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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/ByteBuffer.h>
#include <Kernel/Storage/Partition/MBRPartitionTable.h>
#ifndef MBR_DEBUG
# define MBR_DEBUG
#endif
namespace Kernel {
#define MBR_SIGNATURE 0xaa55
#define MBR_PROTECTIVE 0xEE
#define EBR_CHS_CONTAINER 0x05
#define EBR_LBA_CONTAINER 0x0F
Result<NonnullOwnPtr<MBRPartitionTable>, PartitionTable::Error> MBRPartitionTable::try_to_initialize(const StorageDevice& device)
{
auto table = make<MBRPartitionTable>(device);
if (table->contains_ebr())
return { PartitionTable::Error::ConatinsEBR };
if (table->is_protective_mbr())
return { PartitionTable::Error::MBRProtective };
if (!table->is_valid())
return { PartitionTable::Error::Invalid };
return table;
}
OwnPtr<MBRPartitionTable> MBRPartitionTable::try_to_initialize(const StorageDevice& device, u32 start_lba)
{
auto table = make<MBRPartitionTable>(device, start_lba);
if (!table->is_valid())
return {};
return table;
}
bool MBRPartitionTable::read_boot_record()
{
auto buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_header.data());
if (!m_device->read_block(m_start_lba, buffer))
return false;
m_header_valid = true;
return m_header_valid;
}
MBRPartitionTable::MBRPartitionTable(const StorageDevice& device, u32 start_lba)
: PartitionTable(device)
, m_start_lba(start_lba)
, m_cached_header(ByteBuffer::create_zeroed(m_device->block_size()))
{
if (!read_boot_record() || !initialize())
return;
m_header_valid = true;
auto& header = this->header();
for (size_t index = 0; index < 4; index++) {
auto& entry = header.entry[index];
if (entry.offset == 0x00) {
continue;
}
auto partition_type = ByteBuffer::create_zeroed(sizeof(u8));
partition_type.data()[0] = entry.type;
m_partitions.append(DiskPartitionMetadata({ entry.offset, (entry.offset + entry.length), partition_type }));
}
m_valid = true;
}
MBRPartitionTable::MBRPartitionTable(const StorageDevice& device)
: PartitionTable(device)
, m_start_lba(0)
, m_cached_header(ByteBuffer::create_zeroed(m_device->block_size()))
{
if (!read_boot_record() || contains_ebr() || is_protective_mbr() || !initialize())
return;
auto& header = this->header();
for (size_t index = 0; index < 4; index++) {
auto& entry = header.entry[index];
if (entry.offset == 0x00) {
continue;
}
auto partition_type = ByteBuffer::create_zeroed(sizeof(u8));
partition_type.data()[0] = entry.type;
m_partitions.append(DiskPartitionMetadata({ entry.offset, (entry.offset + entry.length), partition_type }));
}
m_valid = true;
}
MBRPartitionTable::~MBRPartitionTable()
{
}
const MBRPartitionTable::Header& MBRPartitionTable::header() const
{
return *(const MBRPartitionTable::Header*)m_cached_header.data();
}
bool MBRPartitionTable::initialize()
{
auto& header = this->header();
#ifdef MBR_DEBUG
klog() << "Master Boot Record: mbr_signature=0x" << String::format("%x", header.mbr_signature);
#endif
if (header.mbr_signature != MBR_SIGNATURE) {
klog() << "Master Boot Record: invalid signature";
return false;
}
return true;
}
bool MBRPartitionTable::contains_ebr() const
{
for (int i = 0; i < 4; i++) {
if (header().entry[i].type == EBR_CHS_CONTAINER || header().entry[i].type == EBR_LBA_CONTAINER)
return true;
}
return false;
}
bool MBRPartitionTable::is_protective_mbr() const
{
return header().entry[0].type == MBR_PROTECTIVE;
}
}
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