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 © 2011-2012  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
  45static 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
  69static 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        bool rootfs_first = false;
  86
  87        if (bcm63xx_detect_cfe(master))
  88                return -EINVAL;
  89
  90        cfelen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_CFE_SIZE);
  91        nvramlen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_NVRAM_SIZE);
  92
  93        /* Allocate memory for buffer */
  94        buf = vmalloc(sizeof(struct bcm_tag));
  95        if (!buf)
  96                return -ENOMEM;
  97
  98        /* Get the tag */
  99        ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
 100                       (void *)buf);
 101
 102        if (retlen != sizeof(struct bcm_tag)) {
 103                vfree(buf);
 104                return -EIO;
 105        }
 106
 107        computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
 108                                offsetof(struct bcm_tag, header_crc));
 109        if (computed_crc == buf->header_crc) {
 110                char *boardid = &(buf->board_id[0]);
 111                char *tagversion = &(buf->tag_version[0]);
 112
 113                sscanf(buf->flash_image_start, "%u", &rootfsaddr);
 114                sscanf(buf->kernel_address, "%u", &kerneladdr);
 115                sscanf(buf->kernel_length, "%u", &kernellen);
 116                sscanf(buf->total_length, "%u", &totallen);
 117
 118                pr_info("CFE boot tag found with version %s and board type %s\n",
 119                        tagversion, boardid);
 120
 121                kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
 122                rootfsaddr = rootfsaddr - BCM63XX_EXTENDED_SIZE;
 123                spareaddr = roundup(totallen, master->erasesize) + cfelen;
 124                sparelen = master->size - spareaddr - nvramlen;
 125
 126                if (rootfsaddr < kerneladdr) {
 127                        /* default Broadcom layout */
 128                        rootfslen = kerneladdr - rootfsaddr;
 129                        rootfs_first = true;
 130                } else {
 131                        /* OpenWrt layout */
 132                        rootfsaddr = kerneladdr + kernellen;
 133                        rootfslen = spareaddr - rootfsaddr;
 134                }
 135        } else {
 136                pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
 137                        buf->header_crc, computed_crc);
 138                kernellen = 0;
 139                rootfslen = 0;
 140                rootfsaddr = 0;
 141                spareaddr = cfelen;
 142                sparelen = master->size - cfelen - nvramlen;
 143        }
 144
 145        /* Determine number of partitions */
 146        namelen = 8;
 147        if (rootfslen > 0) {
 148                nrparts++;
 149                namelen += 6;
 150        }
 151        if (kernellen > 0) {
 152                nrparts++;
 153                namelen += 6;
 154        }
 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
 197        /* Global partition "linux" to make easy firmware upgrade */
 198        curpart++;
 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 %lx and length %lx\n", i,
 205                        parts[i].name, (long unsigned int)(parts[i].offset),
 206                        (long unsigned int)(parts[i].size));
 207
 208        pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 209                sparelen);
 210
 211        *pparts = parts;
 212        vfree(buf);
 213
 214        return nrparts;
 215};
 216
 217static struct mtd_part_parser bcm63xx_cfe_parser = {
 218        .owner = THIS_MODULE,
 219        .parse_fn = bcm63xx_parse_cfe_partitions,
 220        .name = "bcm63xxpart",
 221};
 222
 223static int __init bcm63xx_cfe_parser_init(void)
 224{
 225        return register_mtd_parser(&bcm63xx_cfe_parser);
 226}
 227
 228static void __exit bcm63xx_cfe_parser_exit(void)
 229{
 230        deregister_mtd_parser(&bcm63xx_cfe_parser);
 231}
 232
 233module_init(bcm63xx_cfe_parser_init);
 234module_exit(bcm63xx_cfe_parser_exit);
 235
 236MODULE_LICENSE("GPL");
 237MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 238MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 239MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 240MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 241MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
 242
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