1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-14 06:54:58 +00:00
serenity/Kernel/FileSystem/FATFS/FileSystem.h

92 lines
2.9 KiB
C++

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