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 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/crc32.h>
  28 #include <linux/module.h>
  29 #include <linux/kernel.h>
  30 #include <linux/slab.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/mtd/mtd.h>
  33 #include <linux/mtd/partitions.h>
  34
  35 #include <asm/mach-bcm63xx/bcm963xx_tag.h>
  36 #include <asm/mach-bcm63xx/board_bcm963xx.h>
  37
  38 #define BCM63XX_EXTENDED_SIZE   0xBFC00000      /* Extended flash address */
  39
  40 #define BCM63XX_MIN_CFE_SIZE    0x10000         /* always at least 64KiB */
  41 #define BCM63XX_MIN_NVRAM_SIZE  0x10000         /* always at least 64KiB */
  42
  43 #define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
  44
  45 static int bcm63xx_detect_cfe(struct mtd_info *master)
  46 {
  47         char buf[9];
  48         int ret;
  49         size_t retlen;
  50
  51         ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  52                        (void *)buf);
  53         buf[retlen] = 0;
  54
  55         if (ret)
  56                 return ret;
  57
  58         if (strncmp("cfe-v", buf, 5) == 0)
  59                 return 0;
  60
  61         /* very old CFE's do not have the cfe-v string, so check for magic */
  62         ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
  63                        (void *)buf);
  64         buf[retlen] = 0;
  65
  66         return strncmp("CFE1CFE1", buf, 8);
  67 }
  68
  69 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
  70                                         struct mtd_partition **pparts,
  71                                         struct mtd_part_parser_data *data)
  72 {
  73         /* CFE, NVRAM and global Linux are always present */
  74         int nrparts = 3, curpart = 0;
  75         struct bcm_tag *buf;
  76         struct mtd_partition *parts;
  77         int ret;
  78         size_t retlen;
  79         unsigned int rootfsaddr, kerneladdr, spareaddr;
  80         unsigned int rootfslen, kernellen, sparelen, totallen;
  81         unsigned int cfelen, nvramlen;
  82         int namelen = 0;
  83         int i;
  84         u32 computed_crc;
  85
  86         if (bcm63xx_detect_cfe(master))
  87                 return -EINVAL;
  88
  89         cfelen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_CFE_SIZE);
  90         nvramlen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_NVRAM_SIZE);
  91
  92         /* Allocate memory for buffer */
  93         buf = vmalloc(sizeof(struct bcm_tag));
  94         if (!buf)
  95                 return -ENOMEM;
  96
  97         /* Get the tag */
  98         ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
  99                        (void *)buf);
 100
 101         if (retlen != sizeof(struct bcm_tag)) {
 102                 vfree(buf);
 103                 return -EIO;
 104         }
 105
 106         computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
 107                                 offsetof(struct bcm_tag, header_crc));
 108         if (computed_crc == buf->header_crc) {
 109                 char *boardid = &(buf->board_id[0]);
 110                 char *tagversion = &(buf->tag_version[0]);
 111
 112                 sscanf(buf->kernel_address, "%u", &kerneladdr);
 113                 sscanf(buf->kernel_length, "%u", &kernellen);
 114                 sscanf(buf->total_length, "%u", &totallen);
 115
 116                 pr_info("CFE boot tag found with version %s and board type %s\n",
 117                         tagversion, boardid);
 118
 119                 kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
 120                 rootfsaddr = kerneladdr + kernellen;
 121                 spareaddr = roundup(totallen, master->erasesize) + cfelen;
 122                 sparelen = master->size - spareaddr - nvramlen;
 123                 rootfslen = spareaddr - rootfsaddr;
 124         } else {
 125                 pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
 126                         buf->header_crc, computed_crc);
 127                 kernellen = 0;
 128                 rootfslen = 0;
 129                 rootfsaddr = 0;
 130                 spareaddr = cfelen;
 131                 sparelen = master->size - cfelen - nvramlen;
 132         }
 133
 134         /* Determine number of partitions */
 135         namelen = 8;
 136         if (rootfslen > 0) {
 137                 nrparts++;
 138                 namelen += 6;
 139         }
 140         if (kernellen > 0) {
 141                 nrparts++;
 142                 namelen += 6;
 143         }
 144
 145         /* Ask kernel for more memory */
 146         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 147         if (!parts) {
 148                 vfree(buf);
 149                 return -ENOMEM;
 150         }
 151
 152         /* Start building partition list */
 153         parts[curpart].name = "CFE";
 154         parts[curpart].offset = 0;
 155         parts[curpart].size = cfelen;
 156         curpart++;
 157
 158         if (kernellen > 0) {
 159                 parts[curpart].name = "kernel";
 160                 parts[curpart].offset = kerneladdr;
 161                 parts[curpart].size = kernellen;
 162                 curpart++;
 163         }
 164
 165         if (rootfslen > 0) {
 166                 parts[curpart].name = "rootfs";
 167                 parts[curpart].offset = rootfsaddr;
 168                 parts[curpart].size = rootfslen;
 169                 if (sparelen > 0)
 170                         parts[curpart].size += sparelen;
 171                 curpart++;
 172         }
 173
 174         parts[curpart].name = "nvram";
 175         parts[curpart].offset = master->size - nvramlen;
 176         parts[curpart].size = nvramlen;
 177
 178         /* Global partition "linux" to make easy firmware upgrade */
 179         curpart++;
 180         parts[curpart].name = "linux";
 181         parts[curpart].offset = cfelen;
 182         parts[curpart].size = master->size - cfelen - nvramlen;
 183
 184         for (i = 0; i < nrparts; i++)
 185                 pr_info("Partition %d is %s offset %lx and length %lx\n", i,
 186                         parts[i].name, (long unsigned int)(parts[i].offset),
 187                         (long unsigned int)(parts[i].size));
 188
 189         pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 190                 sparelen);
 191
 192         *pparts = parts;
 193         vfree(buf);
 194
 195         return nrparts;
 196 };
 197
 198 static struct mtd_part_parser bcm63xx_cfe_parser = {
 199         .owner = THIS_MODULE,
 200         .parse_fn = bcm63xx_parse_cfe_partitions,
 201         .name = "bcm63xxpart",
 202 };
 203
 204 static int __init bcm63xx_cfe_parser_init(void)
 205 {
 206         return register_mtd_parser(&bcm63xx_cfe_parser);
 207 }
 208
 209 static void __exit bcm63xx_cfe_parser_exit(void)
 210 {
 211         deregister_mtd_parser(&bcm63xx_cfe_parser);
 212 }
 213
 214 module_init(bcm63xx_cfe_parser_init);
 215 module_exit(bcm63xx_cfe_parser_exit);
 216
 217 MODULE_LICENSE("GPL");
 218 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 219 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 220 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 221 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 222 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");