1
/* pc.c - Read PC style partition tables. */
3
* GRUB -- GRand Unified Bootloader
4
* Copyright (C) 2002,2004,2005,2006,2007,2008,2009 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/partition.h>
21
#include <grub/msdos_partition.h>
22
#include <grub/disk.h>
24
#include <grub/misc.h>
27
static struct grub_partition_map grub_msdos_partition_map;
30
/* Parse the partition representation in STR and return a partition. */
31
static grub_partition_t
32
grub_partition_parse (const char *str)
35
struct grub_msdos_partition *pcdata;
37
char *s = (char *) str;
39
p = (grub_partition_t) grub_malloc (sizeof (*p));
43
pcdata = (struct grub_msdos_partition *) grub_malloc (sizeof (*pcdata));
48
p->partmap = &grub_msdos_partition_map;
50
/* Initialize some of the fields with invalid values. */
51
pcdata->bsd_part = pcdata->dos_type = pcdata->bsd_type = p->index = -1;
53
/* Get the DOS partition number. The number is counted from one for
54
the user interface, and from zero internally. */
55
pcdata->dos_part = grub_strtoul (s, &s, 0) - 1;
59
/* Not found. Maybe only a BSD label is specified. */
60
pcdata->dos_part = -1;
61
grub_errno = GRUB_ERR_NONE;
68
if (*s >= 'a' && *s <= 'h')
70
pcdata->bsd_part = *s - 'a';
78
if (pcdata->dos_part == -1 && pcdata->bsd_part == -1)
86
grub_error (GRUB_ERR_BAD_FILENAME, "invalid partition");
91
pc_partition_map_iterate (grub_disk_t disk,
92
int (*hook) (grub_disk_t disk,
93
const grub_partition_t partition))
95
struct grub_partition p;
96
struct grub_msdos_partition pcdata;
97
struct grub_msdos_partition_mbr mbr;
98
struct grub_msdos_partition_disk_label label;
101
/* Enforce raw disk access. */
106
pcdata.ext_offset = 0;
107
pcdata.dos_part = -1;
109
p.partmap = &grub_msdos_partition_map;
114
struct grub_msdos_partition_entry *e;
117
if (grub_disk_read (&raw, p.offset, 0, sizeof (mbr), &mbr))
120
/* Check if it is valid. */
121
if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
122
return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
124
for (i = 0; i < 4; i++)
125
if (mbr.entries[i].flag & 0x7f)
126
return grub_error (GRUB_ERR_BAD_PART_TABLE, "bad boot flag");
128
/* Analyze DOS partitions. */
129
for (p.index = 0; p.index < 4; p.index++)
131
e = mbr.entries + p.index;
133
p.start = p.offset + grub_le_to_cpu32 (e->start);
134
p.len = grub_le_to_cpu32 (e->length);
135
pcdata.bsd_part = -1;
136
pcdata.dos_type = e->type;
137
pcdata.bsd_type = -1;
139
grub_dprintf ("partition",
140
"partition %d: flag 0x%x, type 0x%x, start 0x%llx, len 0x%llx\n",
141
p.index, e->flag, pcdata.dos_type,
142
(unsigned long long) p.start,
143
(unsigned long long) p.len);
145
/* If this is a GPT partition, this MBR is just a dummy. */
146
if (e->type == GRUB_PC_PARTITION_TYPE_GPT_DISK && p.index == 0)
147
return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr");
149
/* If this partition is a normal one, call the hook. */
150
if (! grub_msdos_partition_is_empty (e->type)
151
&& ! grub_msdos_partition_is_extended (e->type))
158
/* Check if this is a BSD partition. */
159
if (grub_msdos_partition_is_bsd (e->type))
161
/* Check if the BSD label is within the DOS partition. */
162
if (p.len <= GRUB_PC_PARTITION_BSD_LABEL_SECTOR)
164
grub_dprintf ("partition", "no space for disk label\n");
167
/* Read the BSD label. */
168
if (grub_disk_read (&raw,
170
+ GRUB_PC_PARTITION_BSD_LABEL_SECTOR),
176
/* Check if it is valid. */
178
!= grub_cpu_to_le32 (GRUB_PC_PARTITION_BSD_LABEL_MAGIC))
180
grub_dprintf ("partition",
181
"invalid disk label magic 0x%x on partition %d\n",
182
label.magic, p.index);
185
for (pcdata.bsd_part = 0;
186
pcdata.bsd_part < grub_cpu_to_le16 (label.num_partitions);
189
struct grub_msdos_partition_bsd_entry *be
190
= label.entries + pcdata.bsd_part;
192
p.start = grub_le_to_cpu32 (be->offset);
193
p.len = grub_le_to_cpu32 (be->size);
194
pcdata.bsd_type = be->fs_type;
196
if (be->fs_type != GRUB_PC_PARTITION_BSD_TYPE_UNUSED)
202
else if (pcdata.dos_part < 4)
203
/* If this partition is a logical one, shouldn't increase the
208
/* Find an extended partition. */
209
for (i = 0; i < 4; i++)
213
if (grub_msdos_partition_is_extended (e->type))
215
p.offset = pcdata.ext_offset + grub_le_to_cpu32 (e->start);
216
if (! pcdata.ext_offset)
217
pcdata.ext_offset = p.offset;
223
/* If no extended partition, the end. */
233
static grub_partition_t
234
pc_partition_map_probe (grub_disk_t disk, const char *str)
237
struct grub_msdos_partition *pcdata;
239
auto int find_func (grub_disk_t d, const grub_partition_t partition);
241
int find_func (grub_disk_t d __attribute__ ((unused)),
242
const grub_partition_t partition)
244
struct grub_msdos_partition *partdata = partition->data;
246
if ((pcdata->dos_part == partdata->dos_part || pcdata->dos_part == -1)
247
&& pcdata->bsd_part == partdata->bsd_part)
249
grub_memcpy (p, partition, sizeof (*p));
251
grub_memcpy (pcdata, partdata, sizeof (*pcdata));
258
p = grub_partition_parse (str);
263
pc_partition_map_iterate (disk, find_func);
269
grub_error (GRUB_ERR_BAD_DEVICE, "no such partition");
283
pc_partition_map_get_name (const grub_partition_t p)
286
struct grub_msdos_partition *pcdata = p->data;
288
name = grub_malloc (13);
292
if (pcdata->bsd_part < 0)
293
grub_sprintf (name, "%d", pcdata->dos_part + 1);
294
else if (pcdata->dos_part < 0)
295
grub_sprintf (name, "%c", pcdata->bsd_part + 'a');
297
grub_sprintf (name, "%d,%c", pcdata->dos_part + 1, pcdata->bsd_part + 'a');
303
/* Partition map type. */
304
static struct grub_partition_map grub_msdos_partition_map =
306
.name = "part_msdos",
307
.iterate = pc_partition_map_iterate,
308
.probe = pc_partition_map_probe,
309
.get_name = pc_partition_map_get_name
312
GRUB_MOD_INIT(pc_partition_map)
314
grub_partition_map_register (&grub_msdos_partition_map);
317
GRUB_MOD_FINI(pc_partition_map)
319
grub_partition_map_unregister (&grub_msdos_partition_map);