target/linux/ar7-2.6/files/drivers/mtd/ar7part.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright (C) 2007 OpenWrt.org
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * TI AR7 flash partition table.
  21  * Based on ar7 map by Felix Fietkau.
  22  *
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/slab.h>
  27
  28 #include <linux/mtd/mtd.h>
  29 #include <linux/mtd/partitions.h>
  30 #include <linux/bootmem.h>
  31 #include <linux/squashfs_fs.h>
  32
  33 struct ar7_bin_rec {
  34         unsigned int checksum;
  35         unsigned int length;
  36         unsigned int address;
  37 };
  38
  39 static struct mtd_partition ar7_parts[5];
  40
  41 static int create_mtd_partitions(struct mtd_info *master,
  42                                  struct mtd_partition **pparts,
  43                                  unsigned long origin)
  44 {
  45         struct ar7_bin_rec header;
  46         unsigned int offset, len;
  47         unsigned int pre_size = master->erasesize, post_size = 0,
  48                 root_offset = 0xe0000;
  49         int retries = 10;
  50
  51         printk("Parsing AR7 partition map...\n");
  52
  53         ar7_parts[0].name = "loader";
  54         ar7_parts[0].offset = 0;
  55         ar7_parts[0].size = master->erasesize;
  56         ar7_parts[0].mask_flags = MTD_WRITEABLE;
  57
  58         ar7_parts[1].name = "config";
  59         ar7_parts[1].offset = 0;
  60         ar7_parts[1].size = master->erasesize;
  61         ar7_parts[1].mask_flags = 0;
  62
  63         do {
  64                 offset = pre_size;
  65                 master->read(master, offset, sizeof(header), &len, (u_char *)&header);
  66                 if (!strncmp((char *)&header, "TIENV0.8", 8))
  67                         ar7_parts[1].offset = pre_size;
  68                 if (header.checksum == 0xfeedfa42)
  69                         break;
  70                 if (header.checksum == 0xfeed1281)
  71                         break;
  72                 pre_size += master->erasesize;
  73         } while (retries--);
  74
  75         pre_size = offset;
  76
  77         if (!ar7_parts[1].offset) {
  78                 ar7_parts[1].offset = master->size - master->erasesize;
  79                 post_size = master->erasesize;
  80         }
  81
  82         switch (header.checksum) {
  83         case 0xfeedfa42:
  84                 while (header.length) {
  85                         offset += sizeof(header) + header.length;
  86                         master->read(master, offset, sizeof(header),
  87                                      &len, (u_char *)&header);
  88                 }
  89                 root_offset = offset + sizeof(header) + 4;
  90                 break;
  91         case 0xfeed1281:
  92                 while (header.length) {
  93                         offset += sizeof(header) + header.length;
  94                         master->read(master, offset, sizeof(header),
  95                                      &len, (u_char *)&header);
  96                 }
  97                 root_offset = offset + sizeof(header) + 4 + 0xff;
  98                 root_offset &= ~(u32)0xff;
  99                 break;
 100         default:
 101                 printk("Unknown magic: %08x\n", header.checksum);
 102                 break;
 103         }
 104
 105         master->read(master, root_offset, sizeof(header), &len, (u_char *)&header);
 106         if (header.checksum != SQUASHFS_MAGIC) {
 107                 root_offset += master->erasesize - 1;
 108                 root_offset &= ~(master->erasesize - 1);
 109         }
 110
 111         ar7_parts[2].name = "linux";
 112         ar7_parts[2].offset = pre_size;
 113         ar7_parts[2].size = master->size - pre_size - post_size;
 114         ar7_parts[2].mask_flags = 0;
 115
 116         ar7_parts[3].name = "rootfs";
 117         ar7_parts[3].offset = root_offset;
 118         ar7_parts[3].size = master->size - root_offset - post_size;
 119         ar7_parts[3].mask_flags = 0;
 120
 121         *pparts = ar7_parts;
 122         return 4;
 123 }
 124
 125 static struct mtd_part_parser ar7_parser = {
 126         .owner = THIS_MODULE,
 127         .parse_fn = create_mtd_partitions,
 128         .name = "ar7part",
 129 };
 130
 131 static int __init ar7_parser_init(void)
 132 {
 133         return register_mtd_parser(&ar7_parser);
 134 }
 135
 136 module_init(ar7_parser_init);
 137
 138 MODULE_LICENSE("GPL");
 139 MODULE_AUTHOR("Felix Fietkau, Eugene Konev");
 140 MODULE_DESCRIPTION("MTD partitioning for TI AR7");