4 * This utility creates Netgear .chk files.
6 * Copyright (C) 2008 Dave C. Reeve <Dave.Reeve@dreeve.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <arpa/inet.h>
30 #define BUF_LEN (2048)
32 #define MAX_BOARD_ID_LEN (64)
35 * Note on the reserved field of the chk_header:
36 * OFW naming scheme is typically: DEVICENAME-VA.B.C.D_E.F.G.chk, with A-G
37 * between 0 and 255. For instance: EX3700_EX3800-V1.0.0.58_1.0.38.chk
38 * The reserved field works like this:
39 * reserved[0]: region code. 1 for WW (WorldWide) and 2 for NA (North America)
52 uint32_t kernel_chksum;
53 uint32_t rootfs_chksum;
56 uint32_t image_chksum;
57 uint32_t header_chksum;
58 /* char board_id[] - upto MAX_BOARD_ID_LEN */
61 static void __attribute__ ((format (printf, 2, 3)))
62 fatal_error (int maybe_errno, const char * format, ...)
66 fprintf (stderr, "mkchkimg: ");
67 va_start (ap, format);
68 vfprintf (stderr, format, ap);
72 fprintf (stderr, ": %s\n", strerror (maybe_errno));
74 fprintf (stderr, "\n");
80 static void __attribute__ ((format (printf, 1, 2)))
81 message (const char * format, ...)
85 fprintf (stderr, "mkchkimg: ");
86 va_start (ap, format);
87 vfprintf (stderr, format, ap);
89 fprintf (stderr, "\n");
98 netgear_checksum_init (struct ngr_checksum * c)
104 netgear_checksum_add (struct ngr_checksum * c, unsigned char * buf, size_t len)
108 for (i=0; i<len; i++) {
109 c->c0 += buf[i] & 0xff;
114 static inline unsigned long
115 netgear_checksum_fini (struct ngr_checksum * c)
117 uint32_t b, checksum;
119 b = (c->c0 & 65535) + ((c->c0 >> 16) & 65535);
120 c->c0 = ((b >> 16) + b) & 65535;
121 b = (c->c1 & 65535) + ((c->c1 >> 16) & 65535);
122 c->c1 = ((b >> 16) + b) & 65535;
123 checksum = ((c->c1 << 16) | c->c0);
130 fprintf (stderr, "Usage: mkchkimg -o output -k kernel [-f filesys] [-b board_id] [-r region]\n");
134 main (int argc, char * argv[])
140 struct chk_header * hdr;
141 struct ngr_checksum chk_part, chk_whole;
143 char * output_file, * kern_file, * fs_file;
144 FILE * out_fp, * kern_fp, * fs_fp;
146 unsigned long region;
149 board_id = "U12H072T00_NETGEAR";
150 region = 1; /* 1=WW, 2=NA */
156 while ((opt = getopt (argc, argv, ":b:r:k:f:o:h")) != -1) {
160 if (strlen (optarg) > MAX_BOARD_ID_LEN) {
161 fatal_error (0, "Board lenght exceeds %d",
170 region = strtoul (optarg, &ptr, 0);
171 if (errno || ptr==optarg || *ptr!='\0') {
172 fatal_error (0, "Cannot parse region %s", optarg);
175 fatal_error (0, "Region cannot exceed 0xff");
191 output_file = optarg;
200 fatal_error (0, "Option -%c missing argument", optopt);
205 fatal_error (0, "Unknown argument -%c", optopt);
213 /* Check we have all the options expected */
216 fatal_error (0, "Kernel file expected");
220 fatal_error (0, "Output file required");
222 message ("Netgear CHK writer - v0.1");
224 /* Open the input file */
225 kern_fp = fopen (kern_file, "r");
227 fatal_error (errno, "Cannot open %s", kern_file);
230 /* Open the fs file, if specified */
232 fs_fp = fopen (fs_file, "r");
234 fatal_error (errno, "Cannot open %s", fs_file);
238 /* Open the output file */
239 out_fp = fopen (output_file, "w+");
241 fatal_error (errno, "Cannot open %s", output_file);
