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

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