OpenWrt – Rev 1
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/*
* Copyright (C) 2013 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.
*
*/
#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/vmalloc.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/version.h>
#include <linux/byteorder/generic.h>
#include "mtdsplit.h"
/*
* uimage_header itself is only 64B, but it may be prepended with another data.
* Currently the biggest size is for Edimax devices: 20B + 64B
*/
#define MAX_HEADER_LEN 84
#define IH_MAGIC 0x27051956 /* Image Magic Number */
#define IH_NMLEN 32 /* Image Name Length */
#define IH_OS_LINUX 5 /* Linux */
#define IH_TYPE_KERNEL 2 /* OS Kernel Image */
#define IH_TYPE_FILESYSTEM 7 /* Filesystem Image */
/*
* Legacy format image header,
* all data in network byte order (aka natural aka bigendian).
*/
struct uimage_header {
uint32_t ih_magic; /* Image Header Magic Number */
uint32_t ih_hcrc; /* Image Header CRC Checksum */
uint32_t ih_time; /* Image Creation Timestamp */
uint32_t ih_size; /* Image Data Size */
uint32_t ih_load; /* Data Load Address */
uint32_t ih_ep; /* Entry Point Address */
uint32_t ih_dcrc; /* Image Data CRC Checksum */
uint8_t ih_os; /* Operating System */
uint8_t ih_arch; /* CPU architecture */
uint8_t ih_type; /* Image Type */
uint8_t ih_comp; /* Compression Type */
uint8_t ih_name[IH_NMLEN]; /* Image Name */
};
static int
read_uimage_header(struct mtd_info *mtd, size_t offset, u_char *buf,
size_t header_len)
{
size_t retlen;
int ret;
ret = mtd_read(mtd, offset, header_len, &retlen, buf);
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;
}
/**
* __mtdsplit_parse_uimage - scan partition and create kernel + rootfs parts
*
* @find_header: function to call for a block of data that will return offset
* of a valid uImage header if found
*/
static int __mtdsplit_parse_uimage(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data,
ssize_t (*find_header)(u_char *buf, size_t len))
{
struct mtd_partition *parts;
u_char *buf;
int nr_parts;
size_t offset;
size_t uimage_offset;
size_t uimage_size = 0;
size_t rootfs_offset;
size_t rootfs_size = 0;
int uimage_part, rf_part;
int ret;
enum mtdsplit_part_type type;
nr_parts = 2;
parts = kzalloc(nr_parts * sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;
buf = vmalloc(MAX_HEADER_LEN);
if (!buf) {
ret = -ENOMEM;
goto err_free_parts;
}
/* find uImage on erase block boundaries */
for (offset = 0; offset < master->size; offset += master->erasesize) {
struct uimage_header *header;
uimage_size = 0;
ret = read_uimage_header(master, offset, buf, MAX_HEADER_LEN);
if (ret)
continue;
ret = find_header(buf, MAX_HEADER_LEN);
if (ret < 0) {
pr_debug("no valid uImage found in \"%s\" at offset %llx\n",
master->name, (unsigned long long) offset);
continue;
}
header = (struct uimage_header *)(buf + ret);
uimage_size = sizeof(*header) + be32_to_cpu(header->ih_size) + ret;
if ((offset + uimage_size) > master->size) {
pr_debug("uImage exceeds MTD device \"%s\"\n",
master->name);
continue;
}
break;
}
if (uimage_size == 0) {
pr_debug("no uImage found in \"%s\"\n", master->name);
ret = -ENODEV;
goto err_free_buf;
}
uimage_offset = offset;
if (uimage_offset == 0) {
uimage_part = 0;
rf_part = 1;
/* find the roots after the uImage */
ret = mtd_find_rootfs_from(master, uimage_offset + uimage_size,
master->size, &rootfs_offset, &type);
if (ret) {
pr_debug("no rootfs after uImage in \"%s\"\n",
master->name);
goto err_free_buf;
}
rootfs_size = master->size - rootfs_offset;
uimage_size = rootfs_offset - uimage_offset;
} else {
rf_part = 0;
uimage_part = 1;
/* check rootfs presence at offset 0 */
ret = mtd_check_rootfs_magic(master, 0, &type);
if (ret) {
pr_debug("no rootfs before uImage in \"%s\"\n",
master->name);
goto err_free_buf;
}
rootfs_offset = 0;
rootfs_size = uimage_offset;
}
if (rootfs_size == 0) {
pr_debug("no rootfs found in \"%s\"\n", master->name);
ret = -ENODEV;
goto err_free_buf;
}
parts[uimage_part].name = KERNEL_PART_NAME;
parts[uimage_part].offset = uimage_offset;
parts[uimage_part].size = uimage_size;
if (type == MTDSPLIT_PART_TYPE_UBI)
parts[rf_part].name = UBI_PART_NAME;
else
parts[rf_part].name = ROOTFS_PART_NAME;
parts[rf_part].offset = rootfs_offset;
parts[rf_part].size = rootfs_size;
vfree(buf);
*pparts = parts;
return nr_parts;
err_free_buf:
vfree(buf);
err_free_parts:
kfree(parts);
return ret;
}
