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

   1 /*
   2  *  Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
   3  *  Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under the terms of the GNU General Public License version 2 as published
   7  *  by the Free Software Foundation.
   8  *
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/mtd/partitions.h>
  17 #include <linux/byteorder/generic.h>
  18
  19 #include "mtdsplit.h"
  20
  21 #define TPLINK_NR_PARTS         2
  22 #define TPLINK_MIN_ROOTFS_OFFS  0x80000 /* 512KiB */
  23
  24 #define MD5SUM_LEN  16
  25
  26 struct fw_v1 {
  27         char            vendor_name[24];
  28         char            fw_version[36];
  29         uint32_t        hw_id;          /* hardware id */
  30         uint32_t        hw_rev;         /* hardware revision */
  31         uint32_t        unk1;
  32         uint8_t         md5sum1[MD5SUM_LEN];
  33         uint32_t        unk2;
  34         uint8_t         md5sum2[MD5SUM_LEN];
  35         uint32_t        unk3;
  36         uint32_t        kernel_la;      /* kernel load address */
  37         uint32_t        kernel_ep;      /* kernel entry point */
  38         uint32_t        fw_length;      /* total length of the firmware */
  39         uint32_t        kernel_ofs;     /* kernel data offset */
  40         uint32_t        kernel_len;     /* kernel data length */
  41         uint32_t        rootfs_ofs;     /* rootfs data offset */
  42         uint32_t        rootfs_len;     /* rootfs data length */
  43         uint32_t        boot_ofs;       /* bootloader data offset */
  44         uint32_t        boot_len;       /* bootloader data length */
  45         uint8_t         pad[360];
  46 } __attribute__ ((packed));
  47
  48 struct fw_v2 {
  49         char            fw_version[48]; /* 0x04: fw version string */
  50         uint32_t        hw_id;          /* 0x34: hardware id */
  51         uint32_t        hw_rev;         /* 0x38: FIXME: hardware revision? */
  52         uint32_t        unk1;           /* 0x3c: 0x00000000 */
  53         uint8_t         md5sum1[MD5SUM_LEN]; /* 0x40 */
  54         uint32_t        unk2;           /* 0x50: 0x00000000 */
  55         uint8_t         md5sum2[MD5SUM_LEN]; /* 0x54 */
  56         uint32_t        unk3;           /* 0x64: 0xffffffff */
  57
  58         uint32_t        kernel_la;      /* 0x68: kernel load address */
  59         uint32_t        kernel_ep;      /* 0x6c: kernel entry point */
  60         uint32_t        fw_length;      /* 0x70: total length of the image */
  61         uint32_t        kernel_ofs;     /* 0x74: kernel data offset */
  62         uint32_t        kernel_len;     /* 0x78: kernel data length */
  63         uint32_t        rootfs_ofs;     /* 0x7c: rootfs data offset */
  64         uint32_t        rootfs_len;     /* 0x80: rootfs data length */
  65         uint32_t        boot_ofs;       /* 0x84: FIXME: seems to be unused */
  66         uint32_t        boot_len;       /* 0x88: FIXME: seems to be unused */
  67         uint16_t        unk4;           /* 0x8c: 0x55aa */
  68         uint8_t         sver_hi;        /* 0x8e */
  69         uint8_t         sver_lo;        /* 0x8f */
  70         uint8_t         unk5;           /* 0x90: magic: 0xa5 */
  71         uint8_t         ver_hi;         /* 0x91 */
  72         uint8_t         ver_mid;        /* 0x92 */
  73         uint8_t         ver_lo;         /* 0x93 */
  74         uint8_t         pad[364];
  75 } __attribute__ ((packed));
  76
  77 struct tplink_fw_header {
  78         uint32_t version;
  79         union {
  80                 struct fw_v1 v1;
  81                 struct fw_v2 v2;
  82         };
  83 };
  84
  85 static int mtdsplit_parse_tplink(struct mtd_info *master,
  86                                 struct mtd_partition **pparts,
  87                                 struct mtd_part_parser_data *data)
  88 {
  89         struct tplink_fw_header hdr;
  90         size_t hdr_len, retlen, kernel_size;
  91         size_t rootfs_offset;
  92         struct mtd_partition *parts;
  93         int err;
  94
  95         hdr_len = sizeof(hdr);
  96         err = mtd_read(master, 0, hdr_len, &retlen, (void *) &hdr);
  97         if (err)
  98                 return err;
  99
 100         if (retlen != hdr_len)
 101                 return -EIO;
 102
 103         switch (le32_to_cpu(hdr.version)) {
 104         case 1:
 105                 if (be32_to_cpu(hdr.v1.kernel_ofs) != sizeof(hdr))
 106                         return -EINVAL;
 107
 108                 kernel_size = sizeof(hdr) + be32_to_cpu(hdr.v1.kernel_len);
 109                 break;
 110         case 2:
 111         case 3:
 112                 if (be32_to_cpu(hdr.v2.kernel_ofs) != sizeof(hdr))
 113                         return -EINVAL;
 114
 115                 kernel_size = sizeof(hdr) + be32_to_cpu(hdr.v2.kernel_len);
 116                 break;
 117         default:
 118                 return -EINVAL;
 119         }
 120
 121         if (kernel_size > master->size)
 122                 return -EINVAL;
 123
 124         /* Find the rootfs after the kernel. */
 125         err = mtd_check_rootfs_magic(master, kernel_size, NULL);
 126         if (!err) {
 127                 rootfs_offset = kernel_size;
 128         } else {
 129                 /*
 130                  * The size in the header might cover the rootfs as well.
 131                  * Start the search from an arbitrary offset.
 132                  */
 133                 err = mtd_find_rootfs_from(master, TPLINK_MIN_ROOTFS_OFFS,
 134                                            master->size, &rootfs_offset, NULL);
 135                 if (err)
 136                         return err;
 137         }
 138
 139         parts = kzalloc(TPLINK_NR_PARTS * sizeof(*parts), GFP_KERNEL);
 140         if (!parts)
 141                 return -ENOMEM;
 142
 143         parts[0].name = KERNEL_PART_NAME;
 144         parts[0].offset = 0;
 145         parts[0].size = rootfs_offset;
 146
 147         parts[1].name = ROOTFS_PART_NAME;
 148         parts[1].offset = rootfs_offset;
 149         parts[1].size = master->size - rootfs_offset;
 150
 151         *pparts = parts;
 152         return TPLINK_NR_PARTS;
 153 }
 154
 155 static struct mtd_part_parser mtdsplit_tplink_parser = {
 156         .owner = THIS_MODULE,
 157         .name = "tplink-fw",
 158         .parse_fn = mtdsplit_parse_tplink,
 159         .type = MTD_PARSER_TYPE_FIRMWARE,
 160 };
 161
 162 static int __init mtdsplit_tplink_init(void)
 163 {
 164         register_mtd_parser(&mtdsplit_tplink_parser);
 165
 166         return 0;
 167 }
 168
 169 subsys_initcall(mtdsplit_tplink_init);