target/linux/ar71xx/files/drivers/mtd/tltpart.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/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/magic.h>
  15
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/mtd/partitions.h>
  18
  19 #define TLT_NUM_PARTS   7
  20 #define TLT_HEADER_V1   0x01000000
  21 #define MD5SUM_LEN              16
  22
  23 #define TLT_UBOOT_LEN   0x20000
  24 #define TLT_CONFIG_LEN  0x10000
  25 #define TLT_ART_LEN             0x10000
  26 #define EVENTLOG_LEN            0x90000
  27
  28 struct tlt_fw_header {
  29         uint32_t        version;        /* header version */
  30         char            vendor_name[24];
  31         char            fw_version[36];
  32         uint32_t        hw_id;          /* hardware id */
  33         uint32_t        hw_rev;         /* hardware revision */
  34         uint32_t        unk1;
  35         uint8_t         md5sum1[MD5SUM_LEN];
  36         uint32_t        unk2;
  37         uint8_t         md5sum2[MD5SUM_LEN];
  38         uint32_t        unk3;
  39         uint32_t        kernel_la;      /* kernel load address */
  40         uint32_t        kernel_ep;      /* kernel entry point */
  41         uint32_t        fw_length;      /* total length of the firmware */
  42         uint32_t        kernel_ofs;     /* kernel data offset */
  43         uint32_t        kernel_len;     /* kernel data length */
  44         uint32_t        rootfs_ofs;     /* rootfs data offset */
  45         uint32_t        rootfs_len;     /* rootfs data length */
  46         uint32_t        boot_ofs;       /* bootloader data offset */
  47         uint32_t        boot_len;       /* bootloader data length */
  48         uint8_t         pad[360];
  49 } __attribute__ ((packed));
  50
  51 static struct tlt_fw_header *
  52 tlt_read_header(struct mtd_info *mtd, size_t offset)
  53 {
  54         struct tlt_fw_header *header;
  55         size_t header_len;
  56         size_t retlen;
  57         int ret;
  58         u32 t;
  59
  60         header = vmalloc(sizeof(*header));
  61         if (!header)
  62                 goto err;
  63
  64         header_len = sizeof(struct tlt_fw_header);
  65         ret = mtd_read(mtd, offset, header_len, &retlen,
  66                        (unsigned char *) header);
  67         if (ret)
  68                 goto err_free_header;
  69
  70         if (retlen != header_len)
  71                 goto err_free_header;
  72
  73         /* sanity checks */
  74         t = be32_to_cpu(header->version);
  75         if (t != TLT_HEADER_V1)
  76                 goto err_free_header;
  77
  78         t = be32_to_cpu(header->kernel_ofs);
  79         if (t != header_len)
  80                 goto err_free_header;
  81
  82         return header;
  83
  84 err_free_header:
  85         vfree(header);
  86 err:
  87         return NULL;
  88 }
  89
  90 static int tlt_check_rootfs_magic(struct mtd_info *mtd, size_t offset)
  91 {
  92         u32 magic;
  93         size_t retlen;
  94         int ret;
  95
  96         ret = mtd_read(mtd, offset, sizeof(magic), &retlen,
  97                        (unsigned char *) &magic);
  98         if (ret)
  99                 return ret;
 100
 101         if (retlen != sizeof(magic))
 102                 return -EIO;
 103
 104         if (le32_to_cpu(magic) != SQUASHFS_MAGIC &&
 105             magic != 0x19852003)
 106                 return -EINVAL;
 107
 108         return 0;
 109 }
 110
 111 static int tlt_parse_partitions(struct mtd_info *master,
 112                                    struct mtd_partition **pparts,
 113                                    struct mtd_part_parser_data *data)
 114 {
 115         struct mtd_partition *parts;
 116         struct tlt_fw_header *header;
 117         int nr_parts;
 118         size_t kernel_offset;
 119         size_t rootfs_offset;
 120         size_t squashfs_offset;
 121         int ret;
 122
 123         nr_parts = TLT_NUM_PARTS;
 124         parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
 125         if (!parts) {
 126                 ret = -ENOMEM;
 127                 goto err;
 128         }
 129
 130         kernel_offset = TLT_UBOOT_LEN + TLT_CONFIG_LEN + TLT_ART_LEN;
 131
 132         header = tlt_read_header(master, kernel_offset);
 133         if (!header) {
 134                 pr_notice("%s: no TP-Link header found\n", master->name);
 135                 ret = -ENODEV;
 136                 goto err_free_parts;
 137         }
 138
 139         squashfs_offset = kernel_offset + sizeof(struct tlt_fw_header) +
 140                           be32_to_cpu(header->kernel_len);
 141
 142         ret = tlt_check_rootfs_magic(master, squashfs_offset);
 143         if (ret == 0)
 144                 rootfs_offset = squashfs_offset;
 145         else
 146                 rootfs_offset = kernel_offset + be32_to_cpu(header->rootfs_ofs);
 147
 148         vfree(header);
 149
 150         parts[0].name = "u-boot";
 151         parts[0].offset = 0;
 152         parts[0].size = TLT_UBOOT_LEN;
 153         parts[0].mask_flags = MTD_WRITEABLE;
 154
 155         parts[1].name = "config";
 156         parts[1].offset = TLT_UBOOT_LEN;
 157         parts[1].size = TLT_CONFIG_LEN;
 158
 159         parts[2].name = "art";
 160         parts[2].offset = TLT_UBOOT_LEN + TLT_CONFIG_LEN;
 161         parts[2].size = TLT_ART_LEN;
 162         parts[2].mask_flags = MTD_WRITEABLE;
 163
 164         parts[3].name = "kernel";
 165         parts[3].offset = kernel_offset;
 166         parts[3].size = rootfs_offset - kernel_offset;
 167
 168         parts[4].name = "rootfs";
 169         parts[4].offset = rootfs_offset;
 170         parts[4].size = master->size - rootfs_offset - EVENTLOG_LEN;
 171
 172         parts[5].name = "firmware";
 173         parts[5].offset = kernel_offset;
 174         parts[5].size = master->size - kernel_offset - EVENTLOG_LEN;
 175
 176         parts[6].name = "event-log";
 177         parts[6].offset = master->size - EVENTLOG_LEN;
 178         parts[6].size = EVENTLOG_LEN;
 179
 180         *pparts = parts;
 181         return nr_parts;
 182
 183 err_free_parts:
 184         kfree(parts);
 185 err:
 186         *pparts = NULL;
 187         return ret;
 188 }
 189
 190 static struct mtd_part_parser tlt_parser = {
 191         .owner          = THIS_MODULE,
 192         .parse_fn       = tlt_parse_partitions,
 193         .name           = "tlt",
 194 };
 195
 196 static int __init tlt_parser_init(void)
 197 {
 198         register_mtd_parser(&tlt_parser);
 199
 200         return 0;
 201 }
 202
 203 module_init(tlt_parser_init);
 204
 205 MODULE_LICENSE("GPL v2");
 206 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");