openwrt/package/system/mtd/src/tpl_ramips_recoveryflag.c
David Bauer 1e06482f7d mtd: add logic for TP-Link ramips recovery magic
This adds an option to set the recovery flag of newer TP-Link MediaTek
boards and remove it after a successful write.

To make use of this feature, add the '-t' option to mtd-write.

The '-t' option takes the mtd partition containing the recovery flag
(usually 'romfile') as an argument. Make sure this partition is not
flagged as read-only!

Example:
 > mtd -t romfile write owrt.bin firmware

This command writes the recovery-flag before it begins writing the image
to the firmware partition. After the image-write has been successful,
the recovery flag is removed.

This way, the TP-Link web-recovery is automatically enabled on an
unsucessful flash (e.g. power loss).

This option is only available if the mtd package is compiled for the
ramips target.

Signed-off-by: David Bauer <mail@david-bauer.net>
2019-01-26 21:46:32 +01:00

95 lines
2.0 KiB
C

/*
* TP-Link recovery flag set and unset code for ramips target
*
* Copyright (C) 2018 David Bauer <mail@david-bauer.net>
*
* 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdint.h>
#include <mtd/mtd-user.h>
#include <sys/ioctl.h>
#include "mtd.h"
#define TPL_RECOVER_MAGIC 0x89abcdef
#define TPL_NO_RECOVER_MAGIC 0x00000000
struct uboot_args {
uint32_t magic;
};
int mtd_tpl_recoverflag_write(const char *mtd, const bool recovery_active)
{
struct erase_info_user erase_info;
struct uboot_args *args;
uint32_t magic;
int ret = 0;
int fd;
args = malloc(erasesize);
if (!args) {
fprintf(stderr, "Could not allocate memory!\n");
return -1;
}
fd = mtd_check_open(mtd);
if (fd < 0) {
fprintf(stderr, "Could not open mtd device: %s\n", mtd);
ret = -1;
goto out;
}
/* read first block (containing the magic) */
pread(fd, args, erasesize, 0);
/* set magic to desired value */
magic = TPL_RECOVER_MAGIC;
if (!recovery_active)
magic = TPL_NO_RECOVER_MAGIC;
/* no need to write when magic is already set correctly */
if (magic == args->magic)
goto out;
/* erase first block (containing the magic) */
erase_info.start = 0;
erase_info.length = erasesize;
ret = ioctl(fd, MEMERASE, &erase_info);
if (ret < 0) {
fprintf(stderr, "failed to erase block: %i\n", ret);
goto out;
}
/* write magic to flash */
args->magic = magic;
ret = pwrite(fd, args, erasesize, 0);
if (ret < 0)
fprintf(stderr, "failed to write: %i\n", ret);
sync();
out:
free(args);
close(fd);
return ret;
}