2005-01-21 Marco Gerards <metgerards@student.han.nl>
Add the loopback device, a device via which files can be accessed as devices. * conf/i386-pc.rmk (grub_emu_SOURCES): Add `disk/loopback.c'. (pkgdata_MODULES): Add loopback.mod. (loopback_mod_SOURCES): New variable. (loopback_mod_CFLAGS): Likewise. * conf/powerpc-ieee1275.rmk (grub_emu_SOURCES): Add `disk/loopback.c'. (pkgdata_MODULES): Add loopback.mod. (loopback_mod_SOURCES): New variable. (loopback_mod_CFLAGS): Likewise. * disk/loopback.c: new file. * include/grub/normal.h (grub_loop_init): New prototype. (grub_loop_fini): New prototype. * util/grub-emu.c (main): Initialize and de-initialize loopback support. * include/grub/disk.h (grub_disk_dev_id): Add `GRUB_DISK_DEVICE_LOOPBACK_ID'.
This commit is contained in:
marco_g
parent
6f1c18bd82
commit
67bbaf0f38
9 changed files with 546 additions and 105 deletions
272
disk/loopback.c
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272
disk/loopback.c
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/* loopback.c - command to add loopback devices. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2005 Free Software Foundation, Inc.
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*
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* GRUB is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <grub/normal.h>
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#include <grub/dl.h>
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#include <grub/arg.h>
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#include <grub/misc.h>
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#include <grub/file.h>
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#include <grub/disk.h>
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#include <grub/mm.h>
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struct grub_loopback
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{
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char *devname;
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char *filename;
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int has_partitions;
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struct grub_loopback *next;
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};
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static struct grub_loopback *loopback_list;
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static const struct grub_arg_option options[] =
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{
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{"delete", 'd', 0, "Delete the loopback device entry", 0, 0},
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{"partitions", 'p', 0, "Set that the drive has partitions to"
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" simulate a harddrive", 0, 0},
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{0, 0, 0, 0, 0, 0}
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};
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/* Delete the loopback device NAME. */
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static grub_err_t
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delete_loopback (const char *name)
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{
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struct grub_loopback *dev;
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struct grub_loopback **prev;
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/* Search for the device. */
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for (dev = loopback_list, prev = &loopback_list;
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dev; prev = &dev->next, dev = dev->next)
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if (!grub_strcmp (dev->devname, name))
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break;
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if (!dev)
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return grub_error (GRUB_ERR_BAD_DEVICE, "Device not found");
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/* Remove the device from the list. */
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*prev = dev->next;
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grub_free (dev->devname);
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grub_free (dev->filename);
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grub_free (dev);
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return 0;
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}
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/* The command to add and remove loopback devices. */
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static grub_err_t
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grub_cmd_loopback (struct grub_arg_list *state,
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int argc, char **args)
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{
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grub_file_t file;
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struct grub_loopback *newdev;
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if (argc < 1)
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return grub_error (GRUB_ERR_BAD_ARGUMENT, "device name required");
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/* Check if `-d' was used. */
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if (state[0].set)
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return delete_loopback (args[0]);
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if (argc < 2)
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return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name required");
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file = grub_file_open (args[1]);
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if (! file)
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return grub_errno;
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/* Close the file, the only reason for opening it is validation. */
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grub_file_close (file);
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/* First try to replace the old device. */
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for (newdev = loopback_list; newdev; newdev = newdev->next)
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if (!grub_strcmp (newdev->devname, args[0]))
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break;
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if (newdev)
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{
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char *newname = grub_strdup (args[1]);
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if (!newname)
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return grub_errno;
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grub_free (newdev->filename);
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newdev->filename = newname;
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/* Set has_partitions when `--partitions' was used. */
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newdev->has_partitions = state[1].set;
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return 0;
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}
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/* Unable to replace it, make a new entry. */
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newdev = grub_malloc (sizeof (struct grub_loopback));
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if (!newdev)
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return grub_errno;
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newdev->devname = grub_strdup (args[0]);
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if (!newdev->devname)
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{
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grub_free (newdev);
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return grub_errno;
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}
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newdev->filename = grub_strdup (args[1]);
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if (!newdev->devname)
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{
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grub_free (newdev->devname);
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grub_free (newdev);
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return grub_errno;
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}
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/* Set has_partitions when `--partitions' was used. */
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newdev->has_partitions = state[1].set;
