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)
38 uint32_t kernel_chksum;
39 uint32_t rootfs_chksum;
42 uint32_t image_chksum;
43 uint32_t header_chksum;
44 /* char board_id[] - upto MAX_BOARD_ID_LEN */
47 static void __attribute__ ((format (printf, 2, 3)))
48 fatal_error (int maybe_errno, const char * format, ...)
52 fprintf (stderr, "mkchkimg: ");
53 va_start (ap, format);
54 vfprintf (stderr, format, ap);
58 fprintf (stderr, ": %s\n", strerror (maybe_errno));
60 fprintf (stderr, "\n");
66 static void __attribute__ ((format (printf, 1, 2)))
67 message (const char * format, ...)
71 fprintf (stderr, "mkchkimg: ");
72 va_start (ap, format);
73 vfprintf (stderr, format, ap);
75 fprintf (stderr, "\n");
84 netgear_checksum_init (struct ngr_checksum * c)
90 netgear_checksum_add (struct ngr_checksum * c, unsigned char * buf, size_t len)
94 for (i=0; i<len; i++) {
95 c->c0 += buf[i] & 0xff;
100 static inline unsigned long
101 netgear_checksum_fini (struct ngr_checksum * c)
103 uint32_t b, checksum;
105 b = (c->c0 & 65535) + ((c->c0 >> 16) & 65535);
106 c->c0 = ((b >> 16) + b) & 65535;
107 b = (c->c1 & 65535) + ((c->c1 >> 16) & 65535);
108 c->c1 = ((b >> 16) + b) & 65535;
109 checksum = ((c->c1 << 16) | c->c0);
116 fprintf (stderr, "Usage: mkchkimg -o output -k kernel [-f filesys] [-b board_id] [-r region]\n");
120 main (int argc, char * argv[])
126 struct chk_header * hdr;
127 struct ngr_checksum chk_part, chk_whole;
129 char * output_file, * kern_file, * fs_file;
130 FILE * out_fp, * kern_fp, * fs_fp;
132 unsigned long region;
135 board_id = "U12H072T00_NETGEAR";
136 region = 1; /* 1=WW, 2=NA */
142 while ((opt = getopt (argc, argv, ":b:r:k:f:o:h")) != -1) {
146 if (strlen (optarg) > MAX_BOARD_ID_LEN) {
147 fatal_error (0, "Board lenght exceeds %d",
156 region = strtoul (optarg, &ptr, 0);
157 if (errno || ptr==optarg || *ptr!='\0') {
158 fatal_error (0, "Cannot parse region %s", optarg);
161 fatal_error (0, "Region cannot exceed 0xff");
177 output_file = optarg;
186 fatal_error (0, "Option -%c missing argument", optopt);
191 fatal_error (0, "Unknown argument -%c", optopt);
199 /* Check we have all the options expected */
202 fatal_error (0, "Kernel file expected");
206 fatal_error (0, "Output file required");
208 message ("Netgear CHK writer - v0.1");
210 /* Open the input file */
211 kern_fp = fopen (kern_file, "r");
213 fatal_error (errno, "Cannot open %s", kern_file);
216 /* Open the fs file, if specified */
218 fs_fp = fopen (fs_file, "r");
220 fatal_error (errno, "Cannot open %s", fs_file);
224 /* Open the output file */
225 out_fp = fopen (output_file, "w+");
227 fatal_error (errno, "Cannot open %s", output_file);
230 /* Write zeros when the chk header will be */
232 header_len = sizeof (struct chk_header) + strlen (board_id);
233 if (fwrite (buf, 1, header_len, out_fp) != header_len) {
234 fatal_error (errno, "Cannot write header");
237 /* Allocate storage for header, we fill in as we go */
238 hdr = malloc (sizeof (struct chk_header));
240 fatal_error (0, "malloc failed");
242 bzero (hdr, sizeof (struct chk_header));
244 /* Fill in known values */
245 hdr->magic = htonl (0x2a23245e);
246 hdr->header_len = htonl(header_len);
247 hdr->reserved[0] = (unsigned char)(region & 0xff);
248 hdr->reserved[1] = 1; /* Major */
249 hdr->reserved[2] = 1; /* Minor */
250 hdr->reserved[3] = 99; /* Build */
251 hdr->reserved[4] = 0; /* Unknown t1 ? was 1 */
252 hdr->reserved[5] = 0; /* Unknonw t2 ? was 0 */
253 hdr->reserved[6] = 0; /* Unknonw t3 ? was 1 */
254 hdr->reserved[7] = 0; /* Unused ? */
255 message (" Board Id: %s", board_id);
256 message (" Region: %s", region == 1 ? "World Wide (WW)"
257 : (region == 2 ? "North America (NA)" : "Unknown"));
259 /* Copy the trx file, calculating the checksum as we go */
260 netgear_checksum_init (&chk_part);
261 netgear_checksum_init (&chk_whole);
262 while (!feof (kern_fp)) {
263 len = fread (buf, 1, BUF_LEN, kern_fp);
267 if (fwrite (buf, len, 1, out_fp) != 1) {
268 fatal_error (errno, "Write error");
270 hdr->kernel_len += len;
271 netgear_checksum_add (&chk_part, (unsigned char *)buf, len);
272 netgear_checksum_add (&chk_whole, (unsigned char *)buf, len);
274 hdr->kernel_chksum = netgear_checksum_fini (&chk_part);
275 message (" Kernel Len: %u", hdr->kernel_len);
276 message ("Kernel Checksum: 0x%08x", hdr->kernel_chksum);
277 hdr->kernel_len = htonl (hdr->kernel_len);
278 hdr->kernel_chksum = htonl (hdr->kernel_chksum);
280 /* Now copy the root fs, calculating the checksum as we go */
282 netgear_checksum_init (&chk_part);
283 while (!feof (fs_fp)) {
284 len = fread (buf, 1, BUF_LEN, fs_fp);
288 if (fwrite (buf, len, 1, out_fp) != 1) {
289 fatal_error (errno, "Write error");
291 hdr->rootfs_len += len;
292 netgear_checksum_add (&chk_part, (unsigned char *)buf, len);
293 netgear_checksum_add (&chk_whole, (unsigned char *)buf, len);
295 hdr->rootfs_chksum = (netgear_checksum_fini (&chk_part));
296 message (" Rootfs Len: %u", hdr->rootfs_len);
297 message ("Rootfs Checksum: 0x%08x", hdr->rootfs_chksum);
298 hdr->rootfs_len = htonl (hdr->rootfs_len);
299 hdr->rootfs_chksum = htonl (hdr->rootfs_chksum);
302 /* Calcautate the image checksum */
303 hdr->image_chksum = netgear_checksum_fini (&chk_whole);
304 message (" Image Checksum: 0x%08x", hdr->image_chksum);
305 hdr->image_chksum = htonl (hdr->image_chksum);
307 /* Calculate the header checksum */
308 netgear_checksum_init (&chk_part);
309 netgear_checksum_add (&chk_part, (unsigned char *)hdr,
310 sizeof (struct chk_header));
311 netgear_checksum_add (&chk_part, (unsigned char *)board_id,
313 hdr->header_chksum = htonl (netgear_checksum_fini (&chk_part));
315 /* Finally rewind the output and write headers */
317 if (fwrite (hdr, sizeof (struct chk_header), 1, out_fp) != 1) {
318 fatal_error (errno, "Cannot write header");
320 if (fwrite (board_id, strlen (board_id), 1, out_fp) != 1) {
321 fatal_error (errno, "Cannot write board id");