1 /* sunpc.c - Read SUN PC style partition tables. */
2 /*
3 * GRUB -- GRand Unified Bootloader
4 * Copyright (C) 2002,2005,2006,2007,2009 Free Software Foundation, Inc.
5 *
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.
10 *
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.
15 *
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/>.
18 */
19
20 #include <grub/partition.h>
21 #include <grub/disk.h>
22 #include <grub/mm.h>
23 #include <grub/misc.h>
24 #include <grub/dl.h>
25 #include <grub/symbol.h>
26 #include <grub/types.h>
27 #include <grub/err.h>
28
29 GRUB_MOD_LICENSE ("GPLv3+");
30
31 #define GRUB_PARTMAP_SUN_PC_MAGIC 0xDABE
32 #define GRUB_PARTMAP_SUN_PC_MAX_PARTS 16
33 #define GRUB_PARTMAP_SUN_PC_WHOLE_DISK_ID 0x05
34
35 struct grub_sun_pc_partition_descriptor
36 {
37 grub_uint16_t id;
38 grub_uint16_t unused;
39 grub_uint32_t start_sector;
40 grub_uint32_t num_sectors;
41 } __attribute__ ((packed));
42
43 struct grub_sun_pc_block
44 {
45 grub_uint8_t unused[72];
46 struct grub_sun_pc_partition_descriptor partitions[GRUB_PARTMAP_SUN_PC_MAX_PARTS];
47 grub_uint8_t unused2[244];
48 grub_uint16_t magic; /* Magic number. */
49 grub_uint16_t csum; /* Label xor'd checksum. */
50 } __attribute__ ((packed));
51
52 static struct grub_partition_map grub_sun_pc_partition_map;
53
54 /* Verify checksum (true=ok). */
55 static int
56 grub_sun_is_valid (grub_uint16_t *label)
57 {
58 grub_uint16_t *pos;
59 grub_uint16_t sum = 0;
60
61 for (pos = label;
62 pos < (label + sizeof (struct grub_sun_pc_block) / 2);
63 pos++)
64 sum ^= *pos;
65
66 return ! sum;
67 }
68
69 static grub_err_t
70 sun_pc_partition_map_iterate (grub_disk_t disk,
71 int (*hook) (grub_disk_t disk,
72 const grub_partition_t partition))
73 {
74 grub_partition_t p;
75 union
76 {
77 struct grub_sun_pc_block sunb;
78 grub_uint16_t raw[0];
79 } block;
80 int partnum;
81 grub_err_t err;
82
83 p = (grub_partition_t) grub_zalloc (sizeof (struct grub_partition));
84 if (! p)
85 return grub_errno;
86
87 p->partmap = &grub_sun_pc_partition_map;
88 err = grub_disk_read (disk, 1, 0, sizeof (struct grub_sun_pc_block), &block);
89 if (err)
90 {
91 grub_free (p);
92 return err;
93 }
94
95 if (GRUB_PARTMAP_SUN_PC_MAGIC != grub_le_to_cpu16 (block.sunb.magic))
96 {
97 grub_free (p);
98 return grub_error (GRUB_ERR_BAD_PART_TABLE,
99 "not a sun_pc partition table");
100 }
101
102 if (! grub_sun_is_valid (block.raw))
103 {
104 grub_free (p);
105 return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid checksum");
106 }
107
108 /* Maybe another error value would be better, because partition
109 table _is_ recognized but invalid. */
110 for (partnum = 0; partnum < GRUB_PARTMAP_SUN_PC_MAX_PARTS; partnum++)
111 {
112 struct grub_sun_pc_partition_descriptor *desc;
113
114 if (block.sunb.partitions[partnum].id == 0
115 || block.sunb.partitions[partnum].id
116 == GRUB_PARTMAP_SUN_PC_WHOLE_DISK_ID)
117 continue;
118
119 desc = &block.sunb.partitions[partnum];
120 p->start = grub_le_to_cpu32 (desc->start_sector);
121 p->len = grub_le_to_cpu32 (desc->num_sectors);
122 p->number = partnum;
123 if (p->len)
124 {
125 if (hook (disk, p))
126 partnum = GRUB_PARTMAP_SUN_PC_MAX_PARTS;
127 }
128 }
129
130 grub_free (p);
131
132 return grub_errno;
133 }
134
135 /* Partition map type. */
136 static struct grub_partition_map grub_sun_pc_partition_map =
137 {
138 .name = "sunpc",
139 .iterate = sun_pc_partition_map_iterate,
140 };
141
142 GRUB_MOD_INIT(part_sunpc)
143 {
144 grub_partition_map_register (&grub_sun_pc_partition_map);
145 }
146
147 GRUB_MOD_FINI(part_sunpc)
148 {
149 grub_partition_map_unregister (&grub_sun_pc_partition_map);
150 }
151