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/*
* 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/AllOf.h>
#include <AK/Array.h>
#include <Kernel/Debug.h>
#include <Kernel/Storage/Partition/GUIDPartitionTable.h>
namespace Kernel {
#define GPT_SIGNATURE2 0x54524150
#define GPT_SIGNATURE 0x20494645
#define BytesPerSector 512
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;
};
Result<NonnullOwnPtr<GUIDPartitionTable>, PartitionTable::Error> GUIDPartitionTable::try_to_initialize(const StorageDevice& device)
{
auto table = make<GUIDPartitionTable>(device);
if (!table->is_valid())
return { PartitionTable::Error::Invalid };
return table;
}
GUIDPartitionTable::GUIDPartitionTable(const StorageDevice& device)
: MBRPartitionTable(device)
{
m_cached_header = ByteBuffer::create_zeroed(m_device->block_size());
VERIFY(partitions_count() == 0);
if (!initialize())
m_valid = false;
}
const GUIDPartitionHeader& GUIDPartitionTable::header() const
{
return *(const GUIDPartitionHeader*)m_cached_header.data();
}
bool GUIDPartitionTable::initialize()
{
VERIFY(m_cached_header.data() != nullptr);
auto first_gpt_block = (m_device->block_size() == 512) ? 1 : 0;
auto buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_header.data());
if (!m_device->read_block(first_gpt_block, buffer)) {
return false;
}
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 = ByteBuffer::create_zeroed(m_device->block_size());
auto raw_entries_buffer = UserOrKernelBuffer::for_kernel_buffer(entries_buffer.data());
size_t raw_byte_index = header().partition_array_start_lba * m_device->block_size();
for (size_t entry_index = 0; entry_index < header().entries_count; entry_index++) {
if (!m_device->read_block((raw_byte_index / m_device->block_size()), raw_entries_buffer)) {
return false;
}
auto* entries = (const GPTPartitionEntry*)entries_buffer.data();
auto& entry = entries[entry_index % (m_device->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());
String name = entry.partition_name;
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.begin(), partition_type.end(), [](const auto octet) { return octet == 0; });
}
}
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