target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_fit.c

   1 /*
   2  * Copyright (c) 2015 The Linux Foundation
   3  * Copyright (C) 2014 Gabor Juhos <juhosg@openwrt.org>
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/partitions.h>
  21 #include <linux/types.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/slab.h>
  24 #include <linux/of_fdt.h>
  25
  26 #include "mtdsplit.h"
  27
  28 struct fdt_header {
  29         uint32_t magic;                  /* magic word FDT_MAGIC */
  30         uint32_t totalsize;              /* total size of DT block */
  31         uint32_t off_dt_struct;          /* offset to structure */
  32         uint32_t off_dt_strings;         /* offset to strings */
  33         uint32_t off_mem_rsvmap;         /* offset to memory reserve map */
  34         uint32_t version;                /* format version */
  35         uint32_t last_comp_version;      /* last compatible version */
  36
  37         /* version 2 fields below */
  38         uint32_t boot_cpuid_phys;        /* Which physical CPU id we're
  39                                             booting on */
  40         /* version 3 fields below */
  41         uint32_t size_dt_strings;        /* size of the strings block */
  42
  43         /* version 17 fields below */
  44         uint32_t size_dt_struct;         /* size of the structure block */
  45 };
  46
  47 static int
  48 mtdsplit_fit_parse(struct mtd_info *mtd,
  49                    const struct mtd_partition **pparts,
  50                    struct mtd_part_parser_data *data)
  51 {
  52         struct device_node *np = mtd_get_of_node(mtd);
  53         const char *cmdline_match = NULL;
  54         struct fdt_header hdr;
  55         size_t hdr_len, retlen;
  56         size_t offset;
  57         size_t fit_offset, fit_size;
  58         size_t rootfs_offset, rootfs_size;
  59         struct mtd_partition *parts;
  60         int ret;
  61
  62         of_property_read_string(np, "openwrt,cmdline-match", &cmdline_match);
  63         if (cmdline_match && !strstr(saved_command_line, cmdline_match))
  64                 return -ENODEV;
  65
  66         hdr_len = sizeof(struct fdt_header);
  67
  68         /* Parse the MTD device & search for the FIT image location */
  69         for(offset = 0; offset + hdr_len <= mtd->size; offset += mtd->erasesize) {
  70                 ret = mtd_read(mtd, offset, hdr_len, &retlen, (void*) &hdr);
  71                 if (ret) {
  72                         pr_err("read error in \"%s\" at offset 0x%llx\n",
  73                                mtd->name, (unsigned long long) offset);
  74                         return ret;
  75                 }
  76
  77                 if (retlen != hdr_len) {
  78                         pr_err("short read in \"%s\"\n", mtd->name);
  79                         return -EIO;
  80                 }
  81
  82                 /* Check the magic - see if this is a FIT image */
  83                 if (be32_to_cpu(hdr.magic) != OF_DT_HEADER) {
  84                         pr_debug("no valid FIT image found in \"%s\" at offset %llx\n",
  85                                  mtd->name, (unsigned long long) offset);
  86                         continue;
  87                 }
  88
  89                 /* We found a FIT image. Let's keep going */
  90                 break;
  91         }
  92
  93         fit_offset = offset;
  94         fit_size = be32_to_cpu(hdr.totalsize);
  95
  96         if (fit_size == 0) {
  97                 pr_err("FIT image in \"%s\" at offset %llx has null size\n",
  98                        mtd->name, (unsigned long long) fit_offset);
  99                 return -ENODEV;
 100         }
 101
 102         /* Search for the rootfs partition after the FIT image */
 103         ret = mtd_find_rootfs_from(mtd, fit_offset + fit_size, mtd->size,
 104                                    &rootfs_offset, NULL);
 105         if (ret) {
 106                 pr_info("no rootfs found after FIT image in \"%s\"\n",
 107                         mtd->name);
 108                 return ret;
 109         }
 110
 111         rootfs_size = mtd->size - rootfs_offset;
 112
 113         parts = kzalloc(2 * sizeof(*parts), GFP_KERNEL);
 114         if (!parts)
 115                 return -ENOMEM;
 116
 117         parts[0].name = KERNEL_PART_NAME;
 118         parts[0].offset = fit_offset;
 119         parts[0].size = mtd_rounddown_to_eb(fit_size, mtd) + mtd->erasesize;
 120
 121         parts[1].name = ROOTFS_PART_NAME;
 122         parts[1].offset = rootfs_offset;
 123         parts[1].size = rootfs_size;
 124
 125         *pparts = parts;
 126         return 2;
 127 }
 128
 129 static const struct of_device_id mtdsplit_fit_of_match_table[] = {
 130         { .compatible = "denx,fit" },
 131         {},
 132 };
 133
 134 static struct mtd_part_parser uimage_parser = {
 135         .owner = THIS_MODULE,
 136         .name = "fit-fw",
 137         .of_match_table = mtdsplit_fit_of_match_table,
 138         .parse_fn = mtdsplit_fit_parse,
 139         .type = MTD_PARSER_TYPE_FIRMWARE,
 140 };
 141
 142 /**************************************************
 143  * Init
 144  **************************************************/
 145
 146 static int __init mtdsplit_fit_init(void)
 147 {
 148         register_mtd_parser(&uimage_parser);
 149
 150         return 0;
 151 }
 152
 153 module_init(mtdsplit_fit_init);