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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/ByteBuffer.h>
#include <Kernel/Storage/Partition/EBRPartitionTable.h>
namespace Kernel {
Result<NonnullOwnPtr<EBRPartitionTable>, PartitionTable::Error> EBRPartitionTable::try_to_initialize(const StorageDevice& device)
{
auto table = adopt_nonnull_own_or_enomem(new (nothrow) EBRPartitionTable(device)).release_value_but_fixme_should_propagate_errors();
if (table->is_protective_mbr())
return { PartitionTable::Error::MBRProtective };
if (!table->is_valid())
return { PartitionTable::Error::Invalid };
return table;
}
void EBRPartitionTable::search_extended_partition(const StorageDevice& device, MBRPartitionTable& checked_ebr, u64 current_block_offset, size_t limit)
{
if (limit == 0)
return;
// EBRs should not carry more than 2 partitions (because they need to form a linked list)
VERIFY(checked_ebr.partitions_count() <= 2);
auto checked_logical_partition = checked_ebr.partition(0);
// If we are pointed to an invalid logical partition, something is seriously wrong.
VERIFY(checked_logical_partition.has_value());
m_partitions.append(checked_logical_partition.value().offset(current_block_offset));
if (!checked_ebr.contains_ebr())
return;
current_block_offset += checked_ebr.partition(1).value().start_block();
auto next_ebr = MBRPartitionTable::try_to_initialize(device, current_block_offset);
if (!next_ebr)
return;
search_extended_partition(device, *next_ebr, current_block_offset, (limit - 1));
}
EBRPartitionTable::EBRPartitionTable(const StorageDevice& device)
: MBRPartitionTable(device)
{
if (!is_header_valid())
return;
m_valid = true;
VERIFY(partitions_count() == 0);
auto& header = this->header();
for (size_t index = 0; index < 4; index++) {
auto& entry = header.entry[index];
// Start enumerating all logical partitions
if (entry.type == 0xf) {
auto checked_ebr = MBRPartitionTable::try_to_initialize(device, entry.offset);
if (!checked_ebr)
continue;
// It's quite unlikely to see that amount of partitions, so stop at 128 partitions.
search_extended_partition(device, *checked_ebr, entry.offset, 128);
continue;
}
if (entry.offset == 0x00) {
continue;
}
MUST(m_partitions.try_empend(entry.offset, (entry.offset + entry.length), entry.type));
}
}
EBRPartitionTable::~EBRPartitionTable() = default;
}
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