openwrtv4/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_wrgg.c
George Hopkins 5c7a58764e kernel: mtdsplit: split by WRG header
Support splitting WRG images, which can be found in older
D-Link devices.

Signed-off-by: George Hopkins <george-hopkins@null.net>
2018-02-13 11:16:49 +01:00

124 lines
2.9 KiB
C

/*
* Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
* Copyright (C) 2016 Stijn Tintel <stijn@linux-ipv6.be>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/byteorder/generic.h>
#include "mtdsplit.h"
#define WRGG_NR_PARTS 2
#define WRGG_MIN_ROOTFS_OFFS 0x80000 /* 512KiB */
#define WRGG03_MAGIC 0x20080321
#define WRG_MAGIC 0x20040220
struct wrgg03_header {
char signature[32];
uint32_t magic1;
uint32_t magic2;
char version[16];
char model[16];
uint32_t flag[2];
uint32_t reserve[2];
char buildno[16];
uint32_t size;
uint32_t offset;
char devname[32];
char digest[16];
} __attribute__ ((packed));
struct wrg_header {
char signature[32];
uint32_t magic1;
uint32_t magic2;
uint32_t size;
uint32_t offset;
char devname[32];
char digest[16];
} __attribute__ ((packed));
static int mtdsplit_parse_wrgg(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct wrgg03_header hdr;
size_t hdr_len, retlen, kernel_ent_size;
size_t rootfs_offset;
struct mtd_partition *parts;
enum mtdsplit_part_type type;
int err;
hdr_len = sizeof(hdr);
err = mtd_read(master, 0, hdr_len, &retlen, (void *) &hdr);
if (err)
return err;
if (retlen != hdr_len)
return -EIO;
/* sanity checks */
if (le32_to_cpu(hdr.magic1) == WRGG03_MAGIC) {
kernel_ent_size = hdr_len + be32_to_cpu(hdr.size);
} else if (le32_to_cpu(hdr.magic1) == WRG_MAGIC) {
kernel_ent_size = sizeof(struct wrg_header) + le32_to_cpu(
((struct wrg_header*)&hdr)->size);
} else {
return -EINVAL;
}
if (kernel_ent_size > master->size)
return -EINVAL;
/*
* The size in the header covers the rootfs as well.
* Start the search from an arbitrary offset.
*/
err = mtd_find_rootfs_from(master, WRGG_MIN_ROOTFS_OFFS,
master->size, &rootfs_offset, &type);
if (err)
return err;
parts = kzalloc(WRGG_NR_PARTS * sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;
parts[0].name = KERNEL_PART_NAME;
parts[0].offset = 0;
parts[0].size = rootfs_offset;
parts[1].name = ROOTFS_PART_NAME;
parts[1].offset = rootfs_offset;
parts[1].size = master->size - rootfs_offset;
*pparts = parts;
return WRGG_NR_PARTS;
}
static struct mtd_part_parser mtdsplit_wrgg_parser = {
.owner = THIS_MODULE,
.name = "wrgg-fw",
.parse_fn = mtdsplit_parse_wrgg,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
static int __init mtdsplit_wrgg_init(void)
{
register_mtd_parser(&mtdsplit_wrgg_parser);
return 0;
}
subsys_initcall(mtdsplit_wrgg_init);