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