static ssize_t uimage_verify_default(u_char *buf, size_t len)
{
struct uimage_header *header = (struct uimage_header *)buf;
/* default sanity checks */
if (be32_to_cpu(header->ih_magic) != IH_MAGIC) {
pr_debug("invalid uImage magic: %08x\n",
be32_to_cpu(header->ih_magic));
return -EINVAL;
}
if (header->ih_os != IH_OS_LINUX) {
pr_debug("invalid uImage OS: %08x\n",
be32_to_cpu(header->ih_os));
return -EINVAL;
}
if (header->ih_type != IH_TYPE_KERNEL) {
pr_debug("invalid uImage type: %08x\n",
be32_to_cpu(header->ih_type));
return -EINVAL;
}
return 0;
}
static int
mtdsplit_uimage_parse_generic(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
return __mtdsplit_parse_uimage(master, pparts, data,
uimage_verify_default);
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
static const struct of_device_id mtdsplit_uimage_of_match_table[] = {
{ .compatible = "denx,uimage" },
{},
};
#endif
static struct mtd_part_parser uimage_generic_parser = {
.owner = THIS_MODULE,
.name = "uimage-fw",
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
.of_match_table = mtdsplit_uimage_of_match_table,
#endif
.parse_fn = mtdsplit_uimage_parse_generic,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
#define FW_MAGIC_WNR2000V1 0x32303031
#define FW_MAGIC_WNR2000V3 0x32303033
#define FW_MAGIC_WNR2000V4 0x32303034
#define FW_MAGIC_WNR2200 0x32323030
#define FW_MAGIC_WNR612V2 0x32303631
#define FW_MAGIC_WNR1000V2 0x31303031
#define FW_MAGIC_WNR1000V2_VC 0x31303030
#define FW_MAGIC_WNDR3700 0x33373030
#define FW_MAGIC_WNDR3700V2 0x33373031
#define FW_MAGIC_WPN824N 0x31313030
static ssize_t uimage_verify_wndr3700(u_char *buf, size_t len)
{
struct uimage_header *header = (struct uimage_header *)buf;
uint8_t expected_type = IH_TYPE_FILESYSTEM;
switch (be32_to_cpu(header->ih_magic)) {
case FW_MAGIC_WNR612V2:
case FW_MAGIC_WNR1000V2:
case FW_MAGIC_WNR1000V2_VC:
case FW_MAGIC_WNR2000V1:
case FW_MAGIC_WNR2000V3:
case FW_MAGIC_WNR2200:
case FW_MAGIC_WNDR3700:
case FW_MAGIC_WNDR3700V2:
case FW_MAGIC_WPN824N:
break;
case FW_MAGIC_WNR2000V4:
expected_type = IH_TYPE_KERNEL;
break;
default:
return -EINVAL;
}
if (header->ih_os != IH_OS_LINUX ||
header->ih_type != expected_type)
return -EINVAL;
return 0;
}
static int
mtdsplit_uimage_parse_netgear(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
return __mtdsplit_parse_uimage(master, pparts, data,
uimage_verify_wndr3700);
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
static const struct of_device_id mtdsplit_uimage_netgear_of_match_table[] = {
{ .compatible = "netgear,uimage" },
{},
};
#endif
static struct mtd_part_parser uimage_netgear_parser = {
.owner = THIS_MODULE,
.name = "netgear-fw",
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
.of_match_table = mtdsplit_uimage_netgear_of_match_table,
#endif
.parse_fn = mtdsplit_uimage_parse_netgear,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
/**************************************************
* Edimax
**************************************************/
#define FW_EDIMAX_OFFSET 20
#define FW_MAGIC_EDIMAX 0x43535953
static ssize_t uimage_find_edimax(u_char *buf, size_t len)
{
u32 *magic;
if (len < FW_EDIMAX_OFFSET + sizeof(struct uimage_header)) {
pr_err("Buffer too small for checking Edimax header\n");
return -ENOSPC;
}
magic = (u32 *)buf;
if (be32_to_cpu(*magic) != FW_MAGIC_EDIMAX)
return -EINVAL;
if (!uimage_verify_default(buf + FW_EDIMAX_OFFSET, len))
return FW_EDIMAX_OFFSET;
return -EINVAL;
}
static int
mtdsplit_uimage_parse_edimax(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
return __mtdsplit_parse_uimage(master, pparts, data,
uimage_find_edimax);
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
static const struct of_device_id mtdsplit_uimage_edimax_of_match_table[] = {
{ .compatible = "edimax,uimage" },
{},
};
#endif
static struct mtd_part_parser uimage_edimax_parser = {
.owner = THIS_MODULE,
.name = "edimax-fw",
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
.of_match_table = mtdsplit_uimage_edimax_of_match_table,
#endif
.parse_fn = mtdsplit_uimage_parse_edimax,
.type = MTD_PARSER_TYPE_FIRMWARE,
};
/**************************************************
* Init
**************************************************/
static int __init mtdsplit_uimage_init(void)
{
register_mtd_parser(&uimage_generic_parser);
register_mtd_parser(&uimage_netgear_parser);
register_mtd_parser(&uimage_edimax_parser);
return 0;
}
module_init(mtdsplit_uimage_init);