1/*
  2 * Copyright © 2007 Eugene Konev <ejka@openwrt.org>
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License as published by
  6 * the Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 *
  9 * This program is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12 * GNU General Public License for more details.
 13 *
 14 * You should have received a copy of the GNU General Public License
 15 * along with this program; if not, write to the Free Software
 16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 17 *
 18 * TI AR7 flash partition table.
 19 * Based on ar7 map by Felix Fietkau <nbd@openwrt.org>
 20 *
 21 */
 22
 23#include <linux/kernel.h>
 24#include <linux/slab.h>
 25
 26#include <linux/mtd/mtd.h>
 27#include <linux/mtd/partitions.h>
 28#include <linux/bootmem.h>
 29#include <linux/module.h>
 30
 31#include <uapi/linux/magic.h>
 32
 33#define AR7_PARTS	4
 34#define ROOT_OFFSET	0xe0000
 35
 36#define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
 37#define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
 38
 39struct ar7_bin_rec {
 40	unsigned int checksum;
 41	unsigned int length;
 42	unsigned int address;
 43};
 44
 45static int create_mtd_partitions(struct mtd_info *master,
 46				 const struct mtd_partition **pparts,
 47				 struct mtd_part_parser_data *data)
 48{
 49	struct ar7_bin_rec header;
 50	unsigned int offset;
 51	size_t len;
 52	unsigned int pre_size = master->erasesize, post_size = 0;
 53	unsigned int root_offset = ROOT_OFFSET;
 54
 55	int retries = 10;
 56	struct mtd_partition *ar7_parts;
 57
 58	ar7_parts = kzalloc(sizeof(*ar7_parts) * AR7_PARTS, GFP_KERNEL);
 59	if (!ar7_parts)
 60		return -ENOMEM;
 61	ar7_parts[0].name = "loader";
 62	ar7_parts[0].offset = 0;
 63	ar7_parts[0].size = master->erasesize;
 64	ar7_parts[0].mask_flags = MTD_WRITEABLE;
 65
 66	ar7_parts[1].name = "config";
 67	ar7_parts[1].offset = 0;
 68	ar7_parts[1].size = master->erasesize;
 69	ar7_parts[1].mask_flags = 0;
 70
 71	do { /* Try 10 blocks starting from master->erasesize */
 72		offset = pre_size;
 73		mtd_read(master, offset, sizeof(header), &len,
 74			 (uint8_t *)&header);
 75		if (!strncmp((char *)&header, "TIENV0.8", 8))
 76			ar7_parts[1].offset = pre_size;
 77		if (header.checksum == LOADER_MAGIC1)
 78			break;
 79		if (header.checksum == LOADER_MAGIC2)
 80			break;
 81		pre_size += master->erasesize;
 82	} while (retries--);
 83
 84	pre_size = offset;
 85
 86	if (!ar7_parts[1].offset) {
 87		ar7_parts[1].offset = master->size - master->erasesize;
 88		post_size = master->erasesize;
 89	}
 90
 91	switch (header.checksum) {
 92	case LOADER_MAGIC1:
 93		while (header.length) {
 94			offset += sizeof(header) + header.length;
 95			mtd_read(master, offset, sizeof(header), &len,
 96				 (uint8_t *)&header);
 97		}
 98		root_offset = offset + sizeof(header) + 4;
 99		break;
100	case LOADER_MAGIC2:
101		while (header.length) {
102			offset += sizeof(header) + header.length;
103			mtd_read(master, offset, sizeof(header), &len,
104				 (uint8_t *)&header);
105		}
106		root_offset = offset + sizeof(header) + 4 + 0xff;
107		root_offset &= ~(uint32_t)0xff;
108		break;
109	default:
110		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
111		break;
112	}
113
114	mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
115	if (header.checksum != SQUASHFS_MAGIC) {
116		root_offset += master->erasesize - 1;
117		root_offset &= ~(master->erasesize - 1);
118	}
119
120	ar7_parts[2].name = "linux";
121	ar7_parts[2].offset = pre_size;
122	ar7_parts[2].size = master->size - pre_size - post_size;
123	ar7_parts[2].mask_flags = 0;
124
125	ar7_parts[3].name = "rootfs";
126	ar7_parts[3].offset = root_offset;
127	ar7_parts[3].size = master->size - root_offset - post_size;
128	ar7_parts[3].mask_flags = 0;
129
130	*pparts = ar7_parts;
131	return AR7_PARTS;
132}
133
134static struct mtd_part_parser ar7_parser = {
135	.parse_fn = create_mtd_partitions,
136	.name = "ar7part",
137};
138module_mtd_part_parser(ar7_parser);
139
140MODULE_LICENSE("GPL");
141MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
142		"Eugene Konev <ejka@openwrt.org>");
143MODULE_DESCRIPTION("MTD partitioning for TI AR7");