drivers/mtd/parsers/bcm63xxpart.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_nvram.h>
  14 #include <linux/bcm963xx_tag.h>
  15 #include <linux/crc32.h>
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/sizes.h>
  19 #include <linux/slab.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/partitions.h>
  23 #include <linux/of.h>
  24
  25 #define BCM963XX_CFE_BLOCK_SIZE         SZ_64K  /* always at least 64KiB */
  26
  27 #define BCM963XX_CFE_MAGIC_OFFSET       0x4e0
  28 #define BCM963XX_CFE_VERSION_OFFSET     0x570
  29 #define BCM963XX_NVRAM_OFFSET           0x580
  30
  31 /* Ensure strings read from flash structs are null terminated */
  32 #define STR_NULL_TERMINATE(x) \
  33         do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
  34
  35 static int bcm63xx_detect_cfe(struct mtd_info *master)
  36 {
  37         char buf[9];
  38         int ret;
  39         size_t retlen;
  40
  41         ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
  42                        (void *)buf);
  43         buf[retlen] = 0;
  44
  45         if (ret)
  46                 return ret;
  47
  48         if (strncmp("cfe-v", buf, 5) == 0)
  49                 return 0;
  50
  51         /* very old CFE's do not have the cfe-v string, so check for magic */
  52         ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
  53                        (void *)buf);
  54         buf[retlen] = 0;
  55
  56         return strncmp("CFE1CFE1", buf, 8);
  57 }
  58
  59 static int bcm63xx_read_nvram(struct mtd_info *master,
  60         struct bcm963xx_nvram *nvram)
  61 {
  62         u32 actual_crc, expected_crc;
  63         size_t retlen;
  64         int ret;
  65
  66         /* extract nvram data */
  67         ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
  68                         &retlen, (void *)nvram);
  69         if (ret)
  70                 return ret;
  71
  72         ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
  73         if (ret)
  74                 pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  75                         expected_crc, actual_crc);
  76
  77         if (!nvram->psi_size)
  78                 nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
  79
  80         return 0;
  81 }
  82
  83 static const char * const bcm63xx_cfe_part_types[] = {
  84         "bcm963xx-imagetag",
  85         NULL,
  86 };
  87
  88 static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
  89         const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
  90 {
  91         struct mtd_partition *parts;
  92         int nrparts = 3, curpart = 0;
  93         unsigned int cfelen, nvramlen;
  94         unsigned int cfe_erasesize;
  95         int i;
  96
  97         cfe_erasesize = max_t(uint32_t, master->erasesize,
  98                               BCM963XX_CFE_BLOCK_SIZE);
  99
 100         cfelen = cfe_erasesize;
 101         nvramlen = nvram->psi_size * SZ_1K;
 102         nvramlen = roundup(nvramlen, cfe_erasesize);
 103
 104         parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
 105         if (!parts)
 106                 return -ENOMEM;
 107
 108         /* Start building partition list */
 109         parts[curpart].name = "CFE";
 110         parts[curpart].offset = 0;
 111         parts[curpart].size = cfelen;
 112         curpart++;
 113
 114         parts[curpart].name = "nvram";
 115         parts[curpart].offset = master->size - nvramlen;
 116         parts[curpart].size = nvramlen;
 117         curpart++;
 118
 119         /* Global partition "linux" to make easy firmware upgrade */
 120         parts[curpart].name = "linux";
 121         parts[curpart].offset = cfelen;
 122         parts[curpart].size = master->size - cfelen - nvramlen;
 123         parts[curpart].types = bcm63xx_cfe_part_types;
 124
 125         for (i = 0; i < nrparts; i++)
 126                 pr_info("Partition %d is %s offset %llx and length %llx\n", i,
 127                         parts[i].name, parts[i].offset, parts[i].size);
 128
 129         *pparts = parts;
 130
 131         return nrparts;
 132 }
 133
 134 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
 135                                         const struct mtd_partition **pparts,
 136                                         struct mtd_part_parser_data *data)
 137 {
 138         struct bcm963xx_nvram *nvram = NULL;
 139         int ret;
 140
 141         if (bcm63xx_detect_cfe(master))
 142                 return -EINVAL;
 143
 144         nvram = vzalloc(sizeof(*nvram));
 145         if (!nvram)
 146                 return -ENOMEM;
 147
 148         ret = bcm63xx_read_nvram(master, nvram);
 149         if (ret)
 150                 goto out;
 151
 152         if (!mtd_type_is_nand(master))
 153                 ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
 154         else
 155                 ret = -EINVAL;
 156
 157 out:
 158         vfree(nvram);
 159         return ret;
 160 };
 161
 162 static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
 163         { .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
 164         {},
 165 };
 166 MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);
 167
 168 static struct mtd_part_parser bcm63xx_cfe_parser = {
 169         .parse_fn = bcm63xx_parse_cfe_partitions,
 170         .name = "bcm63xxpart",
 171         .of_match_table = parse_bcm63xx_cfe_match_table,
 172 };
 173 module_mtd_part_parser(bcm63xx_cfe_parser);
 174
 175 MODULE_LICENSE("GPL");
 176 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
 177 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 178 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
 179 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
 180 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");