1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
* Copyright (c) 2020-2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Debug.h>
#include <LibPartition/GUIDPartitionTable.h>
namespace Partition {
#define GPT_SIGNATURE2 0x54524150
#define GPT_SIGNATURE 0x20494645
struct [[gnu::packed]] GPTPartitionEntry {
u8 partition_guid[16];
u8 unique_guid[16];
u64 first_lba;
u64 last_lba;
u64 attributes;
char partition_name[72];
};
struct [[gnu::packed]] GUIDPartitionHeader {
u32 sig[2];
u32 revision;
u32 header_size;
u32 crc32_header;
u32 reserved;
u64 current_lba;
u64 backup_lba;
u64 first_usable_lba;
u64 last_usable_lba;
u64 disk_guid1[2];
u64 partition_array_start_lba;
u32 entries_count;
u32 partition_entry_size;
u32 crc32_entries_array;
};
#ifdef KERNEL
ErrorOr<NonnullOwnPtr<GUIDPartitionTable>> GUIDPartitionTable::try_to_initialize(Kernel::StorageDevice const& device)
{
auto table = TRY(adopt_nonnull_own_or_enomem(new (nothrow) GUIDPartitionTable(device)));
#else
ErrorOr<NonnullOwnPtr<GUIDPartitionTable>> GUIDPartitionTable::try_to_initialize(NonnullRefPtr<Core::File> device_file)
{
auto table = TRY(adopt_nonnull_own_or_enomem(new (nothrow) GUIDPartitionTable(move(device_file))));
#endif
if (!table->is_valid())
return Error::from_errno(EINVAL);
return table;
}
#ifdef KERNEL
GUIDPartitionTable::GUIDPartitionTable(Kernel::StorageDevice const& device)
: MBRPartitionTable(device)
#else
GUIDPartitionTable::GUIDPartitionTable(NonnullRefPtr<Core::File> device_file)
: MBRPartitionTable(move(device_file))
#endif
{
// FIXME: Handle OOM failure here.
m_cached_header = ByteBuffer::create_zeroed(m_block_size).release_value_but_fixme_should_propagate_errors();
VERIFY(partitions_count() == 0);
if (!initialize())
m_valid = false;
}
GUIDPartitionHeader const& GUIDPartitionTable::header() const
{
return *(GUIDPartitionHeader const*)m_cached_header.data();
}
bool GUIDPartitionTable::initialize()
{
VERIFY(m_cached_header.data() != nullptr);
auto first_gpt_block = (m_block_size == 512) ? 1 : 0;
#ifdef KERNEL
auto buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_header.data());
if (!m_device->read_block(first_gpt_block, buffer))
return false;
#else
m_device_file->seek(first_gpt_block * m_block_size);
if (m_device_file->read(m_cached_header.data(), m_cached_header.size()) != (int)m_block_size)
return false;
#endif
dbgln_if(GPT_DEBUG, "GUIDPartitionTable: signature - {:#08x} {:#08x}", header().sig[1], header().sig[0]);
if (header().sig[0] != GPT_SIGNATURE && header().sig[1] != GPT_SIGNATURE2) {
dbgln("GUIDPartitionTable: bad signature {:#08x} {:#08x}", header().sig[1], header().sig[0]);
return false;
}
auto entries_buffer_result = ByteBuffer::create_zeroed(m_block_size);
if (entries_buffer_result.is_error()) {
dbgln("GUIDPartitionTable: not enough memory for entries buffer");
return false;
}
auto entries_buffer = entries_buffer_result.release_value();
#ifdef KERNEL
auto raw_entries_buffer = UserOrKernelBuffer::for_kernel_buffer(entries_buffer.data());
#endif
size_t raw_byte_index = header().partition_array_start_lba * m_block_size;
for (size_t entry_index = 0; entry_index < header().entries_count; entry_index++) {
#ifdef KERNEL
if (!m_device->read_block((raw_byte_index / m_block_size), raw_entries_buffer))
return false;
#else
m_device_file->seek(raw_byte_index);
if (m_device_file->read(entries_buffer.data(), entries_buffer.size()) != (int)m_block_size)
return false;
#endif
auto* entries = (GPTPartitionEntry const*)entries_buffer.data();
auto& entry = entries[entry_index % (m_block_size / (size_t)header().partition_entry_size)];
Array<u8, 16> partition_type {};
partition_type.span().overwrite(0, entry.partition_guid, partition_type.size());
if (is_unused_entry(partition_type)) {
raw_byte_index += header().partition_entry_size;
continue;
}
Array<u8, 16> unique_guid {};
unique_guid.span().overwrite(0, entry.unique_guid, unique_guid.size());
dbgln("Detected GPT partition (entry={}), offset={}, limit={}", entry_index, entry.first_lba, entry.last_lba);
m_partitions.append({ entry.first_lba, entry.last_lba, partition_type, unique_guid, entry.attributes });
raw_byte_index += header().partition_entry_size;
}
return true;
}
bool GUIDPartitionTable::is_unused_entry(Array<u8, 16> partition_type) const
{
return all_of(partition_type, [](auto const octet) { return octet == 0; });
}
}
|
