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_tag.h>
  28 #include <linux/crc32.h>
  29 #include <linux/module.h>
  30 #include <linux/kernel.h>
  31 #include <linux/sizes.h>
  32 #include <linux/slab.h>
  33 #include <linux/vmalloc.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/partitions.h>
  36
  37 #include <asm/mach-bcm63xx/bcm63xx_nvram.h>
  38 #include <asm/mach-bcm63xx/board_bcm963xx.h>
  39
  40 #define BCM63XX_CFE_BLOCK_SIZE  SZ_64K          /* always at least 64KiB */
  41
  42 #define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
  43
  44 static int bcm63xx_detect_cfe(struct mtd_info *master)
  45 {
  46         char buf[9];
  47         int ret;
  48         size_t retlen;
  49
  50         ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  51                        (void *)buf);
  52         buf[retlen] = 0;
  53
  54         if (ret)
  55                 return ret;
  56
  57         if (strncmp("cfe-v", buf, 5) == 0)
  58                 return 0;
  59
  60         /* very old CFE's do not have the cfe-v string, so check for magic */
  61         ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
  62                        (void *)buf);
  63         buf[retlen] = 0;
  64
  65         return strncmp("CFE1CFE1", buf, 8);
  66 }
  67
  68 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
  69                                         const struct mtd_partition **pparts,
  70                                         struct mtd_part_parser_data *data)
  71 {
  72         /* CFE, NVRAM and global Linux are always present */
  73         int nrparts = 3, curpart = 0;
  74         struct bcm_tag *buf;
  75         struct mtd_partition *parts;
  76         int ret;
  77         size_t retlen;
  78         unsigned int rootfsaddr, kerneladdr, spareaddr;
  79         unsigned int rootfslen, kernellen, sparelen, totallen;
  80         unsigned int cfelen, nvramlen;
  81         unsigned int cfe_erasesize;
  82         int i;
  83         u32 computed_crc;
  84         bool rootfs_first = false;
  85
  86         if (bcm63xx_detect_cfe(master))
  87                 return -EINVAL;
  88
  89         cfe_erasesize = max_t(uint32_t, master->erasesize,
  90                               BCM63XX_CFE_BLOCK_SIZE);
  91
  92         cfelen = cfe_erasesize;
  93         nvramlen = bcm63xx_nvram_get_psi_size() * SZ_1K;
  94         nvramlen = roundup(nvramlen, cfe_erasesize);
  95
  96         /* Allocate memory for buffer */
  97         buf = vmalloc(sizeof(struct bcm_tag));
  98         if (!buf)
  99                 return -ENOMEM;
 100
 101         /* Get the tag */
 102         ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
 103                        (void *)buf);
 104
 105         if (retlen != sizeof(struct bcm_tag)) {
 106                 vfree(buf);
 107                 return -EIO;
 108         }
 109
 110         computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
 111                                 offsetof(struct bcm_tag, header_crc));
 112         if (computed_crc == buf->header_crc) {
 113                 char *boardid = &(buf->board_id[0]);
 114                 char *tagversion = &(buf->tag_version[0]);
 115
 116                 sscanf(buf->flash_image_start, "%u", &rootfsaddr);
 117                 sscanf(buf->kernel_address, "%u", &kerneladdr);
 118                 sscanf(buf->kernel_length, "%u", &kernellen);
 119                 sscanf(buf->total_length, "%u", &totallen);
 120
 121                 pr_info("CFE boot tag found with version %s and board type %s\n",
 122                         tagversion, boardid);
 123
 124                 kerneladdr = kerneladdr - BCM963XX_EXTENDED_SIZE;
 125                 rootfsaddr = rootfsaddr - BCM963XX_EXTENDED_SIZE;
 126                 spareaddr = roundup(totallen, master->erasesize) + cfelen;
 127
 128                 if (rootfsaddr < kerneladdr) {
 129                         /* default Broadcom layout */
 130                         rootfslen = kerneladdr - rootfsaddr;
 131                         rootfs_first = true;
 132                 } else {
 133                         /* OpenWrt layout */
 134                         rootfsaddr = kerneladdr + kernellen;
 135                         rootfslen = spareaddr - rootfsaddr;
 136                 }
 137         } else {
 138                 pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
 139                         buf->header_crc, computed_crc);
 140                 kernellen = 0;
 141                 rootfslen = 0;
 142                 rootfsaddr = 0;
 143                 spareaddr = cfelen;
 144         }
 145         sparelen = master->size - spareaddr - nvramlen;
 146
 147         /* Determine number of partitions */
 148         if (rootfslen > 0)
 149                 nrparts++;
 150
 151         if (kernellen > 0)
 152                 nrparts++;
 153
 154         /* Ask kernel for more memory */
 155         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 156         if (!parts) {
 157                 vfree(buf);
 158                 return -ENOMEM;
 159         }
 160
 161         /* Start building partition list */
 162         parts[curpart].name = "CFE";
 163         parts[curpart].offset = 0;
 164         parts[curpart].size = cfelen;
 165         curpart++;
 166
 167         if (kernellen > 0) {
 168                 int kernelpart = curpart;
 169
 170                 if (rootfslen > 0 && rootfs_first)
 171                         kernelpart++;
 172                 parts[kernelpart].name = "kernel";
 173                 parts[kernelpart].offset = kerneladdr;
 174                 parts[kernelpart].size = kernellen;
 175                 curpart++;
 176         }
 177
 178         if (rootfslen > 0) {
 179                 int rootfspart = curpart;
 180
 181                 if (kernellen > 0 && rootfs_first)
 182                         rootfspart--;
 183                 parts[rootfspart].name = "rootfs";
 184                 parts[rootfspart].offset = rootfsaddr;
 185                 parts[rootfspart].size = rootfslen;
 186                 if (sparelen > 0  && !rootfs_first)
 187                         parts[rootfspart].size += sparelen;
 188                 curpart++;
 189         }
 190
 191         parts[curpart].name = "nvram";
 192         parts[curpart].offset = master->size - nvramlen;
 193         parts[curpart].size = nvramlen;
 194         curpart++;
 195
 196         /* Global partition "linux" to make easy firmware upgrade */
 197         parts[curpart].name = "linux";
 198         parts[curpart].offset = cfelen;
 199         parts[curpart].size = master->size - cfelen - nvramlen;
 200
 201         for (i = 0; i < nrparts; i++)
 202                 pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 203                         parts[i].name, parts[i].offset, parts[i].size);
 204
 205         pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 206                 sparelen);
 207
 208         *pparts = parts;
 209         vfree(buf);
 210
 211         return nrparts;
 212 };
 213
 214 static struct mtd_part_parser bcm63xx_cfe_parser = {
 215         .parse_fn = bcm63xx_parse_cfe_partitions,
 216         .name = "bcm63xxpart",
 217 };
 218 module_mtd_part_parser(bcm63xx_cfe_parser);
 219
 220 MODULE_LICENSE("GPL");
 221 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 222 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 223 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 224 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 225 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");