target/linux/ar7/files/drivers/mtd/ar7part.c

   1 /*
   2  * Copyright (C) 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/magic.h>
  30
  31 #define AR7_PARTS       4
  32 #define ROOT_OFFSET     0xe0000
  33
  34 #define LOADER_MAGIC1   le32_to_cpu(0xfeedfa42)
  35 #define LOADER_MAGIC2   le32_to_cpu(0xfeed1281)
  36
  37 struct ar7_bin_rec {
  38         unsigned int checksum;
  39         unsigned int length;
  40         unsigned int address;
  41 };
  42
  43 static struct mtd_partition ar7_parts[AR7_PARTS];
  44
  45 static int create_mtd_partitions(struct mtd_info *master,
  46                                  struct mtd_partition **pparts,
  47                                  unsigned long origin)
  48 {
  49         struct ar7_bin_rec header;
  50         unsigned int offset, len;
  51         unsigned int pre_size = master->erasesize, post_size = 0;
  52         unsigned int root_offset = ROOT_OFFSET;
  53
  54         int retries = 10;
  55
  56         ar7_parts[0].name = "loader";
  57         ar7_parts[0].offset = 0;
  58         ar7_parts[0].size = master->erasesize;
  59         ar7_parts[0].mask_flags = MTD_WRITEABLE;
  60
  61         ar7_parts[1].name = "config";
  62         ar7_parts[1].offset = 0;
  63         ar7_parts[1].size = master->erasesize;
  64         ar7_parts[1].mask_flags = 0;
  65
  66         do { /* Try 10 blocks starting from master->erasesize */
  67                 offset = pre_size;
  68                 master->read(master, offset,
  69                         sizeof(header), &len, (u8 *)&header);
  70                 if (!strncmp((char *)&header, "TIENV0.8", 8))
  71                         ar7_parts[1].offset = pre_size;
  72                 if (header.checksum == LOADER_MAGIC1)
  73                         break;
  74                 if (header.checksum == LOADER_MAGIC2)
  75                         break;
  76                 pre_size += master->erasesize;
  77         } while (retries--);
  78
  79         pre_size = offset;
  80
  81         if (!ar7_parts[1].offset) {
  82                 ar7_parts[1].offset = master->size - master->erasesize;
  83                 post_size = master->erasesize;
  84         }
  85
  86         switch (header.checksum) {
  87         case LOADER_MAGIC1:
  88                 while (header.length) {
  89                         offset += sizeof(header) + header.length;
  90                         master->read(master, offset, sizeof(header),
  91                                      &len, (u8 *)&header);
  92                 }
  93                 root_offset = offset + sizeof(header) + 4;
  94                 break;
  95         case LOADER_MAGIC2:
  96                 while (header.length) {
  97                         offset += sizeof(header) + header.length;
  98                         master->read(master, offset, sizeof(header),
  99                                      &len, (u8 *)&header);
 100                 }
 101                 root_offset = offset + sizeof(header) + 4 + 0xff;
 102                 root_offset &= ~(u32)0xff;
 103                 break;
 104         default:
 105                 printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
 106                 break;
 107         }
 108
 109         master->read(master, root_offset,
 110                 sizeof(header), &len, (u8 *)&header);
 111         if (header.checksum != SQUASHFS_MAGIC) {
 112                 root_offset += master->erasesize - 1;
 113                 root_offset &= ~(master->erasesize - 1);
 114         }
 115
 116         ar7_parts[2].name = "linux";
 117         ar7_parts[2].offset = pre_size;
 118         ar7_parts[2].size = master->size - pre_size - post_size;
 119         ar7_parts[2].mask_flags = 0;
 120
 121         ar7_parts[3].name = "rootfs";
 122         ar7_parts[3].offset = root_offset;
 123         ar7_parts[3].size = master->size - root_offset - post_size;
 124         ar7_parts[3].mask_flags = 0;
 125
 126         *pparts = ar7_parts;
 127         return AR7_PARTS;
 128 }
 129
 130 static struct mtd_part_parser ar7_parser = {
 131         .owner = THIS_MODULE,
 132         .parse_fn = create_mtd_partitions,
 133         .name = "ar7part",
 134 };
 135
 136 static int __init ar7_parser_init(void)
 137 {
 138         return register_mtd_parser(&ar7_parser);
 139 }
 140
 141 module_init(ar7_parser_init);
 142
 143 MODULE_LICENSE("GPL");
 144 MODULE_AUTHOR(  "Felix Fietkau <nbd@openwrt.org>, "
 145                 "Eugene Konev <ejka@openwrt.org>");
 146 MODULE_DESCRIPTION("MTD partitioning for TI AR7");