target/linux/adm5120/files-2.6.26/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) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
   6  *
   7  *  This file was based on drivers/mtd/redboot.c
   8  *  Author: Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify it
  11  *  under the terms of the GNU General Public License version 2 as published
  12  *  by the Free Software Foundation.
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18 #include <linux/init.h>
  19 #include <linux/vmalloc.h>
  20
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/partitions.h>
  23
  24 #include <linux/byteorder/generic.h>
  25
  26 #include <prom/myloader.h>
  27
  28 #define NAME_LEN_MAX            20
  29 #define NAME_MYLOADER           "MyLoader"
  30 #define NAME_PARTITION_TABLE    "Partition Table"
  31 #define BLOCK_LEN_MIN           0x10000
  32
  33 int parse_myloader_partitions(struct mtd_info *master,
  34                         struct mtd_partition **pparts,
  35                         unsigned long origin)
  36 {
  37         struct mylo_partition_table *tab;
  38         struct mylo_partition *part;
  39         struct mtd_partition *mtd_parts;
  40         struct mtd_partition *mtd_part;
  41         int num_parts;
  42         int ret, i;
  43         size_t retlen;
  44         char *names;
  45         unsigned long offset;
  46         unsigned long blocklen;
  47
  48         tab = vmalloc(sizeof(*tab));
  49         if (!tab) {
  50                 return -ENOMEM;
  51                 goto out;
  52         }
  53
  54         blocklen = master->erasesize;
  55         if (blocklen < BLOCK_LEN_MIN)
  56                 blocklen = BLOCK_LEN_MIN;
  57
  58         /* Partition Table is always located on the second erase block */
  59         offset = blocklen;
  60         printk(KERN_NOTICE "%s: searching for MyLoader partition table at "
  61                         "offset 0x%lx\n", master->name, offset);
  62
  63         ret = master->read(master, offset, sizeof(*tab), &retlen, (void *)tab);
  64         if (ret)
  65                 goto out;
  66
  67         if (retlen != sizeof(*tab)) {
  68                 ret = -EIO;
  69                 goto out_free_buf;
  70         }
  71
  72         /* Check for Partition Table magic number */
  73         if (tab->magic != le32_to_cpu(MYLO_MAGIC_PARTITIONS)) {
  74                 printk(KERN_NOTICE "%s: no MyLoader partition table found\n",
  75                         master->name);
  76                 ret = 0;
  77                 goto out_free_buf;
  78         }
  79
  80         /* The MyLoader and the Partition Table is always present */
  81         num_parts = 2;
  82
  83         /* Detect number of used partitions */
  84         for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
  85                 part = &tab->partitions[i];
  86
  87                 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
  88                         continue;
  89
  90                 num_parts++;
  91         }
  92
  93         mtd_parts = kzalloc((num_parts * sizeof(*mtd_part) +
  94                                 num_parts * NAME_LEN_MAX), GFP_KERNEL);
  95
  96         if (!mtd_parts) {
  97                 ret = -ENOMEM;
  98                 goto out_free_buf;
  99         }
 100
 101         mtd_part = mtd_parts;
 102         names = (char *)&mtd_parts[num_parts];
 103
 104         strncpy(names, NAME_MYLOADER, NAME_LEN_MAX-1);
 105         mtd_part->name = names;
 106         mtd_part->offset = 0;
 107         mtd_part->size = blocklen;
 108         mtd_part->mask_flags = MTD_WRITEABLE;
 109         mtd_part++;
 110         names += NAME_LEN_MAX;
 111
 112         strncpy(names, NAME_PARTITION_TABLE, NAME_LEN_MAX-1);
 113         mtd_part->name = names;
 114         mtd_part->offset = blocklen;
 115         mtd_part->size = blocklen;
 116         mtd_part->mask_flags = MTD_WRITEABLE;
 117         mtd_part++;
 118         names += NAME_LEN_MAX;
 119
 120         for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
 121                 part = &tab->partitions[i];
 122
 123                 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
 124                         continue;
 125
 126                 sprintf(names, "partition%d", i);
 127                 mtd_part->offset = le32_to_cpu(part->addr);
 128                 mtd_part->size = le32_to_cpu(part->size);
 129                 mtd_part->name = names;
 130                 mtd_part++;
 131                 names += NAME_LEN_MAX;
 132         }
 133
 134         *pparts = mtd_parts;
 135         ret = num_parts;
 136
 137 out_free_buf:
 138         vfree(tab);
 139 out:
 140         return ret;
 141 }
 142
 143 static struct mtd_part_parser mylo_mtd_parser = {
 144         .owner = THIS_MODULE,
 145         .parse_fn = parse_myloader_partitions,
 146         .name = NAME_MYLOADER,
 147 };
 148
 149 static int __init mylo_mtd_parser_init(void)
 150 {
 151         return register_mtd_parser(&mylo_mtd_parser);
 152 }
 153
 154 static void __exit mylo_mtd_parser_exit(void)
 155 {
 156         deregister_mtd_parser(&mylo_mtd_parser);
 157 }
 158
 159 module_init(mylo_mtd_parser_init);
 160 module_exit(mylo_mtd_parser_exit);
 161
 162 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 163 MODULE_DESCRIPTION("Parsing code for MyLoader partition tables");
 164 MODULE_LICENSE("GPL v2");