244 /* Write zeros when the chk header will be */
246 header_len = sizeof (struct chk_header) + strlen (board_id);
247 if (fwrite (buf, 1, header_len, out_fp) != header_len) {
248 fatal_error (errno, "Cannot write header");
251 /* Allocate storage for header, we fill in as we go */
252 hdr = malloc (sizeof (struct chk_header));
254 fatal_error (0, "malloc failed");
256 bzero (hdr, sizeof (struct chk_header));
258 /* Fill in known values */
259 hdr->magic = htonl (0x2a23245e);
260 hdr->header_len = htonl(header_len);
261 hdr->reserved[0] = (unsigned char)(region & 0xff);
262 hdr->reserved[1] = 1; /* Major */
263 hdr->reserved[2] = 1; /* Minor */
264 hdr->reserved[3] = 99; /* Build */
265 hdr->reserved[4] = 0;
266 hdr->reserved[5] = 0;
267 hdr->reserved[6] = 0;
268 hdr->reserved[7] = 0;
269 message (" Board Id: %s", board_id);
270 message (" Region: %s", region == 1 ? "World Wide (WW)"
271 : (region == 2 ? "North America (NA)" : "Unknown"));
273 /* Copy the trx file, calculating the checksum as we go */
274 netgear_checksum_init (&chk_part);
275 netgear_checksum_init (&chk_whole);
276 while (!feof (kern_fp)) {
277 len = fread (buf, 1, BUF_LEN, kern_fp);
281 if (fwrite (buf, len, 1, out_fp) != 1) {
282 fatal_error (errno, "Write error");
284 hdr->kernel_len += len;
285 netgear_checksum_add (&chk_part, (unsigned char *)buf, len);
286 netgear_checksum_add (&chk_whole, (unsigned char *)buf, len);
288 hdr->kernel_chksum = netgear_checksum_fini (&chk_part);
289 message (" Kernel Len: %u", hdr->kernel_len);
290 message ("Kernel Checksum: 0x%08x", hdr->kernel_chksum);
291 hdr->kernel_len = htonl (hdr->kernel_len);
292 hdr->kernel_chksum = htonl (hdr->kernel_chksum);
294 /* Now copy the root fs, calculating the checksum as we go */
296 netgear_checksum_init (&chk_part);
297 while (!feof (fs_fp)) {
298 len = fread (buf, 1, BUF_LEN, fs_fp);
302 if (fwrite (buf, len, 1, out_fp) != 1) {
303 fatal_error (errno, "Write error");
305 hdr->rootfs_len += len;
306 netgear_checksum_add (&chk_part, (unsigned char *)buf, len);
307 netgear_checksum_add (&chk_whole, (unsigned char *)buf, len);
309 hdr->rootfs_chksum = (netgear_checksum_fini (&chk_part));
310 message (" Rootfs Len: %u", hdr->rootfs_len);
311 message ("Rootfs Checksum: 0x%08x", hdr->rootfs_chksum);
312 hdr->rootfs_len = htonl (hdr->rootfs_len);
313 hdr->rootfs_chksum = htonl (hdr->rootfs_chksum);
316 /* Calcautate the image checksum */
317 hdr->image_chksum = netgear_checksum_fini (&chk_whole);
318 message (" Image Checksum: 0x%08x", hdr->image_chksum);
319 hdr->image_chksum = htonl (hdr->image_chksum);
321 /* Calculate the header checksum */
322 netgear_checksum_init (&chk_part);
323 netgear_checksum_add (&chk_part, (unsigned char *)hdr,
324 sizeof (struct chk_header));
325 netgear_checksum_add (&chk_part, (unsigned char *)board_id,
327 hdr->header_chksum = htonl (netgear_checksum_fini (&chk_part));
329 /* Finally rewind the output and write headers */
331 if (fwrite (hdr, sizeof (struct chk_header), 1, out_fp) != 1) {
332 fatal_error (errno, "Cannot write header");
334 if (fwrite (board_id, strlen (board_id), 1, out_fp) != 1) {
335 fatal_error (errno, "Cannot write board id");