linux/drivers/mtd/ar7part.c

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/*
* Copyright © 2007 Eugene Konev <ejka@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* TI AR7 flash partition table.
* Based on ar7 map by Felix Fietkau <nbd@openwrt.org>
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <uapi/linux/magic.h>
#define AR7_PARTS 4
#define ROOT_OFFSET 0xe0000
#define LOADER_MAGIC1 le32_to_cpu(0xfeedfa42)
#define LOADER_MAGIC2 le32_to_cpu(0xfeed1281)
struct ar7_bin_rec {
unsigned int checksum;
unsigned int length;
unsigned int address;
};
static int create_mtd_partitions(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct ar7_bin_rec header;
unsigned int offset;
size_t len;
unsigned int pre_size = master->erasesize, post_size = 0;
unsigned int root_offset = ROOT_OFFSET;
int retries = 10;
struct mtd_partition *ar7_parts;
ar7_parts = kzalloc(sizeof(*ar7_parts) * AR7_PARTS, GFP_KERNEL);
if (!ar7_parts)
return -ENOMEM;
ar7_parts[0].name = "loader";
ar7_parts[0].offset = 0;
ar7_parts[0].size = master->erasesize;
ar7_parts[0].mask_flags = MTD_WRITEABLE;
ar7_parts[1].name = "config";
ar7_parts[1].offset = 0;
ar7_parts[1].size = master->erasesize;
ar7_parts[1].mask_flags = 0;
do { /* Try 10 blocks starting from master->erasesize */
offset = pre_size;
mtd_read(master, offset, sizeof(header), &len,
(uint8_t *)&header);
if (!strncmp((char *)&header, "TIENV0.8", 8))
ar7_parts[1].offset = pre_size;
if (header.checksum == LOADER_MAGIC1)
break;
if (header.checksum == LOADER_MAGIC2)
break;
pre_size += master->erasesize;
} while (retries--);
pre_size = offset;
if (!ar7_parts[1].offset) {
ar7_parts[1].offset = master->size - master->erasesize;
post_size = master->erasesize;
}
switch (header.checksum) {
case LOADER_MAGIC1:
while (header.length) {
offset += sizeof(header) + header.length;
mtd_read(master, offset, sizeof(header), &len,
(uint8_t *)&header);
}
root_offset = offset + sizeof(header) + 4;
break;
case LOADER_MAGIC2:
while (header.length) {
offset += sizeof(header) + header.length;
mtd_read(master, offset, sizeof(header), &len,
(uint8_t *)&header);
}
root_offset = offset + sizeof(header) + 4 + 0xff;
root_offset &= ~(uint32_t)0xff;
break;
default:
printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
break;
}
mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
if (header.checksum != SQUASHFS_MAGIC) {
root_offset += master->erasesize - 1;
root_offset &= ~(master->erasesize - 1);
}
ar7_parts[2].name = "linux";
ar7_parts[2].offset = pre_size;
ar7_parts[2].size = master->size - pre_size - post_size;
ar7_parts[2].mask_flags = 0;
ar7_parts[3].name = "rootfs";
ar7_parts[3].offset = root_offset;
ar7_parts[3].size = master->size - root_offset - post_size;
ar7_parts[3].mask_flags = 0;
*pparts = ar7_parts;
return AR7_PARTS;
}
static struct mtd_part_parser ar7_parser = {
.owner = THIS_MODULE,
.parse_fn = create_mtd_partitions,
.name = "ar7part",
};
static int __init ar7_parser_init(void)
{
register_mtd_parser(&ar7_parser);
return 0;
}
static void __exit ar7_parser_exit(void)
{
deregister_mtd_parser(&ar7_parser);
}
module_init(ar7_parser_init);
module_exit(ar7_parser_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR( "Felix Fietkau <nbd@openwrt.org>, "
"Eugene Konev <ejka@openwrt.org>");
MODULE_DESCRIPTION("MTD partitioning for TI AR7");