drivers/mtd/bcm63xxpart.c

   1 /*
   2  * BCM63XX CFE image tag parser
   3  *
   4  * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
   5  *                        Mike Albon <malbon@openwrt.org>
   6  * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
   7  * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  22  *
  23  */
  24
  25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  26
  27 #include <linux/bcm963xx_nvram.h>
  28 #include <linux/bcm963xx_tag.h>
  29 #include <linux/crc32.h>
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/sizes.h>
  33 #include <linux/slab.h>
  34 #include <linux/vmalloc.h>
  35 #include <linux/mtd/mtd.h>
  36 #include <linux/mtd/partitions.h>
  37 #include <linux/of.h>
  38
  39 #define BCM963XX_CFE_BLOCK_SIZE         SZ_64K  /* always at least 64KiB */
  40
  41 #define BCM963XX_CFE_MAGIC_OFFSET       0x4e0
  42 #define BCM963XX_CFE_VERSION_OFFSET     0x570
  43 #define BCM963XX_NVRAM_OFFSET           0x580
  44
  45 /* Ensure strings read from flash structs are null terminated */
  46 #define STR_NULL_TERMINATE(x) \
  47         do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
  48
  49 static int bcm63xx_detect_cfe(struct mtd_info *master)
  50 {
  51         char buf[9];
  52         int ret;
  53         size_t retlen;
  54
  55         ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  56                        (void *)buf);
  57         buf[retlen] = 0;
  58
  59         if (ret)
  60                 return ret;
  61
  62         if (strncmp("cfe-v", buf, 5) == 0)
  63                 return 0;
  64
  65         /* very old CFE's do not have the cfe-v string, so check for magic */
  66         ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
  67                        (void *)buf);
  68         buf[retlen] = 0;
  69
  70         return strncmp("CFE1CFE1", buf, 8);
  71 }
  72
  73 static int bcm63xx_read_nvram(struct mtd_info *master,
  74         struct bcm963xx_nvram *nvram)
  75 {
  76         u32 actual_crc, expected_crc;
  77         size_t retlen;
  78         int ret;
  79
  80         /* extract nvram data */
  81         ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
  82                         &retlen, (void *)nvram);
  83         if (ret)
  84                 return ret;
  85
  86         ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
  87         if (ret)
  88                 pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  89                         expected_crc, actual_crc);
  90
  91         if (!nvram->psi_size)
  92                 nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
  93
  94         return 0;
  95 }
  96
  97 static const char * const bcm63xx_cfe_part_types[] = {
  98         "bcm963xx-imagetag",
  99         NULL,
 100 };
 101
 102 static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
 103         const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
 104 {
 105         struct mtd_partition *parts;
 106         int nrparts = 3, curpart = 0;
 107         unsigned int cfelen, nvramlen;
 108         unsigned int cfe_erasesize;
 109         int i;
 110
 111         cfe_erasesize = max_t(uint32_t, master->erasesize,
 112                               BCM963XX_CFE_BLOCK_SIZE);
 113
 114         cfelen = cfe_erasesize;
 115         nvramlen = nvram->psi_size * SZ_1K;
 116         nvramlen = roundup(nvramlen, cfe_erasesize);
 117
 118         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 119         if (!parts)
 120                 return -ENOMEM;
 121
 122         /* Start building partition list */
 123         parts[curpart].name = "CFE";
 124         parts[curpart].offset = 0;
 125         parts[curpart].size = cfelen;
 126         curpart++;
 127
 128         parts[curpart].name = "nvram";
 129         parts[curpart].offset = master->size - nvramlen;
 130         parts[curpart].size = nvramlen;
 131         curpart++;
 132
 133         /* Global partition "linux" to make easy firmware upgrade */
 134         parts[curpart].name = "linux";
 135         parts[curpart].offset = cfelen;
 136         parts[curpart].size = master->size - cfelen - nvramlen;
 137         parts[curpart].types = bcm63xx_cfe_part_types;
 138
 139         for (i = 0; i < nrparts; i++)
 140                 pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 141                         parts[i].name, parts[i].offset, parts[i].size);
 142
 143         *pparts = parts;
 144
 145         return nrparts;
 146 }
 147
 148 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
 149                                         const struct mtd_partition **pparts,
 150                                         struct mtd_part_parser_data *data)
 151 {
 152         struct bcm963xx_nvram *nvram = NULL;
 153         int ret;
 154
 155         if (bcm63xx_detect_cfe(master))
 156                 return -EINVAL;
 157
 158         nvram = vzalloc(sizeof(*nvram));
 159         if (!nvram)
 160                 return -ENOMEM;
 161
 162         ret = bcm63xx_read_nvram(master, nvram);
 163         if (ret)
 164                 goto out;
 165
 166         if (!mtd_type_is_nand(master))
 167                 ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
 168         else
 169                 ret = -EINVAL;
 170
 171 out:
 172         vfree(nvram);
 173         return ret;
 174 };
 175
 176 static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
 177         { .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
 178         {},
 179 };
 180 MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);
 181
 182 static struct mtd_part_parser bcm63xx_cfe_parser = {
 183         .parse_fn = bcm63xx_parse_cfe_partitions,
 184         .name = "bcm63xxpart",
 185         .of_match_table = parse_bcm63xx_cfe_match_table,
 186 };
 187 module_mtd_part_parser(bcm63xx_cfe_parser);
 188
 189 MODULE_LICENSE("GPL");
 190 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 191 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 192 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 193 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 194 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");