linux/drivers/mtd/parsers/parser_imagetag.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * BCM63XX CFE image tag parser
   4 *
   5 * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
   6 *                        Mike Albon <malbon@openwrt.org>
   7 * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
   8 * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/bcm963xx_tag.h>
  14#include <linux/crc32.h>
  15#include <linux/module.h>
  16#include <linux/kernel.h>
  17#include <linux/sizes.h>
  18#include <linux/slab.h>
  19#include <linux/vmalloc.h>
  20#include <linux/mtd/mtd.h>
  21#include <linux/mtd/partitions.h>
  22#include <linux/of.h>
  23
  24/* Ensure strings read from flash structs are null terminated */
  25#define STR_NULL_TERMINATE(x) \
  26        do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
  27
  28static int bcm963xx_read_imagetag(struct mtd_info *master, const char *name,
  29        loff_t tag_offset, struct bcm_tag *buf)
  30{
  31        int ret;
  32        size_t retlen;
  33        u32 computed_crc;
  34
  35        ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
  36        if (ret)
  37                return ret;
  38
  39        if (retlen != sizeof(*buf))
  40                return -EIO;
  41
  42        computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
  43                                offsetof(struct bcm_tag, header_crc));
  44        if (computed_crc == buf->header_crc) {
  45                STR_NULL_TERMINATE(buf->board_id);
  46                STR_NULL_TERMINATE(buf->tag_version);
  47
  48                pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
  49                        name, tag_offset, buf->tag_version, buf->board_id);
  50
  51                return 0;
  52        }
  53
  54        pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
  55                name, tag_offset, buf->header_crc, computed_crc);
  56        return -EINVAL;
  57}
  58
  59static int bcm963xx_parse_imagetag_partitions(struct mtd_info *master,
  60                                        const struct mtd_partition **pparts,
  61                                        struct mtd_part_parser_data *data)
  62{
  63        /* CFE, NVRAM and global Linux are always present */
  64        int nrparts = 0, curpart = 0;
  65        struct bcm_tag *buf = NULL;
  66        struct mtd_partition *parts;
  67        int ret;
  68        unsigned int rootfsaddr, kerneladdr, spareaddr, offset;
  69        unsigned int rootfslen, kernellen, sparelen, totallen;
  70        int i;
  71        bool rootfs_first = false;
  72
  73        buf = vmalloc(sizeof(struct bcm_tag));
  74        if (!buf)
  75                return -ENOMEM;
  76
  77        /* Get the tag */
  78        ret = bcm963xx_read_imagetag(master, "rootfs", 0, buf);
  79        if (!ret) {
  80                STR_NULL_TERMINATE(buf->flash_image_start);
  81                if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
  82                                rootfsaddr < BCM963XX_EXTENDED_SIZE) {
  83                        pr_err("invalid rootfs address: %*ph\n",
  84                                (int)sizeof(buf->flash_image_start),
  85                                buf->flash_image_start);
  86                        goto out;
  87                }
  88
  89                STR_NULL_TERMINATE(buf->kernel_address);
  90                if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
  91                                kerneladdr < BCM963XX_EXTENDED_SIZE) {
  92                        pr_err("invalid kernel address: %*ph\n",
  93                                (int)sizeof(buf->kernel_address),
  94                                buf->kernel_address);
  95                        goto out;
  96                }
  97
  98                STR_NULL_TERMINATE(buf->kernel_length);
  99                if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
 100                        pr_err("invalid kernel length: %*ph\n",
 101                                (int)sizeof(buf->kernel_length),
 102                                buf->kernel_length);
 103                        goto out;
 104                }
 105
 106                STR_NULL_TERMINATE(buf->total_length);
 107                if (kstrtouint(buf->total_length, 10, &totallen)) {
 108                        pr_err("invalid total length: %*ph\n",
 109                                (int)sizeof(buf->total_length),
 110                                buf->total_length);
 111                        goto out;
 112                }
 113
 114                /*
 115                 * Addresses are flash absolute, so convert to partition
 116                 * relative addresses. Assume either kernel or rootfs will
 117                 * directly follow the image tag.
 118                 */
 119                if (rootfsaddr < kerneladdr)
 120                        offset = rootfsaddr - sizeof(struct bcm_tag);
 121                else
 122                        offset = kerneladdr - sizeof(struct bcm_tag);
 123
 124                kerneladdr = kerneladdr - offset;
 125                rootfsaddr = rootfsaddr - offset;
 126                spareaddr = roundup(totallen, master->erasesize);
 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                goto out;
 139        }
 140        sparelen = master->size - spareaddr;
 141
 142        /* Determine number of partitions */
 143        if (rootfslen > 0)
 144                nrparts++;
 145
 146        if (kernellen > 0)
 147                nrparts++;
 148
 149        parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 150        if (!parts) {
 151                ret = -ENOMEM;
 152                goto out;
 153        }
 154
 155        /* Start building partition list */
 156        if (kernellen > 0) {
 157                int kernelpart = curpart;
 158
 159                if (rootfslen > 0 && rootfs_first)
 160                        kernelpart++;
 161                parts[kernelpart].name = "kernel";
 162                parts[kernelpart].offset = kerneladdr;
 163                parts[kernelpart].size = kernellen;
 164                curpart++;
 165        }
 166
 167        if (rootfslen > 0) {
 168                int rootfspart = curpart;
 169
 170                if (kernellen > 0 && rootfs_first)
 171                        rootfspart--;
 172                parts[rootfspart].name = "rootfs";
 173                parts[rootfspart].offset = rootfsaddr;
 174                parts[rootfspart].size = rootfslen;
 175                if (sparelen > 0  && !rootfs_first)
 176                        parts[rootfspart].size += sparelen;
 177                curpart++;
 178        }
 179
 180        for (i = 0; i < nrparts; i++)
 181                pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 182                        parts[i].name, parts[i].offset, parts[i].size);
 183
 184        pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 185                sparelen);
 186
 187        *pparts = parts;
 188        ret = 0;
 189
 190out:
 191        vfree(buf);
 192
 193        if (ret)
 194                return ret;
 195
 196        return nrparts;
 197}
 198
 199static const struct of_device_id parse_bcm963xx_imagetag_match_table[] = {
 200        { .compatible = "brcm,bcm963xx-imagetag" },
 201        {},
 202};
 203MODULE_DEVICE_TABLE(of, parse_bcm963xx_imagetag_match_table);
 204
 205static struct mtd_part_parser bcm963xx_imagetag_parser = {
 206        .parse_fn = bcm963xx_parse_imagetag_partitions,
 207        .name = "bcm963xx-imagetag",
 208        .of_match_table = parse_bcm963xx_imagetag_match_table,
 209};
 210module_mtd_part_parser(bcm963xx_imagetag_parser);
 211
 212MODULE_LICENSE("GPL");
 213MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 214MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 215MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 216MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com>");
 217MODULE_DESCRIPTION("MTD parser for BCM963XX CFE Image Tag partitions");
 218