1 /* acorn.c - Read Linux/ADFS partition tables. */
3 * GRUB -- GRand Unified Bootloader
4 * Copyright (C) 2005 Free Software Foundation, Inc.
6 * This program 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 2 of the License, or
9 * (at your option) any later version.
11 * This program 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 this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <grub/disk.h>
22 #include <grub/misc.h>
24 #include <grub/partition.h>
25 #include <grub/acorn_filecore.h>
27 #define LINUX_NATIVE_MAGIC grub_cpu_to_le32 (0xdeafa1de)
28 #define LINUX_SWAP_MAGIC grub_cpu_to_le32 (0xdeafab1e)
29 #define LINUX_MAP_ENTRIES (512 / 12)
31 #define NONADFS_PARTITON_TYPE_LINUX 9
32 #define NONADFS_PARTITON_TYPE_MASK 15
34 struct grub_acorn_boot_block
36 grub_uint8_t misc
[0x1C0];
37 struct grub_filecore_disc_record disc_record
;
39 grub_uint16_t start_cylinder
;
40 grub_uint8_t checksum
;
41 } __attribute__ ((packed
, aligned
));
50 static struct grub_partition_map grub_acorn_partition_map
;
53 acorn_partition_map_find (grub_disk_t disk
, struct linux_part
*m
,
56 struct grub_acorn_boot_block boot
;
58 unsigned int checksum
= 0;
60 unsigned int sectors_per_cylinder
;
63 err
= grub_disk_read (disk
, 0xC00 / GRUB_DISK_SECTOR_SIZE
, 0,
64 sizeof (struct grub_acorn_boot_block
),
69 if ((boot
.flags
& NONADFS_PARTITON_TYPE_MASK
) != NONADFS_PARTITON_TYPE_LINUX
)
72 for (i
= 0; i
!= 0x1ff; ++i
)
73 checksum
= (checksum
& 0xff) + (checksum
>> 8) + boot
.misc
[i
];
75 if ((grub_uint8_t
) checksum
!= boot
.checksum
)
78 heads
= (boot
.disc_record
.heads
79 + ((boot
.disc_record
.lowsector
>> 6) & 1));
80 sectors_per_cylinder
= boot
.disc_record
.secspertrack
* heads
;
81 *sector
= grub_le_to_cpu16 (boot
.start_cylinder
) * sectors_per_cylinder
;
83 return grub_disk_read (disk
, *sector
, 0,
84 sizeof (struct linux_part
) * LINUX_MAP_ENTRIES
,
88 return grub_error (GRUB_ERR_BAD_PART_TABLE
,
89 "Linux/ADFS partition map not found.");
95 acorn_partition_map_iterate (grub_disk_t disk
,
96 int (*hook
) (grub_disk_t disk
,
97 const grub_partition_t partition
))
99 struct grub_partition part
;
100 struct grub_disk raw
;
101 struct linux_part map
[LINUX_MAP_ENTRIES
];
106 /* Enforce raw disk access. */
110 err
= acorn_partition_map_find (&raw
, map
, §or
);
114 part
.partmap
= &grub_acorn_partition_map
;
116 for (i
= 0; i
!= LINUX_MAP_ENTRIES
; ++i
)
118 if (map
[i
].magic
!= LINUX_NATIVE_MAGIC
119 && map
[i
].magic
!= LINUX_SWAP_MAGIC
)
120 return GRUB_ERR_NONE
;
122 part
.start
= (grub_disk_addr_t
)sector
+ map
[i
].start
;
123 part
.len
= map
[i
].size
;
127 if (hook (disk
, &part
))
131 return GRUB_ERR_NONE
;
135 static grub_partition_t
136 acorn_partition_map_probe (grub_disk_t disk
, const char *str
)
138 struct linux_part map
[LINUX_MAP_ENTRIES
];
139 struct grub_disk raw
= *disk
;
140 unsigned long partnum
= grub_strtoul (str
, 0, 10);
144 /* Enforce raw disk access. */
147 /* Get the partition number. */
148 if (partnum
> LINUX_MAP_ENTRIES
)
151 err
= acorn_partition_map_find (&raw
, map
, §or
);
155 if (map
[partnum
].magic
!= LINUX_NATIVE_MAGIC
156 && map
[partnum
].magic
!= LINUX_SWAP_MAGIC
)
159 grub_partition_t p
= grub_malloc (sizeof (struct grub_partition
));
163 p
->start
= (grub_disk_addr_t
)sector
+ map
[partnum
].start
;
164 p
->len
= map
[partnum
].size
;
170 grub_error (GRUB_ERR_BAD_FILENAME
, "invalid partition");
176 acorn_partition_map_get_name (const grub_partition_t p
)
180 name
= grub_malloc (13);
184 grub_sprintf (name
, "%d", p
->index
);
189 /* Partition map type. */
190 static struct grub_partition_map grub_acorn_partition_map
=
192 .name
= "Linux/ADFS partition map",
193 .iterate
= acorn_partition_map_iterate
,
194 .probe
= acorn_partition_map_probe
,
195 .get_name
= acorn_partition_map_get_name
198 GRUB_MOD_INIT(acorn_partition_map
)
200 grub_partition_map_register (&grub_acorn_partition_map
);
203 GRUB_MOD_FINI(acorn_partition_map
)
205 grub_partition_map_unregister (&grub_acorn_partition_map
);