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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/ByteBuffer.h>
#include <Kernel/Devices/EBRPartitionTable.h>
#ifndef EBR_DEBUG
# define EBR_DEBUG
#endif
namespace Kernel {
EBRPartitionTable::EBRPartitionTable(NonnullRefPtr<BlockDevice> device)
: m_device(move(device))
{
}
EBRPartitionTable::~EBRPartitionTable()
{
}
const MBRPartitionHeader& EBRPartitionTable::header() const
{
return *reinterpret_cast<const MBRPartitionHeader*>(m_cached_mbr_header);
}
const EBRPartitionExtension& EBRPartitionTable::ebr_extension() const
{
return *reinterpret_cast<const EBRPartitionExtension*>(m_cached_ebr_header);
}
int EBRPartitionTable::index_of_ebr_container() const
{
for (int i = 0; i < 4; i++) {
if (header().entry[i].type == EBR_CHS_CONTAINER || header().entry[i].type == EBR_LBA_CONTAINER)
return i;
}
ASSERT_NOT_REACHED();
}
bool EBRPartitionTable::initialize()
{
auto mbr_header_request = m_device->make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read,
0, 1, UserOrKernelBuffer::for_kernel_buffer(m_cached_mbr_header), sizeof(m_cached_mbr_header));
auto mbr_header_buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_mbr_header);
if (!m_device->read_block(0, mbr_header_buffer)) {
return false;
}
auto& header = this->header();
m_ebr_container_id = index_of_ebr_container() + 1;
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::initialize: MBR_signature=0x" << String::format("%x", header.mbr_signature);
#endif
if (header.mbr_signature != MBR_SIGNATURE) {
klog() << "EBRPartitionTable::initialize: bad MBR signature 0x" << String::format("%x", header.mbr_signature);
return false;
}
auto& ebr_entry = header.entry[m_ebr_container_id - 1];
auto ebr_header_buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_ebr_header);
if (!m_device->read_block(ebr_entry.offset, ebr_header_buffer)) {
return false;
}
size_t index = 1;
while (index < 128) { // Unlikely to encounter a disk with 128 partitions in this configuration...
if (ebr_extension().next_chained_ebr_extension.offset == 0 && ebr_extension().next_chained_ebr_extension.type == 0) {
break;
}
index++;
if (!m_device->read_block(ebr_extension().next_chained_ebr_extension.offset, ebr_header_buffer)) {
return false;
}
}
m_ebr_chained_extensions_count = index;
klog() << "EBRPartitionTable::initialize: Extended partitions count - " << m_ebr_chained_extensions_count;
return true;
}
RefPtr<DiskPartition> EBRPartitionTable::get_non_extended_partition(unsigned index)
{
auto& header = this->header();
auto& entry = header.entry[index - 1];
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: status=0x" << String::format("%x", entry.status) << " offset=0x" << String::format("%x", entry.offset);
#endif
if (entry.offset == 0x00) {
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: missing partition requested index=" << index;
#endif
return nullptr;
}
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: found partition index=" << index << " type=" << String::format("%x", entry.type);
#endif
return DiskPartition::create(m_device, entry.offset, (entry.offset + entry.length));
}
RefPtr<DiskPartition> EBRPartitionTable::get_extended_partition(unsigned index)
{
unsigned relative_index = index - m_ebr_container_id;
auto& header = this->header();
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: relative index " << relative_index;
#endif
auto& ebr_entry = header.entry[m_ebr_container_id - 1];
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: Extended partition, offset 0x" << String::format("%x", ebr_entry.offset) << ", type " << String::format("%x", ebr_entry.type);
#endif
auto ebr_header_buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_ebr_header);
if (!m_device->read_block(ebr_entry.offset, ebr_header_buffer)) {
return nullptr;
}
size_t i = 0;
while (i < relative_index) {
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: logical partition, relative offset 0x" << String::format("%x", ebr_extension().entry.offset) << ", type " << String::format("%x", ebr_extension().entry.type);
klog() << "EBRPartitionTable::partition: next logical partition, relative offset 0x" << String::format("%x", ebr_extension().next_chained_ebr_extension.offset) << ", type " << String::format("%x", ebr_extension().next_chained_ebr_extension.type);
#endif
if (ebr_extension().next_chained_ebr_extension.offset == 0 && ebr_extension().next_chained_ebr_extension.type == 0) {
break;
}
i++;
if (!m_device->read_block(ebr_extension().next_chained_ebr_extension.offset, ebr_header_buffer)) {
return nullptr;
}
}
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: status=" << String::format("%x", ebr_extension().entry.status) << " offset=" << String::format("%x", ebr_extension().entry.offset + ebr_entry.offset);
#endif
if (ebr_extension().entry.offset == 0x00) {
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: missing partition requested index=" << index;
#endif
return nullptr;
}
#ifdef EBR_DEBUG
klog() << "EBRPartitionTable::partition: found partition index=" << index << " type=" << String::format("%x", ebr_extension().entry.type);
#endif
return DiskPartition::create(m_device, ebr_extension().entry.offset + ebr_entry.offset, (ebr_extension().entry.offset + ebr_entry.offset + ebr_extension().entry.length));
}
bool EBRPartitionTable::index_is_extended_partition(unsigned index) const
{
return !(m_ebr_container_id > index || index > (m_ebr_container_id + m_ebr_chained_extensions_count));
}
RefPtr<DiskPartition> EBRPartitionTable::partition(unsigned index)
{
ASSERT(index >= 1 && index <= m_ebr_chained_extensions_count + 4);
auto& header = this->header();
if (header.mbr_signature != MBR_SIGNATURE) {
klog() << "EBRPartitionTable::initialize: bad MBR signature - not initialized? 0x" << String::format("%x", header.mbr_signature);
return nullptr;
}
if (index_is_extended_partition(index))
return get_extended_partition(index);
if (index > 4)
return get_non_extended_partition(index - m_ebr_chained_extensions_count);
return get_non_extended_partition(index);
}
}
|
