alistair23-linux/drivers/mtd/ar7part.c
Brian Norris b9adf469f8 mtd: partitions: make parsers return 'const' partition arrays
We only want to modify these arrays inside the parser "drivers", so the
drivers should construct them however they like, then return them as
immutable arrays.

This will make other refactorings easier.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2015-12-09 10:21:57 -08:00

144 lines
3.9 KiB
C

/*
* 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,
const 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 = {
.parse_fn = create_mtd_partitions,
.name = "ar7part",
};
module_mtd_part_parser(ar7_parser);
MODULE_LICENSE("GPL");
MODULE_AUTHOR( "Felix Fietkau <nbd@openwrt.org>, "
"Eugene Konev <ejka@openwrt.org>");
MODULE_DESCRIPTION("MTD partitioning for TI AR7");