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/* Add the new entry to the list. */
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newdev->next = loopback_list;
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loopback_list = newdev;
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return 0;
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}
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static int
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grub_loopback_iterate (int (*hook) (const char *name))
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{
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struct grub_loopback *d;
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for (d = loopback_list; d; d = d->next)
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{
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if (hook (d->devname))
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return 1;
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}
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return 0;
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}
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static grub_err_t
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grub_loopback_open (const char *name, grub_disk_t disk)
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{
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grub_file_t file;
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struct grub_loopback *dev;
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for (dev = loopback_list; dev; dev = dev->next)
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if (!grub_strcmp (dev->devname, name))
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break;
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if (! dev)
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return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Can't open device");
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file = grub_file_open (dev->filename);
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if (! file)
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return grub_errno;
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/* Use the filesize for the disk size, round up to a complete sector. */
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disk->total_sectors = ((file->size + GRUB_DISK_SECTOR_SIZE - 1)
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/ GRUB_DISK_SECTOR_SIZE);
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disk->id = (int) dev;
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disk->has_partitions = dev->has_partitions;
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disk->data = file;
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return 0;
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}
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static void
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grub_loopback_close (grub_disk_t disk)
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{
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grub_file_t file = (grub_file_t) disk->data;
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grub_file_close (file);
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}
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static grub_err_t
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grub_loopback_read (grub_disk_t disk, unsigned long sector,
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unsigned long size, char *buf)
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{
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grub_file_t file = (grub_file_t) disk->data;
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long pos;
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grub_file_seek (file, sector * GRUB_DISK_SECTOR_SIZE);
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grub_file_read (file, buf, size * GRUB_DISK_SECTOR_SIZE);
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if (grub_errno)
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return grub_errno;
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/* In case there is more data read than there is available, in case
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of files that are not a multiple of GRUB_DISK_SECTOR_SIZE, fill
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the rest with zeros. */
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pos = sector * GRUB_DISK_SECTOR_SIZE + size * GRUB_DISK_SECTOR_SIZE;
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if (pos > file->size)
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{
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unsigned long amount = pos - file->size;
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grub_memset (buf + pos - amount, amount, 0);
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}
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return 0;
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}
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static grub_err_t
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grub_loopback_write (grub_disk_t disk __attribute ((unused)),
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unsigned long sector __attribute ((unused)),
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unsigned long size __attribute ((unused)),
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const char *buf __attribute ((unused)))
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{
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return GRUB_ERR_NOT_IMPLEMENTED_YET;
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}
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static struct grub_disk_dev grub_loopback_dev =
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{
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.name = "loopback",
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.id = GRUB_DISK_DEVICE_LOOPBACK_ID,
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.iterate = grub_loopback_iterate,
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.open = grub_loopback_open,
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.close = grub_loopback_close,
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.read = grub_loopback_read,
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.write = grub_loopback_write,
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.next = 0
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};
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#ifdef GRUB_UTIL
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void
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grub_loop_init (void)
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{
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grub_register_command ("loopback", grub_cmd_loopback, GRUB_COMMAND_FLAG_BOTH,
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"loopback [OPTIONS] DEVICENAME FILE", "Makes a device of a file", options);
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grub_disk_dev_register (&grub_loopback_dev);
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}
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void
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grub_loop_fini (void)
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{
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grub_unregister_command ("loopback");
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grub_disk_dev_unregister (&grub_loopback_dev);
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}
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#else /* ! GRUB_UTIL */
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GRUB_MOD_INIT
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{
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(void)mod; /* To stop warning. */
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grub_register_command ("loopback", grub_cmd_loopback, GRUB_COMMAND_FLAG_BOTH,
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"loopback [OPTIONS] DEVICENAME FILE", "Makes a device of a file", options);
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grub_disk_dev_register (&grub_loopback_dev);
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}
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GRUB_MOD_FINI
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{
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grub_unregister_command ("loopback");
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grub_disk_dev_unregister (&grub_loopback_dev);
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}
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#endif /* ! GRUB_UTIL */
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