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/crc32.h>
  28 #include <linux/module.h>
  29 #include <linux/kernel.h>
  30 #include <linux/sizes.h>
  31 #include <linux/slab.h>
  32 #include <linux/vmalloc.h>
  33 #include <linux/mtd/mtd.h>
  34 #include <linux/mtd/partitions.h>
  35
  36 #include <asm/mach-bcm63xx/bcm63xx_nvram.h>
  37 #include <asm/mach-bcm63xx/bcm963xx_tag.h>
  38 #include <asm/mach-bcm63xx/board_bcm963xx.h>
  39
  40 #define BCM63XX_EXTENDED_SIZE   0xBFC00000      /* Extended flash address */
  41
  42 #define BCM63XX_CFE_BLOCK_SIZE  SZ_64K          /* always at least 64KiB */
  43
  44 #define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
  45
  46 static int bcm63xx_detect_cfe(struct mtd_info *master)
  47 {
  48         char buf[9];
  49         int ret;
  50         size_t retlen;
  51
  52         ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  53                        (void *)buf);
  54         buf[retlen] = 0;
  55
  56         if (ret)
  57                 return ret;
  58
  59         if (strncmp("cfe-v", buf, 5) == 0)
  60                 return 0;
  61
  62         /* very old CFE's do not have the cfe-v string, so check for magic */
  63         ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
  64                        (void *)buf);
  65         buf[retlen] = 0;
  66
  67         return strncmp("CFE1CFE1", buf, 8);
  68 }
  69
  70 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
  71                                         struct mtd_partition **pparts,
  72                                         struct mtd_part_parser_data *data)
  73 {
  74         /* CFE, NVRAM and global Linux are always present */
  75         int nrparts = 3, curpart = 0;
  76         struct bcm_tag *buf;
  77         struct mtd_partition *parts;
  78         int ret;
  79         size_t retlen;
  80         unsigned int rootfsaddr, kerneladdr, spareaddr;
  81         unsigned int rootfslen, kernellen, sparelen, totallen;
  82         unsigned int cfelen, nvramlen;
  83         unsigned int cfe_erasesize;
  84         int i;
  85         u32 computed_crc;
  86         bool rootfs_first = false;
  87
  88         if (bcm63xx_detect_cfe(master))
  89                 return -EINVAL;
  90
  91         cfe_erasesize = max_t(uint32_t, master->erasesize,
  92                               BCM63XX_CFE_BLOCK_SIZE);
  93
  94         cfelen = cfe_erasesize;
  95         nvramlen = bcm63xx_nvram_get_psi_size() * SZ_1K;
  96         nvramlen = roundup(nvramlen, cfe_erasesize);
  97
  98         /* Allocate memory for buffer */
  99         buf = vmalloc(sizeof(struct bcm_tag));
 100         if (!buf)
 101                 return -ENOMEM;
 102
 103         /* Get the tag */
 104         ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
 105                        (void *)buf);
 106
 107         if (retlen != sizeof(struct bcm_tag)) {
 108                 vfree(buf);
 109                 return -EIO;
 110         }
 111
 112         computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
 113                                 offsetof(struct bcm_tag, header_crc));
 114         if (computed_crc == buf->header_crc) {
 115                 char *boardid = &(buf->board_id[0]);
 116                 char *tagversion = &(buf->tag_version[0]);
 117
 118                 sscanf(buf->flash_image_start, "%u", &rootfsaddr);
 119                 sscanf(buf->kernel_address, "%u", &kerneladdr);
 120                 sscanf(buf->kernel_length, "%u", &kernellen);
 121                 sscanf(buf->total_length, "%u", &totallen);
 122
 123                 pr_info("CFE boot tag found with version %s and board type %s\n",
 124                         tagversion, boardid);
 125
 126                 kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
 127                 rootfsaddr = rootfsaddr - BCM63XX_EXTENDED_SIZE;
 128                 spareaddr = roundup(totallen, master->erasesize) + cfelen;
 129
 130                 if (rootfsaddr < kerneladdr) {
 131                         /* default Broadcom layout */
 132                         rootfslen = kerneladdr - rootfsaddr;
 133                         rootfs_first = true;
 134                 } else {
 135                         /* OpenWrt layout */
 136                         rootfsaddr = kerneladdr + kernellen;
 137                         rootfslen = spareaddr - rootfsaddr;
 138                 }
 139         } else {
 140                 pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
 141                         buf->header_crc, computed_crc);
 142                 kernellen = 0;
 143                 rootfslen = 0;
 144                 rootfsaddr = 0;
 145                 spareaddr = cfelen;
 146         }
 147         sparelen = master->size - spareaddr - nvramlen;
 148
 149         /* Determine number of partitions */
 150         if (rootfslen > 0)
 151                 nrparts++;
 152
 153         if (kernellen > 0)
 154                 nrparts++;
 155
 156         /* Ask kernel for more memory */
 157         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 158         if (!parts) {
 159                 vfree(buf);
 160                 return -ENOMEM;
 161         }
 162
 163         /* Start building partition list */
 164         parts[curpart].name = "CFE";
 165         parts[curpart].offset = 0;
 166         parts[curpart].size = cfelen;
 167         curpart++;
 168
 169         if (kernellen > 0) {
 170                 int kernelpart = curpart;
 171
 172                 if (rootfslen > 0 && rootfs_first)
 173                         kernelpart++;
 174                 parts[kernelpart].name = "kernel";
 175                 parts[kernelpart].offset = kerneladdr;
 176                 parts[kernelpart].size = kernellen;
 177                 curpart++;
 178         }
 179
 180         if (rootfslen > 0) {
 181                 int rootfspart = curpart;
 182
 183                 if (kernellen > 0 && rootfs_first)
 184                         rootfspart--;
 185                 parts[rootfspart].name = "rootfs";
 186                 parts[rootfspart].offset = rootfsaddr;
 187                 parts[rootfspart].size = rootfslen;
 188                 if (sparelen > 0  && !rootfs_first)
 189                         parts[rootfspart].size += sparelen;
 190                 curpart++;
 191         }
 192
 193         parts[curpart].name = "nvram";
 194         parts[curpart].offset = master->size - nvramlen;
 195         parts[curpart].size = nvramlen;
 196         curpart++;
 197
 198         /* Global partition "linux" to make easy firmware upgrade */
 199         parts[curpart].name = "linux";
 200         parts[curpart].offset = cfelen;
 201         parts[curpart].size = master->size - cfelen - nvramlen;
 202
 203         for (i = 0; i < nrparts; i++)
 204                 pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 205                         parts[i].name, parts[i].offset, parts[i].size);
 206
 207         pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 208                 sparelen);
 209
 210         *pparts = parts;
 211         vfree(buf);
 212
 213         return nrparts;
 214 };
 215
 216 static struct mtd_part_parser bcm63xx_cfe_parser = {
 217         .owner = THIS_MODULE,
 218         .parse_fn = bcm63xx_parse_cfe_partitions,
 219         .name = "bcm63xxpart",
 220 };
 221
 222 static int __init bcm63xx_cfe_parser_init(void)
 223 {
 224         register_mtd_parser(&bcm63xx_cfe_parser);
 225         return 0;
 226 }
 227
 228 static void __exit bcm63xx_cfe_parser_exit(void)
 229 {
 230         deregister_mtd_parser(&bcm63xx_cfe_parser);
 231 }
 232
 233 module_init(bcm63xx_cfe_parser_init);
 234 module_exit(bcm63xx_cfe_parser_exit);
 235
 236 MODULE_LICENSE("GPL");
 237 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 238 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 239 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 240 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 241 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");