linux/drivers/mtd/bcm63xxpart.c
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   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
  38#define BCM963XX_CFE_BLOCK_SIZE         SZ_64K  /* always at least 64KiB */
  39
  40#define BCM963XX_CFE_MAGIC_OFFSET       0x4e0
  41#define BCM963XX_CFE_VERSION_OFFSET     0x570
  42#define BCM963XX_NVRAM_OFFSET           0x580
  43
  44/* Ensure strings read from flash structs are null terminated */
  45#define STR_NULL_TERMINATE(x) \
  46        do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
  47
  48static int bcm63xx_detect_cfe(struct mtd_info *master)
  49{
  50        char buf[9];
  51        int ret;
  52        size_t retlen;
  53
  54        ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  55                       (void *)buf);
  56        buf[retlen] = 0;
  57
  58        if (ret)
  59                return ret;
  60
  61        if (strncmp("cfe-v", buf, 5) == 0)
  62                return 0;
  63
  64        /* very old CFE's do not have the cfe-v string, so check for magic */
  65        ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
  66                       (void *)buf);
  67        buf[retlen] = 0;
  68
  69        return strncmp("CFE1CFE1", buf, 8);
  70}
  71
  72static int bcm63xx_read_nvram(struct mtd_info *master,
  73        struct bcm963xx_nvram *nvram)
  74{
  75        u32 actual_crc, expected_crc;
  76        size_t retlen;
  77        int ret;
  78
  79        /* extract nvram data */
  80        ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
  81                        &retlen, (void *)nvram);
  82        if (ret)
  83                return ret;
  84
  85        ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
  86        if (ret)
  87                pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  88                        expected_crc, actual_crc);
  89
  90        if (!nvram->psi_size)
  91                nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
  92
  93        return 0;
  94}
  95
  96static int bcm63xx_read_image_tag(struct mtd_info *master, const char *name,
  97        loff_t tag_offset, struct bcm_tag *buf)
  98{
  99        int ret;
 100        size_t retlen;
 101        u32 computed_crc;
 102
 103        ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
 104        if (ret)
 105                return ret;
 106
 107        if (retlen != sizeof(*buf))
 108                return -EIO;
 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                STR_NULL_TERMINATE(buf->board_id);
 114                STR_NULL_TERMINATE(buf->tag_version);
 115
 116                pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
 117                        name, tag_offset, buf->tag_version, buf->board_id);
 118
 119                return 0;
 120        }
 121
 122        pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
 123                name, tag_offset, buf->header_crc, computed_crc);
 124        return 1;
 125}
 126
 127static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
 128        const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
 129{
 130        /* CFE, NVRAM and global Linux are always present */
 131        int nrparts = 3, curpart = 0;
 132        struct bcm_tag *buf = NULL;
 133        struct mtd_partition *parts;
 134        int ret;
 135        unsigned int rootfsaddr, kerneladdr, spareaddr;
 136        unsigned int rootfslen, kernellen, sparelen, totallen;
 137        unsigned int cfelen, nvramlen;
 138        unsigned int cfe_erasesize;
 139        int i;
 140        bool rootfs_first = false;
 141
 142        cfe_erasesize = max_t(uint32_t, master->erasesize,
 143                              BCM963XX_CFE_BLOCK_SIZE);
 144
 145        cfelen = cfe_erasesize;
 146        nvramlen = nvram->psi_size * SZ_1K;
 147        nvramlen = roundup(nvramlen, cfe_erasesize);
 148
 149        buf = vmalloc(sizeof(struct bcm_tag));
 150        if (!buf)
 151                return -ENOMEM;
 152
 153        /* Get the tag */
 154        ret = bcm63xx_read_image_tag(master, "rootfs", cfelen, buf);
 155        if (!ret) {
 156                STR_NULL_TERMINATE(buf->flash_image_start);
 157                if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
 158                                rootfsaddr < BCM963XX_EXTENDED_SIZE) {
 159                        pr_err("invalid rootfs address: %*ph\n",
 160                                (int)sizeof(buf->flash_image_start),
 161                                buf->flash_image_start);
 162                        goto invalid_tag;
 163                }
 164
 165                STR_NULL_TERMINATE(buf->kernel_address);
 166                if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
 167                                kerneladdr < BCM963XX_EXTENDED_SIZE) {
 168                        pr_err("invalid kernel address: %*ph\n",
 169                                (int)sizeof(buf->kernel_address),
 170                                buf->kernel_address);
 171                        goto invalid_tag;
 172                }
 173
 174                STR_NULL_TERMINATE(buf->kernel_length);
 175                if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
 176                        pr_err("invalid kernel length: %*ph\n",
