target/linux/adm5120-2.6/files/drivers/mtd/myloader.c

   1 /*
   2  *  Parse MyLoader-style flash partition tables and produce a Linux partition
   3  *  array to match.
   4  *
   5  *  Copyright (C) 2007 OpenWrt.org
   6  *  Copyright (C) 2007 Gabor Juhos <juhosg@freemail.hu>
   7  *
   8  *  This file was based on drivers/mtd/redboot.c
   9  *  Author: Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>
  10  *
  11  *  This program is free software; you can redistribute it and/or
  12  *  modify it under the terms of the GNU General Public License
  13  *  as published by the Free Software Foundation; either version 2
  14  *  of the License, or (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to the
  23  *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24  *  Boston, MA  02110-1301, USA.
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/slab.h>
  29 #include <linux/init.h>
  30 #include <linux/vmalloc.h>
  31
  32 #include <linux/mtd/mtd.h>
  33 #include <linux/mtd/partitions.h>
  34
  35 #include <linux/byteorder/generic.h>
  36 #include <asm/mach-adm5120/myloader.h>
  37
  38 #define NAME_LEN_MAX            20
  39 #define NAME_MYLOADER           "MyLoader"
  40 #define NAME_PARTITION_TABLE    "Partition Table"
  41 #define BLOCK_LEN_MIN           0x10000
  42
  43 static int parse_myloader_partitions(struct mtd_info *master,
  44                         struct mtd_partition **pparts,
  45                         unsigned long origin)
  46 {
  47         struct mylo_partition_table *tab;
  48         struct mylo_partition *part;
  49         struct mtd_partition *mtd_parts;
  50         struct mtd_partition *mtd_part;
  51         int num_parts;
  52         int ret, i;
  53         size_t retlen;
  54         size_t parts_len;
  55         char *names;
  56         unsigned long offset;
  57         unsigned long blocklen;
  58
  59         tab = vmalloc(sizeof(*tab));
  60         if (!tab) {
  61                 return -ENOMEM;
  62                 goto out;
  63         }
  64
  65         blocklen = master->erasesize;
  66         if (blocklen < BLOCK_LEN_MIN)
  67                 blocklen = BLOCK_LEN_MIN;
  68
  69         /* Partition Table is always located on the second erase block */
  70         offset = blocklen;
  71         printk(KERN_NOTICE "Searching for MyLoader partition table "
  72                         "in %s at offset 0x%lx\n", master->name, offset);
  73
  74         ret = master->read(master, offset, sizeof(*tab), &retlen,
  75                         (void *)tab);
  76
  77         if (ret)
  78                 goto out;
  79
  80         if (retlen != sizeof(*tab)) {
  81                 ret = -EIO;
  82                 goto out_free_buf;
  83         }
  84
  85         /* Check for Partition Table magic number */
  86         if (tab->magic != le32_to_cpu(MYLO_MAGIC_PARTITIONS)) {
  87                 printk(KERN_NOTICE "No MyLoader partition table detected "
  88                         "in %s\n", master->name);
  89                 ret = 0;
  90                 goto out_free_buf;
  91         }
  92
  93         /* The MyLoader and the Partition Table is always present */
  94         num_parts = 2;
  95
  96         /* Detect number of used partitions */
  97         for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
  98                 part = &tab->partitions[i];
  99
 100                 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
 101                         continue;
 102
 103                 num_parts++;
 104         }
 105
 106
 107         mtd_parts = kzalloc((num_parts*sizeof(*mtd_part) + num_parts*NAME_LEN_MAX),
 108                          GFP_KERNEL);
 109
 110         if (!mtd_parts) {
 111                 ret = -ENOMEM;
 112                 goto out_free_buf;
 113         }
 114
 115         mtd_part = mtd_parts;
 116         names = (char *)&mtd_parts[num_parts];
 117
 118         strcpy(NAME_MYLOADER, names);
 119         mtd_part->name = names;
 120         mtd_part->offset = 0;
 121         mtd_part->size = blocklen;
 122         mtd_part++;
 123         names += NAME_LEN_MAX;
 124
 125         strcpy(NAME_PARTITION_TABLE, names);
 126         mtd_part->name = names;
 127         mtd_part->offset = blocklen;
 128         mtd_part->size = blocklen;
 129         mtd_part++;
 130         names += NAME_LEN_MAX;
 131
 132         for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
 133                 part = &tab->partitions[i];
 134
 135                 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
 136                         continue;
 137
 138                 sprintf(names, "partition%d", i);
 139                 mtd_part->name = names;
 140                 mtd_part->offset = le32_to_cpu(part->addr);
 141                 mtd_part->size = le32_to_cpu(part->size);
 142                 mtd_part++;
 143                 names += NAME_LEN_MAX;
 144         }
 145
 146         *pparts = mtd_parts;
 147         ret = num_parts;
 148
 149 out_free_buf:
 150         vfree(tab);
 151 out:
 152         return ret;
 153 }
 154
 155 static struct mtd_part_parser mylo_mtd_parser = {
 156         .owner = THIS_MODULE,
 157         .parse_fn = parse_myloader_partitions,
 158         .name = NAME_MYLOADER,
 159 };
 160
 161 static int __init mylo_mtd_parser_init(void)
 162 {
 163         return register_mtd_parser(&mylo_mtd_parser);
 164 }
 165
 166 static void __exit mylo_mtd_parser_exit(void)
 167 {
 168         deregister_mtd_parser(&mylo_mtd_parser);
 169 }
 170
 171 module_init(mylo_mtd_parser_init);
 172 module_exit(mylo_mtd_parser_exit);
 173
 174 EXPORT_SYMBOL_GPL(parse_myloader_partitions);
 175
 176 MODULE_AUTHOR("Gabor Juhos <juhosg@freemail.hu>");
 177 MODULE_DESCRIPTION("Parsing code for MyLoader partition tables");
 178 MODULE_LICENSE("GPL");