "B:i:o:sh");
207 strip_padding = true;
218 if (board_id == NULL) {
219 ERR("no board specified");
223 board = find_board(board_id);
225 ERR("unknown board \"%s\"", board_id);
229 if (ifname == NULL) {
230 ERR("no input file specified");
234 if (ofname == NULL) {
235 ERR("no output file specified");
239 in = fopen(ifname, "r");
241 ERRS("could not open \"%s\" for reading: %s", ifname);
245 buflen = board->imagelen;
246 kspace = buflen - HDR_LENGTH;
248 /* Get kernel length */
249 fseek(in, 0, SEEK_END);
254 ERR("file \"%s\" is too big - max size: 0x%08lX\n",
259 /* If requested, resize buffer to remove padding */
261 buflen = klen + HDR_LENGTH;
263 /* Allocate and initialize buffer for final image */
264 buf = malloc(buflen);
266 ERRS("no memory for buffer: %s\n");
269 memset(buf, PADDING_BYTE, buflen);
272 kernel = buf + HDR_LENGTH;
273 fread(kernel, klen, 1, in);
275 /* Write magic values */
276 writel(buf, HDR_OFF_MAGIC1, board->magic1);
277 writel(buf, HDR_OFF_MAGIC2, board->magic2);
278 writel(buf, HDR_OFF_MAGIC3, board->magic3);
280 /* Write header and image length */
281 writel(buf, HDR_OFF_HDRLEN, HDR_LENGTH);
282 writel(buf, HDR_OFF_IMAGELEN, klen);
284 /* Write checksum and static hash */
285 sha1_csum(kernel, klen, buf + HDR_OFF_CHECKSUM);
287 switch (board->magic2) {
289 writel(buf, HDR_OFF_KERNEL_OFFSET, board->u.mx60.kernel_offset);
290 writel(buf, HDR_OFF_RAMDISK_OFFSET, board->u.mx60.ramdisk_offset);
291 writel(buf, HDR_OFF_FDT_OFFSET, board->u.mx60.fdt_offset),
292 writel(buf, HDR_OFF_UNKNOWN_OFFSET, board->u.mx60.unknown_offset);
296 memcpy(buf + HDR_OFF_STATICHASH, board->u.statichash, 20);
300 /* Save finished image */
301 out = fopen(ofname, "w");
303 ERRS("could not open \"%s\" for writing: %s", ofname);
306 fwrite(buf, buflen, 1, out);