145 lines
3.7 KiB
C
145 lines
3.7 KiB
C
/* acorn.c - Read Linux/ADFS partition tables. */
|
||
/*
|
||
* GRUB -- GRand Unified Bootloader
|
||
* Copyright (C) 2005,2007 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/misc.h>
|
||
#include <grub/mm.h>
|
||
#include <grub/partition.h>
|
||
#include <grub/acorn_filecore.h>
|
||
|
||
#define LINUX_NATIVE_MAGIC grub_cpu_to_le32 (0xdeafa1de)
|
||
#define LINUX_SWAP_MAGIC grub_cpu_to_le32 (0xdeafab1e)
|
||
#define LINUX_MAP_ENTRIES (512 / 12)
|
||
|
||
#define NONADFS_PARTITION_TYPE_LINUX 9
|
||
#define NONADFS_PARTITION_TYPE_MASK 15
|
||
|
||
struct grub_acorn_boot_block
|
||
{
|
||
grub_uint8_t misc[0x1C0];
|
||
struct grub_filecore_disc_record disc_record;
|
||
grub_uint8_t flags;
|
||
grub_uint16_t start_cylinder;
|
||
grub_uint8_t checksum;
|
||
} __attribute__ ((packed, aligned));
|
||
|
||
struct linux_part
|
||
{
|
||
grub_uint32_t magic;
|
||
grub_uint32_t start;
|
||
grub_uint32_t size;
|
||
};
|
||
|
||
static struct grub_partition_map grub_acorn_partition_map;
|
||
|
||
static grub_err_t
|
||
acorn_partition_map_find (grub_disk_t disk, struct linux_part *m,
|
||
grub_disk_addr_t *sector)
|
||
{
|
||
struct grub_acorn_boot_block boot;
|
||
grub_err_t err;
|
||
unsigned int checksum = 0;
|
||
unsigned int heads;
|
||
unsigned int sectors_per_cylinder;
|
||
int i;
|
||
|
||
err = grub_disk_read (disk, 0xC00 / GRUB_DISK_SECTOR_SIZE, 0,
|
||
sizeof (struct grub_acorn_boot_block),
|
||
&boot);
|
||
if (err)
|
||
return err;
|
||
|
||
if ((boot.flags & NONADFS_PARTITION_TYPE_MASK) != NONADFS_PARTITION_TYPE_LINUX)
|
||
goto fail;
|
||
|
||
for (i = 0; i != 0x1ff; ++i)
|
||
checksum = (checksum & 0xff) + (checksum >> 8) + boot.misc[i];
|
||
|
||
if ((grub_uint8_t) checksum != boot.checksum)
|
||
goto fail;
|
||
|
||
heads = (boot.disc_record.heads
|
||
+ ((boot.disc_record.lowsector >> 6) & 1));
|
||
sectors_per_cylinder = boot.disc_record.secspertrack * heads;
|
||
*sector = grub_le_to_cpu16 (boot.start_cylinder) * sectors_per_cylinder;
|
||
|
||
return grub_disk_read (disk, *sector, 0,
|
||
sizeof (struct linux_part) * LINUX_MAP_ENTRIES,
|
||
m);
|
||
|
||
fail:
|
||
return grub_error (GRUB_ERR_BAD_PART_TABLE,
|
||
"Linux/ADFS partition map not found");
|
||
|
||
}
|
||
|
||
|
||
static grub_err_t
|
||
acorn_partition_map_iterate (grub_disk_t disk,
|
||
int (*hook) (grub_disk_t disk,
|
||
const grub_partition_t partition))
|
||
{
|
||
struct grub_partition part;
|
||
struct linux_part map[LINUX_MAP_ENTRIES];
|
||
int i;
|
||
grub_disk_addr_t sector = 0;
|
||
grub_err_t err;
|
||
|
||
err = acorn_partition_map_find (disk, map, §or);
|
||
if (err)
|
||
return err;
|
||
|
||
part.partmap = &grub_acorn_partition_map;
|
||
|
||
for (i = 0; i != LINUX_MAP_ENTRIES; ++i)
|
||
{
|
||
if (map[i].magic != LINUX_NATIVE_MAGIC
|
||
&& map[i].magic != LINUX_SWAP_MAGIC)
|
||
return GRUB_ERR_NONE;
|
||
|
||
part.start = sector + map[i].start;
|
||
part.len = map[i].size;
|
||
part.offset = 6;
|
||
part.number = part.index = i;
|
||
|
||
if (hook (disk, &part))
|
||
return grub_errno;
|
||
}
|
||
|
||
return GRUB_ERR_NONE;
|
||
}
|
||
|
||
|
||
|
||
/* Partition map type. */
|
||
static struct grub_partition_map grub_acorn_partition_map =
|
||
{
|
||
.name = "acorn",
|
||
.iterate = acorn_partition_map_iterate,
|
||
};
|
||
|
||
GRUB_MOD_INIT(acorn_partition_map)
|
||
{
|
||
grub_partition_map_register (&grub_acorn_partition_map);
|
||
}
|
||
|
||
GRUB_MOD_FINI(acorn_partition_map)
|
||
{
|
||
grub_partition_map_unregister (&grub_acorn_partition_map);
|
||
}
|