mirror of
https://github.com/RGBCube/serenity
synced 2025-05-18 09:15:08 +00:00
5ed3f7c6bf
That code used the old AK::Result container, which leads to overly complicated initialization flow when trying to figure out the correct partition table type. Instead, when using the ErrorOr container the code is much simpler and more understandable.
119 lines
3.6 KiB
C++
119 lines
3.6 KiB
C++
/*
|
|
* Copyright (c) 2020-2022, Liav A. <liavalb@hotmail.co.il>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/ByteBuffer.h>
|
|
#include <Kernel/Debug.h>
|
|
#include <Kernel/Storage/Partition/MBRPartitionTable.h>
|
|
|
|
namespace Kernel {
|
|
|
|
#define MBR_SIGNATURE 0xaa55
|
|
#define MBR_PROTECTIVE 0xEE
|
|
#define EBR_CHS_CONTAINER 0x05
|
|
#define EBR_LBA_CONTAINER 0x0F
|
|
|
|
ErrorOr<NonnullOwnPtr<MBRPartitionTable>> MBRPartitionTable::try_to_initialize(StorageDevice const& device)
|
|
{
|
|
auto table = TRY(adopt_nonnull_own_or_enomem(new (nothrow) MBRPartitionTable(device)));
|
|
if (table->contains_ebr())
|
|
return Error::from_errno(ENOTSUP);
|
|
if (table->is_protective_mbr())
|
|
return Error::from_errno(ENOTSUP);
|
|
if (!table->is_valid())
|
|
return Error::from_errno(EINVAL);
|
|
return table;
|
|
}
|
|
|
|
OwnPtr<MBRPartitionTable> MBRPartitionTable::try_to_initialize(StorageDevice const& device, u32 start_lba)
|
|
{
|
|
auto table = adopt_nonnull_own_or_enomem(new (nothrow) MBRPartitionTable(device, start_lba)).release_value_but_fixme_should_propagate_errors();
|
|
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(StorageDevice const& device, u32 start_lba)
|
|
: PartitionTable(device)
|
|
, m_start_lba(start_lba)
|
|
, m_cached_header(ByteBuffer::create_zeroed(m_device->block_size()).release_value_but_fixme_should_propagate_errors()) // FIXME: Do something sensible if this fails because of OOM.
|
|
{
|
|
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;
|
|
}
|
|
MUST(m_partitions.try_empend(entry.offset, (entry.offset + entry.length), entry.type));
|
|
}
|
|
m_valid = true;
|
|
}
|
|
|
|
MBRPartitionTable::MBRPartitionTable(StorageDevice const& device)
|
|
: PartitionTable(device)
|
|
, m_start_lba(0)
|
|
, m_cached_header(ByteBuffer::create_zeroed(m_device->block_size()).release_value_but_fixme_should_propagate_errors()) // FIXME: Do something sensible if this fails because of OOM.
|
|
{
|
|
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;
|
|
}
|
|
MUST(m_partitions.try_empend(entry.offset, (entry.offset + entry.length), entry.type));
|
|
}
|
|
m_valid = true;
|
|
}
|
|
|
|
MBRPartitionTable::~MBRPartitionTable() = default;
|
|
|
|
MBRPartitionTable::Header const& MBRPartitionTable::header() const
|
|
{
|
|
return *(MBRPartitionTable::Header const*)m_cached_header.data();
|
|
}
|
|
|
|
bool MBRPartitionTable::initialize()
|
|
{
|
|
auto& header = this->header();
|
|
dbgln_if(MBR_DEBUG, "Master Boot Record: mbr_signature={:#08x}", header.mbr_signature);
|
|
if (header.mbr_signature != MBR_SIGNATURE) {
|
|
dbgln("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;
|
|
}
|
|
|
|
}
|