1
/* memdisk.c - Access embedded memory disk. */
3
* GRUB -- GRand Unified Bootloader
4
* Copyright (C) 2007,2008 Free Software Foundation, Inc.
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.
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.
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/>.
20
#include <grub/disk.h>
22
#include <grub/kernel.h>
23
#include <grub/misc.h>
25
#include <grub/types.h>
26
#include <grub/machine/kernel.h>
28
static char *memdisk_addr;
29
static grub_off_t memdisk_size = 0;
32
grub_memdisk_iterate (int (*hook) (const char *name))
34
return hook ("memdisk");
38
grub_memdisk_open (const char *name, grub_disk_t disk)
40
if (grub_strcmp (name, "memdisk"))
41
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a memdisk");
43
disk->total_sectors = memdisk_size / GRUB_DISK_SECTOR_SIZE;
44
disk->id = (unsigned long) "mdsk";
45
disk->has_partitions = 0;
51
grub_memdisk_close (grub_disk_t disk __attribute((unused)))
56
grub_memdisk_read (grub_disk_t disk __attribute((unused)), grub_disk_addr_t sector,
57
grub_size_t size, char *buf)
59
grub_memcpy (buf, memdisk_addr + (sector << GRUB_DISK_SECTOR_BITS), size << GRUB_DISK_SECTOR_BITS);
64
grub_memdisk_write (grub_disk_t disk __attribute((unused)), grub_disk_addr_t sector,
65
grub_size_t size, const char *buf)
67
grub_memcpy (memdisk_addr + (sector << GRUB_DISK_SECTOR_BITS), buf, size << GRUB_DISK_SECTOR_BITS);
71
static struct grub_disk_dev grub_memdisk_dev =
74
.id = GRUB_DISK_DEVICE_MEMDISK_ID,
75
.iterate = grub_memdisk_iterate,
76
.open = grub_memdisk_open,
77
.close = grub_memdisk_close,
78
.read = grub_memdisk_read,
79
.write = grub_memdisk_write,
83
GRUB_MOD_INIT(memdisk)
85
auto int hook (struct grub_module_header *);
86
int hook (struct grub_module_header *header)
88
if (header->type == OBJ_TYPE_MEMDISK)
90
char *memdisk_orig_addr;
91
memdisk_orig_addr = (char *) header + sizeof (struct grub_module_header);
93
grub_dprintf ("memdisk", "Found memdisk image at %p\n", memdisk_orig_addr);
95
memdisk_size = header->size - sizeof (struct grub_module_header);
96
memdisk_addr = grub_malloc (memdisk_size);
98
grub_dprintf ("memdisk", "Copying memdisk image to dynamic memory\n");
99
grub_memmove (memdisk_addr, memdisk_orig_addr, memdisk_size);
101
grub_disk_dev_register (&grub_memdisk_dev);
108
grub_module_iterate (hook);
111
GRUB_MOD_FINI(memdisk)
115
grub_free (memdisk_addr);
116
grub_disk_dev_unregister (&grub_memdisk_dev);