You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
openwrt/package/system/mtd/src/linksys_bootcount_fix.c

116 lines
2.4 KiB
C

/*
* Linksys boot counter reset code for mtd
*
* Copyright (C) 2013 Jonas Gorski <jogo@openwrt.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License v2
* as published by the Free Software Foundation.
*
* 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.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <endian.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <mtd/mtd-user.h>
#include "mtd.h"
#define BOOTCOUNT_MAGIC 0x20110811
struct bootcounter {
uint32_t magic;
uint32_t count;
uint32_t checksum;
};
static char page[2048];
int mtd_resetbc(const char *mtd)
{
struct mtd_info_user mtd_info;
struct bootcounter *curr = (struct bootcounter *)page;
unsigned int i;
int last_count = 0;
int num_bc;
int fd;
int ret;
fd = mtd_check_open(mtd);
if (ioctl(fd, MEMGETINFO, &mtd_info) < 0) {
fprintf(stderr, "failed to get mtd info!\n");
return -1;
}
num_bc = mtd_info.size / 16;
for (i = 0; i < num_bc; i++) {
pread(fd, curr, sizeof(*curr), i * 16);
if (curr->magic != (BOOTCOUNT_MAGIC) && curr->magic != 0xffffffff) {
fprintf(stderr, "unexpected magic %08x, bailing out\n", curr->magic);
goto out;
}
if (curr->magic == 0xffffffff)
break;
last_count = curr->count;
}
/* no need to do writes when last boot count is already 0 */
if (last_count == 0)
goto out;
if (i == num_bc) {
struct erase_info_user erase_info;
erase_info.start = 0;
erase_info.length = mtd_info.size;
/* erase block */
ret = ioctl(fd, MEMERASE, &erase_info);
if (ret < 0) {
fprintf(stderr, "failed to erase block: %i\n", ret);
return -1;
}
i = 0;
}
memset(curr, 0xff, 16);
curr->magic = BOOTCOUNT_MAGIC;
curr->count = 0;
curr->checksum = BOOTCOUNT_MAGIC;
ret = pwrite(fd, curr, 16, i * 16);
if (ret < 0)
fprintf(stderr, "failed to write: %i\n", ret);
sync();
out:
close(fd);
return 0;
}