7812eb9b39d205fd14facbe8ccd9c6033b1dc0c8
[openwrt/staging/chunkeey.git] / tools / patch-image / src / patch-dtb.c
1 /*
2 * patch-dtb.c - patch a dtb into an image
3 *
4 * Copyright (C) 2006 Felix Fietkau <nbd@nbd.name>
5 * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 * based on patch-cmdline.c
22 */
23
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <stddef.h>
27 #include <unistd.h>
28 #include <fcntl.h>
29 #include <sys/mman.h>
30 #include <sys/stat.h>
31 #include <string.h>
32
33 #define SEARCH_SPACE (16 * 1024)
34 #define DTB_MAX (16 * 1024)
35
36 int main(int argc, char **argv)
37 {
38 int fd, fddtb, found = 0, len, ret = -1;
39 char *ptr, *ptrdtb, *p;
40 struct stat s;
41
42 if (argc != 3) {
43 fprintf(stderr, "Usage: %s <file> <dtb>\n", argv[0]);
44 goto err1;
45 }
46 fddtb = open(argv[1], O_RDONLY);
47 if (!fddtb)
48 goto err1;
49
50 if (stat(argv[2], &s)) {
51 fprintf(stderr, "DTB not found\n");
52 goto err1;
53 }
54
55 len = s.st_size;
56 if (len + 8 > DTB_MAX) {
57 fprintf(stderr, "DTB too big\n");
58 goto err1;
59 }
60
61 if (((fddtb = open(argv[2], O_RDONLY)) < 0) ||
62 (ptrdtb = (char *) mmap(0, DTB_MAX, PROT_READ, MAP_SHARED, fddtb, 0)) == (void *) (-1)) {
63 fprintf(stderr, "Could not open DTB");
64 goto err2;
65 }
66
67 if (((fd = open(argv[1], O_RDWR)) < 0) ||
68 (ptr = (char *) mmap(0, SEARCH_SPACE + DTB_MAX, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1)) {
69 fprintf(stderr, "Could not open kernel image");
70 goto err3;
71 }
72
73 for (p = ptr; p < (ptr + SEARCH_SPACE); p += 4) {
74 if (memcmp(p, "OWRTDTB:", 8) == 0) {
75 found = 1;
76 p += 8;
77 break;
78 }
79 }
80 if (!found) {
81 fprintf(stderr, "DTB marker not found!\n");
82 goto err4;
83 }
84
85 memset(p, 0, DTB_MAX - 8);
86 memcpy(p, ptrdtb, len);
87 msync(p, len, MS_SYNC|MS_INVALIDATE);
88 ret = 0;
89
90 err4:
91 munmap((void *) ptr, len);
92 err3:
93 if (fd > 0)
94 close(fd);
95 munmap((void *) ptrdtb, len);
96 err2:
97 if (fddtb > 0)
98 close(fddtb);
99 err1:
100 return ret;
101 }