OpenWrt – Rev 3
?pathlinks?
/*
* Copyright (c) 2015 The Linux Foundation
* Copyright (C) 2014 Gabor Juhos <juhosg@openwrt.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/types.h>
#include <linux/byteorder/generic.h>
#include <linux/slab.h>
#include <linux/of_fdt.h>
#include "mtdsplit.h"
struct fdt_header {
uint32_t magic; /* magic word FDT_MAGIC */
uint32_t totalsize; /* total size of DT block */
uint32_t off_dt_struct; /* offset to structure */
uint32_t off_dt_strings; /* offset to strings */
uint32_t off_mem_rsvmap; /* offset to memory reserve map */
uint32_t version; /* format version */
uint32_t last_comp_version; /* last compatible version */
/* version 2 fields below */
uint32_t boot_cpuid_phys; /* Which physical CPU id we're
booting on */
/* version 3 fields below */
uint32_t size_dt_strings; /* size of the strings block */
/* version 17 fields below */
uint32_t size_dt_struct; /* size of the structure block */
};
static int
mtdsplit_fit_parse(struct mtd_info *mtd,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct fdt_header hdr;
size_t hdr_len, retlen;
size_t offset;
size_t fit_offset, fit_size;
size_t rootfs_offset, rootfs_size;
struct mtd_partition *parts;
int ret;
hdr_len = sizeof(struct fdt_header);
/* Parse the MTD device & search for the FIT image location */
for(offset = 0; offset < mtd->size; offset += mtd->erasesize) {
ret = mtd_read(mtd, 0, hdr_len, &retlen, (void*) &hdr);
if (ret) {
pr_err("read error in \"%s\" at offset 0x%llx\n",
mtd->name, (unsigned long long) offset);
return ret;
}
if (retlen != hdr_len) {
pr_err("short read in \"%s\"\n", mtd->name);
return -EIO;
}
/* Check the magic - see if this is a FIT image */
if (be32_to_cpu(hdr.magic) != OF_DT_HEADER) {
pr_debug("no valid FIT image found in \"%s\" at offset %llx\n",
mtd->name, (unsigned long long) offset);
continue;
}
/* We found a FIT image. Let's keep going */
break;
}
fit_offset = offset;
fit_size = be32_to_cpu(hdr.totalsize);
if (fit_size == 0) {
pr_err("FIT image in \"%s\" at offset %llx has null size\n",
mtd->name, (unsigned long long) fit_offset);
return -ENODEV;
}
/* Search for the rootfs partition after the FIT image */
ret = mtd_find_rootfs_from(mtd, fit_offset + fit_size, mtd->size,
&rootfs_offset, NULL);
if (ret) {
pr_info("no rootfs found after FIT image in \"%s\"\n",
mtd->name);
return ret;
}
rootfs_size = mtd->size - rootfs_offset;
parts = kzalloc(2 * sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;
parts[0].name = KERNEL_PART_NAME;
parts[0].offset = fit_offset;
parts[0].size = mtd_rounddown_to_eb(fit_size, mtd) + mtd->erasesize;
parts[1].name = ROOTFS_PART_NAME;
parts[1].offset = rootfs_offset;
parts[1].size = rootfs_size;
*pparts = parts;
return 2;
}
static struct mtd_part_parser uimage_parser = {
.owner = THIS_MODULE,
.name = "fit-fw",
.parse_fn = mtdsplit_fit_parse,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
/**************************************************
* Init
**************************************************/
static int __init mtdsplit_fit_init(void)
{
register_mtd_parser(&uimage_parser);
return 0;
}
module_init(mtdsplit_fit_init);