grub/disk/fs_file.c
proski e14cd81437 2009-06-18 Pavel Roskin <proski@gnu.org>
* conf/common.rmk: Add fs_file.mod.
	* disk/fs_file.c: New file.
	* include/grub/disk.h (enum grub_disk_dev_id): Add
	GRUB_DISK_DEVICE_FILE_ID.
2009-06-18 20:00:34 +00:00

136 lines
3.3 KiB
C

/* fs_file.c - Access partition by a file it contains. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/file.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/partition.h>
static grub_device_t
search_fs_file (const char *key, unsigned long *count)
{
char *filename = NULL;
grub_device_t ret = NULL;
*count = 0;
auto int iterate_device (const char *name);
int iterate_device (const char *name)
{
int len;
grub_file_t file;
(*count)++;
len = grub_strlen (name) + 2 + grub_strlen (key) + 1;
filename = grub_realloc (filename, len);
if (! filename)
return 1;
grub_sprintf (filename, "(%s)%s", name, key);
file = grub_file_open (filename);
if (file)
{
grub_file_close (file);
ret = grub_device_open (name);
return 1;
}
grub_errno = GRUB_ERR_NONE;
return 0;
}
grub_device_iterate (iterate_device);
grub_free (filename);
return ret;
}
static grub_err_t
grub_fs_file_open (const char *name, grub_disk_t disk)
{
grub_device_t dev;
if (grub_strncmp (name, "FILE=", sizeof ("FILE=") - 1))
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a FILE virtual volume");
dev = search_fs_file (name + sizeof ("FILE=") - 1, &disk->id);
if (! dev)
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no matching file found");
disk->total_sectors = dev->disk->total_sectors;
disk->has_partitions = 0;
if (dev->disk->partition)
{
disk->partition = grub_malloc (sizeof (*disk->partition));
if (disk->partition)
grub_memcpy (disk->partition, dev->disk->partition,
sizeof (*disk->partition));
}
else
disk->partition = NULL;
disk->data = dev;
return GRUB_ERR_NONE;
}
static void
grub_fs_file_close (grub_disk_t disk)
{
grub_device_t parent = disk->data;
grub_device_close (parent);
}
static grub_err_t
grub_fs_file_read (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t size, char *buf)
{
grub_device_t parent = disk->data;
return parent->disk->dev->read (parent->disk, sector, size, buf);
}
static grub_err_t
grub_fs_file_write (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t size, const char *buf)
{
grub_device_t parent = disk->data;
return parent->disk->dev->write (parent->disk, sector, size, buf);
}
static struct grub_disk_dev grub_fs_file_dev = {
.name = "fs_file",
.id = GRUB_DISK_DEVICE_FILE_ID,
.open = grub_fs_file_open,
.close = grub_fs_file_close,
.read = grub_fs_file_read,
.write = grub_fs_file_write,
.next = 0
};
GRUB_MOD_INIT (fs_file)
{
grub_disk_dev_register (&grub_fs_file_dev);
}
GRUB_MOD_FINI (fs_file)
{
grub_disk_dev_unregister (&grub_fs_file_dev);
}