1 /* acorn.c - Read Linux/ADFS partition tables. */
3 * GRUB -- GRand Unified Bootloader
4 * Copyright (C) 2005,2007 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>
21 #include <grub/misc.h>
23 #include <grub/partition.h>
24 #include <grub/acorn_filecore.h>
26 #define LINUX_NATIVE_MAGIC grub_cpu_to_le32 (0xdeafa1de)
27 #define LINUX_SWAP_MAGIC grub_cpu_to_le32 (0xdeafab1e)
28 #define LINUX_MAP_ENTRIES (512 / 12)
30 #define NONADFS_PARTITION_TYPE_LINUX 9
31 #define NONADFS_PARTITION_TYPE_MASK 15
33 struct grub_acorn_boot_block
35 grub_uint8_t misc
[0x1C0];
36 struct grub_filecore_disc_record disc_record
;
38 grub_uint16_t start_cylinder
;
39 grub_uint8_t checksum
;
40 } __attribute__ ((packed
, aligned
));
49 static struct grub_partition_map grub_acorn_partition_map
;
52 acorn_partition_map_find (grub_disk_t disk
, struct linux_part
*m
,
53 grub_disk_addr_t
*sector
)
55 struct grub_acorn_boot_block boot
;
57 unsigned int checksum
= 0;
59 unsigned int sectors_per_cylinder
;
62 err
= grub_disk_read (disk
, 0xC00 / GRUB_DISK_SECTOR_SIZE
, 0,
63 sizeof (struct grub_acorn_boot_block
),
68 if ((boot
.flags
& NONADFS_PARTITION_TYPE_MASK
) != NONADFS_PARTITION_TYPE_LINUX
)
71 for (i
= 0; i
!= 0x1ff; ++i
)
72 checksum
= (checksum
& 0xff) + (checksum
>> 8) + boot
.misc
[i
];
74 if ((grub_uint8_t
) checksum
!= boot
.checksum
)
77 heads
= (boot
.disc_record
.heads
78 + ((boot
.disc_record
.lowsector
>> 6) & 1));
79 sectors_per_cylinder
= boot
.disc_record
.secspertrack
* heads
;
80 *sector
= grub_le_to_cpu16 (boot
.start_cylinder
) * sectors_per_cylinder
;
82 return grub_disk_read (disk
, *sector
, 0,
83 sizeof (struct linux_part
) * LINUX_MAP_ENTRIES
,
87 return grub_error (GRUB_ERR_BAD_PART_TABLE
,
88 "Linux/ADFS partition map not found.");
94 acorn_partition_map_iterate (grub_disk_t disk
,
95 int (*hook
) (grub_disk_t disk
,
96 const grub_partition_t partition
))
98 struct grub_partition part
;
99 struct linux_part map
[LINUX_MAP_ENTRIES
];
101 grub_disk_addr_t sector
= 0;
104 err
= acorn_partition_map_find (disk
, map
, §or
);
108 part
.partmap
= &grub_acorn_partition_map
;
111 for (i
= 0; i
!= LINUX_MAP_ENTRIES
; ++i
)
113 if (map
[i
].magic
!= LINUX_NATIVE_MAGIC
114 && map
[i
].magic
!= LINUX_SWAP_MAGIC
)
115 return GRUB_ERR_NONE
;
117 part
.start
= sector
+ map
[i
].start
;
118 part
.len
= map
[i
].size
;
122 if (hook (disk
, &part
))
126 return GRUB_ERR_NONE
;
131 /* Partition map type. */
132 static struct grub_partition_map grub_acorn_partition_map
=
134 .name
= "Linux/ADFS partition map",
135 .iterate
= acorn_partition_map_iterate
,
138 GRUB_MOD_INIT(acorn_partition_map
)
140 grub_partition_map_register (&grub_acorn_partition_map
);
143 GRUB_MOD_FINI(acorn_partition_map
)
145 grub_partition_map_unregister (&grub_acorn_partition_map
);