drivers/mtd/parsers/parser_imagetag.c

   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
  28 static 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
  59 static 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                         ret = -EINVAL;
  87                         goto out;
  88                 }
  89
  90                 STR_NULL_TERMINATE(buf->kernel_address);
  91                 if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
  92                                 kerneladdr < BCM963XX_EXTENDED_SIZE) {
  93                         pr_err("invalid kernel address: %*ph\n",
  94                                 (int)sizeof(buf->kernel_address),
  95                                 buf->kernel_address);
  96                         ret = -EINVAL;
  97                         goto out;
  98                 }
  99
 100                 STR_NULL_TERMINATE(buf->kernel_length);
 101                 if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
 102                         pr_err("invalid kernel length: %*ph\n",
 103                                 (int)sizeof(buf->kernel_length),
 104                                 buf->kernel_length);
 105                         ret = -EINVAL;
 106                         goto out;
 107                 }
 108
 109                 STR_NULL_TERMINATE(buf->total_length);
 110                 if (kstrtouint(buf->total_length, 10, &totallen)) {
 111                         pr_err("invalid total length: %*ph\n",
 112                                 (int)sizeof(buf->total_length),
 113                                 buf->total_length);
 114                         ret = -EINVAL;
 115                         goto out;
 116                 }
 117
 118                 /*
 119                  * Addresses are flash absolute, so convert to partition
 120                  * relative addresses. Assume either kernel or rootfs will
 121                  * directly follow the image tag.
 122                  */
 123                 if (rootfsaddr < kerneladdr)
 124                         offset = rootfsaddr - sizeof(struct bcm_tag);
 125                 else
 126                         offset = kerneladdr - sizeof(struct bcm_tag);
 127
 128                 kerneladdr = kerneladdr - offset;
 129                 rootfsaddr = rootfsaddr - offset;
 130                 spareaddr = roundup(totallen, master->erasesize);
 131
 132                 if (rootfsaddr < kerneladdr) {
 133                         /* default Broadcom layout */
 134                         rootfslen = kerneladdr - rootfsaddr;
 135                         rootfs_first = true;
 136                 } else {
 137                         /* OpenWrt layout */
 138                         rootfsaddr = kerneladdr + kernellen;
 139                         rootfslen = spareaddr - rootfsaddr;
 140                 }
 141         } else {
 142                 goto out;
 143         }
 144         sparelen = master->size - spareaddr;
 145
 146         /* Determine number of partitions */
 147         if (rootfslen > 0)
 148                 nrparts++;
 149
 150         if (kernellen > 0)
 151                 nrparts++;
 152
 153         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 154         if (!parts) {
 155                 ret = -ENOMEM;
 156                 goto out;
 157         }
 158
 159         /* Start building partition list */
 160         if (kernellen > 0) {
 161                 int kernelpart = curpart;
 162
 163                 if (rootfslen > 0 && rootfs_first)
 164                         kernelpart++;
 165                 parts[kernelpart].name = "kernel";
 166                 parts[kernelpart].offset = kerneladdr;
 167                 parts[kernelpart].size = kernellen;
 168                 curpart++;
 169         }
 170
 171         if (rootfslen > 0) {
 172                 int rootfspart = curpart;
 173
 174                 if (kernellen > 0 && rootfs_first)
 175                         rootfspart--;
 176                 parts[rootfspart].name = "rootfs";
 177                 parts[rootfspart].offset = rootfsaddr;
 178                 parts[rootfspart].size = rootfslen;
 179                 if (sparelen > 0  && !rootfs_first)
 180                         parts[rootfspart].size += sparelen;
 181                 curpart++;
 182         }
 183
 184         for (i = 0; i < nrparts; i++)
 185                 pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 186                         parts[i].name, parts[i].offset, parts[i].size);
 187
 188         pr_info("Spare partition is offset %x and length %x\n", spareaddr,
 189                 sparelen);
 190
 191         *pparts = parts;
 192         ret = 0;
 193
 194 out:
 195         vfree(buf);
 196
 197         if (ret)
 198                 return ret;
 199
 200         return nrparts;
 201 }
 202
 203 static const struct of_device_id parse_bcm963xx_imagetag_match_table[] = {
 204         { .compatible = "brcm,bcm963xx-imagetag" },
 205         {},
 206 };
 207 MODULE_DEVICE_TABLE(of, parse_bcm963xx_imagetag_match_table);
 208
 209 static struct mtd_part_parser bcm963xx_imagetag_parser = {
 210         .parse_fn = bcm963xx_parse_imagetag_partitions,
 211         .name = "bcm963xx-imagetag",
 212         .of_match_table = parse_bcm963xx_imagetag_match_table,
 213 };
 214 module_mtd_part_parser(bcm963xx_imagetag_parser);
 215
 216 MODULE_LICENSE("GPL");
 217 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 218 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 219 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 220 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com>");
 221 MODULE_DESCRIPTION("MTD parser for BCM963XX CFE Image Tag partitions");