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/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
  46static 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
  70static 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
 216static struct mtd_part_parser bcm63xx_cfe_parser = {
 217        .owner = THIS_MODULE,
 218        .parse_fn = bcm63xx_parse_cfe_partitions,
 219        .name = "bcm63xxpart",
 220};
 221
 222static int __init bcm63xx_cfe_parser_init(void)
 223{
 224        return register_mtd_parser(&bcm63xx_cfe_parser);
 225}
 226
 227static void __exit bcm63xx_cfe_parser_exit(void)
 228{
 229        deregister_mtd_parser(&bcm63xx_cfe_parser);
 230}
 231
 232module_init(bcm63xx_cfe_parser_init);
 233module_exit(bcm63xx_cfe_parser_exit);
 234
 235MODULE_LICENSE("GPL");
 236MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 237MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 238MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 239MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 240MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
 241
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