arch/common/boot/grub2/disk/host.c

   1 /* host.c - Dummy disk driver to provide access to the hosts filesystem  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2007  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* When using the disk, make a reference to this module.  Otherwise
  21    the user will end up with a useless module :-).  */
  22
  23 #include <grub/dl.h>
  24 #include <grub/disk.h>
  25 #include <grub/misc.h>
  26
  27 int grub_disk_host_i_want_a_reference;
  28
  29 static int
  30 grub_host_iterate (int (*hook) (const char *name))
  31 {
  32   if (hook ("host"))
  33     return 1;
  34   return 0;
  35 }
  36
  37 static grub_err_t
  38 grub_host_open (const char *name, grub_disk_t disk)
  39 {
  40   if (grub_strcmp (name, "host"))
  41       return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a host disk");
  42
  43   disk->total_sectors = 0;
  44   disk->id = (unsigned long) "host";
  45
  46   disk->has_partitions = 0;
  47   disk->data = 0;
  48
  49   return GRUB_ERR_NONE;
  50 }
  51
  52 static void
  53 grub_host_close (grub_disk_t disk __attribute((unused)))
  54 {
  55 }
  56
  57 static grub_err_t
  58 grub_host_read (grub_disk_t disk __attribute((unused)),
  59                 grub_disk_addr_t sector __attribute((unused)),
  60                 grub_size_t size __attribute((unused)),
  61                 char *buf __attribute((unused)))
  62 {
  63   return GRUB_ERR_OUT_OF_RANGE;
  64 }
  65
  66 static grub_err_t
  67 grub_host_write (grub_disk_t disk __attribute ((unused)),
  68                      grub_disk_addr_t sector __attribute ((unused)),
  69                      grub_size_t size __attribute ((unused)),
  70                      const char *buf __attribute ((unused)))
  71 {
  72   return GRUB_ERR_OUT_OF_RANGE;
  73 }
  74
  75 static struct grub_disk_dev grub_host_dev =
  76   {
  77     /* The only important line in this file :-) */
  78     .name = "host",
  79     .id = GRUB_DISK_DEVICE_HOST_ID,
  80     .iterate = grub_host_iterate,
  81     .open = grub_host_open,
  82     .close = grub_host_close,
  83     .read = grub_host_read,
  84     .write = grub_host_write,
  85     .next = 0
  86   };
  87
  88 GRUB_MOD_INIT(host)
  89 {
  90   (void) mod;                   /* To stop warning. */
  91   grub_disk_dev_register (&grub_host_dev);
  92 }
  93
  94 GRUB_MOD_FINI(host)
  95 {
  96   grub_disk_dev_unregister (&grub_host_dev);
  97 }