openwrt/target/linux/generic/files/drivers/mtd/mtdsplit_lzma.c

97 lines
2.0 KiB
C

/*
* Copyright (C) 2014 Gabor Juhos <juhosg@openwrt.org>
*
* 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 <asm/unaligned.h>
#include "mtdsplit.h"
#define LZMA_NR_PARTS 2
#define LZMA_PROPERTIES_SIZE 5
struct lzma_header {
u8 props[LZMA_PROPERTIES_SIZE];
u8 size_low[4];
u8 size_high[4];
};
static int mtdsplit_parse_lzma(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct lzma_header hdr;
size_t hdr_len, retlen;
size_t rootfs_offset;
u32 t;
struct mtd_partition *parts;
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;
/* verify LZMA properties */
if (hdr.props[0] >= (9 * 5 * 5))
return -EINVAL;
t = get_unaligned_le32(&hdr.props[1]);
if (!is_power_of_2(t))
return -EINVAL;
t = get_unaligned_le32(&hdr.size_high);
if (t)
return -EINVAL;
err = mtd_find_rootfs_from(master, master->erasesize,
master->size, &rootfs_offset);
if (err)
return err;
parts = kzalloc(LZMA_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 LZMA_NR_PARTS;
}
static struct mtd_part_parser mtdsplit_lzma_parser = {
.owner = THIS_MODULE,
.name = "lzma-fw",
.parse_fn = mtdsplit_parse_lzma,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
static int __init mtdsplit_lzma_init(void)
{
register_mtd_parser(&mtdsplit_lzma_parser);
return 0;
}
subsys_initcall(mtdsplit_lzma_init);