target/linux/ar71xx/files/drivers/mtd/tplinkpart.c

   1 /*
   2  * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12 #include <linux/vmalloc.h>
  13
  14 #include <linux/mtd/mtd.h>
  15 #include <linux/mtd/partitions.h>
  16
  17 #define TPLINK_NUM_PARTS        5
  18 #define TPLINK_HEADER_V1        0x01000000
  19 #define MD5SUM_LEN              16
  20
  21 #define TPLINK_ART_LEN          0x10000
  22 #define TPLINK_KERNEL_OFFS      0x20000
  23
  24 struct tplink_fw_header {
  25         uint32_t        version;        /* header version */
  26         char            vendor_name[24];
  27         char            fw_version[36];
  28         uint32_t        hw_id;          /* hardware id */
  29         uint32_t        hw_rev;         /* hardware revision */
  30         uint32_t        unk1;
  31         uint8_t         md5sum1[MD5SUM_LEN];
  32         uint32_t        unk2;
  33         uint8_t         md5sum2[MD5SUM_LEN];
  34         uint32_t        unk3;
  35         uint32_t        kernel_la;      /* kernel load address */
  36         uint32_t        kernel_ep;      /* kernel entry point */
  37         uint32_t        fw_length;      /* total length of the firmware */
  38         uint32_t        kernel_ofs;     /* kernel data offset */
  39         uint32_t        kernel_len;     /* kernel data length */
  40         uint32_t        rootfs_ofs;     /* rootfs data offset */
  41         uint32_t        rootfs_len;     /* rootfs data length */
  42         uint32_t        boot_ofs;       /* bootloader data offset */
  43         uint32_t        boot_len;       /* bootloader data length */
  44         uint8_t         pad[360];
  45 } __attribute__ ((packed));
  46
  47 static struct tplink_fw_header *
  48 tplink_read_header(struct mtd_info *mtd, size_t offset)
  49 {
  50         struct tplink_fw_header *header;
  51         size_t header_len;
  52         size_t retlen;
  53         int ret;
  54         u32 t;
  55
  56         header = vmalloc(sizeof(*header));
  57         if (!header)
  58                 goto err;
  59
  60         header_len = sizeof(struct tplink_fw_header);
  61         ret = mtd->read(mtd, offset, header_len, &retlen,
  62                         (unsigned char *) header);
  63         if (ret)
  64                 goto err_free_header;
  65
  66         if (retlen != header_len)
  67                 goto err_free_header;
  68
  69         /* sanity checks */
  70         t = be32_to_cpu(header->version);
  71         if (t != TPLINK_HEADER_V1)
  72                 goto err_free_header;
  73
  74         t = be32_to_cpu(header->kernel_ofs);
  75         if (t != header_len)
  76                 goto err_free_header;
  77
  78         return header;
  79
  80 err_free_header:
  81         vfree(header);
  82 err:
  83         return NULL;
  84 }
  85
  86 static int tplink_parse_partitions(struct mtd_info *master,
  87                                    struct mtd_partition **pparts,
  88                                    unsigned long origin)
  89 {
  90         struct mtd_partition *parts;
  91         struct tplink_fw_header *header;
  92         int nr_parts;
  93         size_t offset;
  94         size_t art_offset;
  95         size_t rootfs_offset;
  96         int ret;
  97
  98         nr_parts = TPLINK_NUM_PARTS;
  99         parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
 100         if (!parts) {
 101                 ret = -ENOMEM;
 102                 goto err;
 103         }
 104
 105         offset = TPLINK_KERNEL_OFFS;
 106
 107         header = tplink_read_header(master, offset);
 108         if (!header) {
 109                 pr_notice("%s: no TP-Link header found\n", master->name);
 110                 ret = -ENODEV;
 111                 goto err_free_parts;
 112         }
 113
 114         rootfs_offset = offset + be32_to_cpu(header->rootfs_ofs);
 115         art_offset = master->size - TPLINK_ART_LEN;
 116
 117         parts[0].name = "u-boot";
 118         parts[0].offset = 0;
 119         parts[0].size = offset;
 120         parts[0].mask_flags = MTD_WRITEABLE;
 121
 122         parts[1].name = "kernel";
 123         parts[1].offset = offset;
 124         parts[1].size = rootfs_offset - offset;
 125
 126         parts[2].name = "rootfs";
 127         parts[2].offset = rootfs_offset;
 128         parts[2].size = art_offset - rootfs_offset;
 129
 130         parts[3].name = "art";
 131         parts[3].offset = art_offset;
 132         parts[3].size = TPLINK_ART_LEN;
 133         parts[3].mask_flags = MTD_WRITEABLE;
 134
 135         parts[4].name = "firmware";
 136         parts[4].offset = offset;
 137         parts[4].size = art_offset - offset;
 138
 139         vfree(header);
 140
 141         *pparts = parts;
 142         return nr_parts;
 143
 144 err_free_parts:
 145         kfree(parts);
 146 err:
 147         *pparts = NULL;
 148         return ret;
 149 }
 150
 151 static struct mtd_part_parser tplink_parser = {
 152         .owner          = THIS_MODULE,
 153         .parse_fn       = tplink_parse_partitions,
 154         .name           = "tp-link",
 155 };
 156
 157 static int __init tplink_parser_init(void)
 158 {
 159         return register_mtd_parser(&tplink_parser);
 160 }
 161
 162 module_init(tplink_parser_init);
 163
 164 MODULE_LICENSE("GPL v2");
 165 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");