 177                                (int)sizeof(buf->kernel_length),
 178                                buf->kernel_length);
 179                        goto invalid_tag;
 180                }
 181
 182                STR_NULL_TERMINATE(buf->total_length);
 183                if (kstrtouint(buf->total_length, 10, &totallen)) {
 184                        pr_err("invalid total length: %*ph\n",
 185                                (int)sizeof(buf->total_length),
 186                                buf->total_length);
 187                        goto invalid_tag;
 188                }
 189
 190                kerneladdr = kerneladdr - BCM963XX_EXTENDED_SIZE;
 191                rootfsaddr = rootfsaddr - BCM963XX_EXTENDED_SIZE;
 192                spareaddr = roundup(totallen, master->erasesize) + cfelen;
 193
 194                if (rootfsaddr < kerneladdr) {
 195                        /* default Broadcom layout */
 196                        rootfslen = kerneladdr - rootfsaddr;
 197                        rootfs_first = true;
 198                } else {
 199                        /* OpenWrt layout */
 200                        rootfsaddr = kerneladdr + kernellen;
 201                        rootfslen = spareaddr - rootfsaddr;
 202                }
 203        } else if (ret > 0) {
 204invalid_tag:
 205                kernellen = 0;
 206                rootfslen = 0;
 207                rootfsaddr = 0;
 208                spareaddr = cfelen;
 209        } else {
 210                goto out;
 211        }
 212        sparelen = master->size - spareaddr - nvramlen;
 213
 214        /* Determine number of partitions */
 215        if (rootfslen > 0)
 216                nrparts++;
 217
 218        if (kernellen > 0)
 219                nrparts++;
 220
 221        parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 222        if (!parts) {
 223                ret = -ENOMEM;
 224                goto out;
 225        }
 226
 227        /* Start building partition list */
 228        parts[curpart].name = "CFE";
 229        parts[curpart].offset = 0;
 230        parts[curpart].size = cfelen;
 231        curpart++;
 232
 233        if (kernellen > 0) {
 234                int kernelpart = curpart;
 235
 236                if (rootfslen > 0 && rootfs_first)
 237                        kernelpart++;
 238                parts[kernelpart].name = "kernel";
 239                parts[kernelpart].offset = kerneladdr;
 240                parts[kernelpart].size = kernellen;
 241                curpart++;
 242        }
 243
 244        if (rootfslen > 0) {
 245                int rootfspart = curpart;
 246
 247                if (kernellen > 0 && rootfs_first)
 248                        rootfspart--;
 249                parts[rootfspart].name = "rootfs";
 250                parts[rootfspart].offset = rootfsaddr;
 251                parts[rootfspart].size = rootfslen;
 252                if (sparelen > 0  && !rootfs_first)
 253                        parts[rootfspart].size += sparelen;
 254                curpart++;
 255        }
 256
 257        parts[curpart].name = "nvram";
 258        parts[curpart].offset = master->size - nvramlen;
 259        parts[curpart].size = nvramlen;
 260        curpart++;
 261
 262        /* Global partition "linux" to make easy firmware upgrade */
 263        parts[curpart].name = "linux";
 264        parts[curpart].offset = cfelen;
 265        parts[curpart].size = master->size - cfelen - nvramlen;
 266
 267        for (i = 0; i < nrparts; i++)
 268                pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 269                        parts[i].name, parts[i].offset, parts[i].size);
 270
 271        pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 272                sparelen);
 273
 274        *pparts = parts;
 275        ret = 0;
 276
 277out:
 278        vfree(buf);
 279
 280        if (ret)
 281                return ret;
 282
 283        return nrparts;
 284}
 285
 286static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
 287                                        const struct mtd_partition **pparts,
 288                                        struct mtd_part_parser_data *data)
 289{
 290        struct bcm963xx_nvram *nvram = NULL;
 291        int ret;
 292
 293        if (bcm63xx_detect_cfe(master))
 294                return -EINVAL;
 295
 296        nvram = vzalloc(sizeof(*nvram));
 297        if (!nvram)
 298                return -ENOMEM;
 299
 300        ret = bcm63xx_read_nvram(master, nvram);
 301        if (ret)
 302                goto out;
 303
 304        if (!mtd_type_is_nand(master))
 305                ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
 306        else
 307                ret = -EINVAL;
 308
 309out:
 310        vfree(nvram);
 311        return ret;
 312};
 313
 314static struct mtd_part_parser bcm63xx_cfe_parser = {
 315        .parse_fn = bcm63xx_parse_cfe_partitions,
 316        .name = "bcm63xxpart",
 317};
 318module_mtd_part_parser(bcm63xx_cfe_parser);
 319
 320MODULE_LICENSE("GPL");
 321MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 322MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 323MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 324MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 325MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
 326