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/*
* Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2014 Felix Fietkau <nbd@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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 TRX_MAGIC 0x30524448 /* "HDR0" */
struct trx_header {
__le32 magic;
__le32 len;
__le32 crc32;
__le32 flag_version;
__le32 offset[4];
};
static int
read_trx_header(struct mtd_info *mtd, size_t offset,
struct trx_header *header)
{
size_t header_len;
size_t retlen;
int ret;
header_len = sizeof(*header);
ret = mtd_read(mtd, offset, header_len, &retlen,
(unsigned char *) header);
if (ret) {
pr_debug("read error in \"%s\"\n", mtd->name);
return ret;
}
if (retlen != header_len) {
pr_debug("short read in \"%s\"\n", mtd->name);
return -EIO;
}
return 0;
}
static int
mtdsplit_parse_trx(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct mtd_partition *parts;
struct trx_header hdr;
int nr_parts;
size_t offset;
size_t trx_offset;
size_t trx_size = 0;
size_t rootfs_offset;
size_t rootfs_size = 0;
int ret;
nr_parts = 2;
parts = kzalloc(nr_parts * sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;
/* find trx image on erase block boundaries */
for (offset = 0; offset < master->size; offset += master->erasesize) {
trx_size = 0;
ret = read_trx_header(master, offset, &hdr);
if (ret)
continue;
if (hdr.magic != cpu_to_le32(TRX_MAGIC)) {
pr_debug("no valid trx header found in \"%s\" at offset %llx\n",
master->name, (unsigned long long) offset);
continue;
}
trx_size = le32_to_cpu(hdr.len);
if ((offset + trx_size) > master->size) {
pr_debug("trx image exceeds MTD device \"%s\"\n",
master->name);
continue;
}
break;
}
if (trx_size == 0) {
pr_debug("no trx header found in \"%s\"\n", master->name);
ret = -ENODEV;
goto err;
}
trx_offset = offset + hdr.offset[0];
rootfs_offset = offset + hdr.offset[1];
rootfs_size = master->size - rootfs_offset;
trx_size = rootfs_offset - trx_offset;
if (rootfs_size == 0) {
pr_debug("no rootfs found in \"%s\"\n", master->name);
ret = -ENODEV;
goto err;
}
parts[0].name = KERNEL_PART_NAME;
parts[0].offset = trx_offset;
parts[0].size = trx_size;
parts[1].name = ROOTFS_PART_NAME;
parts[1].offset = rootfs_offset;
parts[1].size = rootfs_size;
*pparts = parts;
return nr_parts;
err:
kfree(parts);
return ret;
}
static struct mtd_part_parser trx_parser = {
.owner = THIS_MODULE,
.name = "trx-fw",
.parse_fn = mtdsplit_parse_trx,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
static int __init mtdsplit_trx_init(void)
{
register_mtd_parser(&trx_parser);
return 0;
}
module_init(mtdsplit_trx_init);
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