target/linux/at91-2.6/files/drivers/mtd/at91part.c

   1 /*
   2  * $Id: at91part.c 6948 2007-04-15 04:01:45Z hcg $
   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  * Atmel AT91 flash partition table. (Modified by Hamish Guthrie).
  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 static struct mtd_partition at91_parts[6];
  34
  35 static int create_mtd_partitions(struct mtd_info *master,
  36                                  struct mtd_partition **pparts,
  37                                  unsigned long origin)
  38 {
  39         unsigned int offset, len;
  40         unsigned int pre_size = 0x42000, root_max = 0x362400;
  41         unsigned char buf[512];
  42         struct squashfs_super_block *sb = (struct squashfs_super_block *) buf;
  43
  44         printk("Parsing AT91 partition map...\n");
  45
  46         at91_parts[0].name = "loaders";
  47         at91_parts[0].offset = 0;
  48         at91_parts[0].size = 0x21000;
  49         at91_parts[0].mask_flags = MTD_WRITEABLE;
  50
  51         at91_parts[1].name = "ubparams";
  52         at91_parts[1].offset = 0x21000;
  53         at91_parts[1].size = 0x8400;
  54         at91_parts[1].mask_flags = 0;
  55
  56         at91_parts[2].name = "kernel";
  57         at91_parts[2].offset = pre_size;
  58         at91_parts[2].size = 0;
  59         at91_parts[2].mask_flags = 0;
  60
  61         at91_parts[3].name = "rootfs";
  62         at91_parts[3].offset = 0;
  63         at91_parts[3].size = 0;
  64         at91_parts[3].mask_flags = 0;
  65
  66         for(offset = pre_size; offset < root_max; offset += master->erasesize) {
  67
  68                 memset(&buf, 0xe5, sizeof(buf));
  69
  70                 if (master->read(master, offset, sizeof(buf), &len, buf) || len != sizeof(buf))
  71                         break;
  72
  73                 if (*((__u32 *) buf) == SQUASHFS_MAGIC) {
  74                         printk(KERN_INFO "%s: Filesystem type: squashfs, size=0x%x\n",
  75                                                         master->name, (u32) sb->bytes_used);
  76
  77                         at91_parts[3].size = sb->bytes_used;
  78                         at91_parts[3].offset = offset;
  79                         len = at91_parts[3].offset + at91_parts[3].size;
  80                         len = ((len / (master->erasesize * 8)) + 1) * master->erasesize * 8;
  81                         at91_parts[3].size = len - at91_parts[3].offset;
  82                         at91_parts[2].size = offset - at91_parts[2].offset;
  83                         break;
  84                         }
  85                 }
  86
  87         if (at91_parts[3].size == 0) {
  88                 printk(KERN_NOTICE "%s: Couldn't find root filesystem\n", master->name);
  89                 return -1;
  90                 }
  91
  92         at91_parts[4].name = "rootfs_data";
  93         at91_parts[4].offset = root_max;
  94         at91_parts[4].size = master->size - root_max;
  95         at91_parts[4].mask_flags = 0;
  96
  97         at91_parts[5].name = "complete";
  98         at91_parts[5].offset = 0;
  99         at91_parts[5].size = master->size;
 100         at91_parts[5].mask_flags = 0;
 101
 102         *pparts = at91_parts;
 103         return 6;
 104 }
 105
 106 static struct mtd_part_parser at91_parser = {
 107         .owner = THIS_MODULE,
 108         .parse_fn = create_mtd_partitions,
 109         .name = "at91part",
 110 };
 111
 112 static int __init at91_parser_init(void)
 113 {
 114         return register_mtd_parser(&at91_parser);
 115 }
 116
 117 module_init(at91_parser_init);
 118
 119 MODULE_LICENSE("GPL");
 120 MODULE_AUTHOR("Felix Fietkau, Eugene Konev, Hamish Guthrie");
 121 MODULE_DESCRIPTION("MTD partitioning for Atmel at91");