mirror of
https://github.com/RGBCube/serenity
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92 lines
2.9 KiB
C++
92 lines
2.9 KiB
C++
/*
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* Copyright (c) 2022, Undefine <undefine@undefine.pl>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/OwnPtr.h>
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#include <AK/RefPtr.h>
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#include <AK/Types.h>
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#include <Kernel/FileSystem/BlockBasedFileSystem.h>
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#include <Kernel/FileSystem/FATFS/Definitions.h>
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#include <Kernel/FileSystem/Inode.h>
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#include <Kernel/Forward.h>
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#include <Kernel/Library/KBuffer.h>
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namespace Kernel {
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class DOSBIOSParameterBlock final {
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private:
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KBuffer const* const m_boot_record;
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const struct DOS4BIOSParameterBlock* m_dos4_block;
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const struct DOS7BIOSParameterBlock* m_dos7_block;
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const struct DOS3BIOSParameterBlock* m_common_block;
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public:
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DOSBIOSParameterBlock(KBuffer const* const boot_record)
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: m_boot_record(boot_record)
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, m_dos4_block(reinterpret_cast<const struct DOS4BIOSParameterBlock*>(boot_record->bytes().offset_pointer(0x024)))
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, m_dos7_block(reinterpret_cast<const struct DOS7BIOSParameterBlock*>(boot_record->bytes().offset_pointer(0x024)))
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, m_common_block(reinterpret_cast<const struct DOS3BIOSParameterBlock*>(boot_record->bytes().data()))
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{
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}
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DOSBIOSParameterBlockVersion bpb_version() const;
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DOS3BIOSParameterBlock const* common_bpb() const;
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DOS4BIOSParameterBlock const* dos4_bpb() const;
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DOS7BIOSParameterBlock const* dos7_bpb() const;
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u16 sectors_per_fat() const;
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u32 sector_count() const;
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u8 signature() const;
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};
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// Represents a block of contiguous sectors to read. This typically represents a
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// cluster, but is also used to define areas of the root directory region.
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struct FatBlockSpan {
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BlockBasedFileSystem::BlockIndex start_block;
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size_t number_of_sectors;
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};
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class FATFS final : public BlockBasedFileSystem {
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friend FATInode;
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public:
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static ErrorOr<NonnullRefPtr<FileSystem>> try_create(OpenFileDescription&, ReadonlyBytes);
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virtual ~FATFS() override = default;
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virtual StringView class_name() const override { return "FATFS"sv; }
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virtual Inode& root_inode() override;
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virtual u8 internal_file_type_to_directory_entry_type(DirectoryEntryView const& entry) const override;
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private:
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virtual ErrorOr<void> initialize_while_locked() override;
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virtual bool is_initialized_while_locked() override;
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// FIXME: This is not a proper way to clear last mount of a FAT filesystem,
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// but for now we simply have no other way to properly do it.
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virtual ErrorOr<void> prepare_to_clear_last_mount(Inode&) override { return {}; }
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FATFS(OpenFileDescription&);
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static constexpr u8 signature_1 = 0x28;
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static constexpr u8 signature_2 = 0x29;
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static constexpr u32 first_data_cluster = 2;
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FatBlockSpan first_block_of_cluster(u32 cluster) const;
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OwnPtr<KBuffer> m_boot_record;
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OwnPtr<DOSBIOSParameterBlock> m_parameter_block;
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RefPtr<FATInode> m_root_inode;
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u32 m_first_data_sector { 0 };
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FATVersion m_fat_version;
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};
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}
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