/*
* patch-dtb.c - patch a dtb into an image
*
* Copyright (C) 2006 Felix Fietkau <nbd@nbd.name>
* Copyright (C) 2012 John Crispin <blogic@openwrt.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* based on patch-cmdline.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <string.h>
#define DTB_MAX (16 * 1024)
int main(int argc, char **argv)
{
int fd, fddtb, found = 0, len, ret = -1;
char *ptr, *ptrdtb, *p;
struct stat s;
unsigned int search_space , dtb_max_size;
if (argc <= 2 || argc > 4) {
fprintf(stderr, "Usage: %s <file> <dtb> [size]\n", argv[0]);
goto err1;
} else if (argc == 3) {
fprintf(stdout, "DT size used is default of 16KB\n");
search_space = dtb_max_size = DTB_MAX;
} else {
search_space = dtb_max_size = atoi(argv[3]);
}
if (stat(argv[2], &s)) {
fprintf(stderr, "DTB not found\n");
goto err1;
}
len = s.st_size;
if (len + 8 > dtb_max_size) {
fprintf(stderr, "DTB too big\n");
goto err1;
}
if (((fddtb = open(argv[2], O_RDONLY)) < 0) ||
(ptrdtb = (char *) mmap(0, dtb_max_size, PROT_READ, MAP_SHARED, fddtb, 0)) == (void *) (-1)) {
fprintf(stderr, "Could not open DTB");
goto err2;
}
if (((fd = open(argv[1], O_RDWR)) < 0) ||
(ptr = (char *) mmap(0, search_space + dtb_max_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == (void *) (-1)) {
fprintf(stderr, "Could not open kernel image");
goto err3;
}
for (p = ptr; p < (ptr + search_space); p += 4) {
if (memcmp(p, "OWRTDTB:", 8) == 0) {
found = 1;
p += 8;
break;
}
}
if (!found) {
fprintf(stderr, "DTB marker not found!\n");
goto err4;
}
memset(p, 0, dtb_max_size - 8);
memcpy(p, ptrdtb, len);
msync(p, len, MS_SYNC|MS_INVALIDATE);
ret = 0;
err4:
munmap((void *) ptr, len);
err3:
if (fd > 0)
close(fd);
munmap((void *) ptrdtb, len);
err2:
if (fddtb > 0)
close(fddtb);
err1:
return ret;
}