BlockIo.h

Go to the documentation of this file.

/** @file
  Block IO protocol as defined in the UEFI 2.0 specification.

  The Block IO protocol is used to abstract block devices like hard drives,
  DVD-ROMs and floppy drives.

  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef __BLOCK_IO_H__
#define __BLOCK_IO_H__

FILE_LICENCE ( BSD2_PATENT );

#define EFI_BLOCK_IO_PROTOCOL_GUID \
  { \
    0x964e5b21, 0x6459, 0x11d2, {0x8e, 0x39, 0x0, 0xa0, 0xc9, 0x69, 0x72, 0x3b } \
  }

typedef struct _EFI_BLOCK_IO_PROTOCOL EFI_BLOCK_IO_PROTOCOL;

///
/// Protocol GUID name defined in EFI1.1.
///
#define BLOCK_IO_PROTOCOL  EFI_BLOCK_IO_PROTOCOL_GUID

///
/// Protocol defined in EFI1.1.
///
typedef EFI_BLOCK_IO_PROTOCOL EFI_BLOCK_IO;

/**
  Reset the Block Device.

  @param  This                 Indicates a pointer to the calling context.
  @param  ExtendedVerification Driver may perform diagnostics on reset.

  @retval EFI_SUCCESS          The device was reset.
  @retval EFI_DEVICE_ERROR     The device is not functioning properly and could
                               not be reset.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_BLOCK_RESET)(
  IN EFI_BLOCK_IO_PROTOCOL          *This,
  IN BOOLEAN                        ExtendedVerification
  );

/**
  Read BufferSize bytes from Lba into Buffer.

  @param  This       Indicates a pointer to the calling context.
  @param  MediaId    Id of the media, changes every time the media is replaced.
  @param  Lba        The starting Logical Block Address to read from
  @param  BufferSize Size of Buffer, must be a multiple of device block size.
  @param  Buffer     A pointer to the destination buffer for the data. The caller is
                     responsible for either having implicit or explicit ownership of the buffer.

  @retval EFI_SUCCESS           The data was read correctly from the device.
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the read.
  @retval EFI_NO_MEDIA          There is no media in the device.
  @retval EFI_MEDIA_CHANGED     The MediaId does not matched the current device.
  @retval EFI_BAD_BUFFER_SIZE   The Buffer was not a multiple of the block size of the device.
  @retval EFI_INVALID_PARAMETER The read request contains LBAs that are not valid,
                                or the buffer is not on proper alignment.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_BLOCK_READ)(
  IN EFI_BLOCK_IO_PROTOCOL          *This,
  IN UINT32                         MediaId,
  IN EFI_LBA                        Lba,
  IN UINTN                          BufferSize,
  OUT VOID                          *Buffer
  );

/**
  Write BufferSize bytes from Lba into Buffer.

  @param  This       Indicates a pointer to the calling context.
  @param  MediaId    The media ID that the write request is for.
  @param  Lba        The starting logical block address to be written. The caller is
                     responsible for writing to only legitimate locations.
  @param  BufferSize Size of Buffer, must be a multiple of device block size.
  @param  Buffer     A pointer to the source buffer for the data.

  @retval EFI_SUCCESS           The data was written correctly to the device.
  @retval EFI_WRITE_PROTECTED   The device can not be written to.
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write.
  @retval EFI_NO_MEDIA          There is no media in the device.
  @retval EFI_MEDIA_CHNAGED     The MediaId does not matched the current device.
  @retval EFI_BAD_BUFFER_SIZE   The Buffer was not a multiple of the block size of the device.
  @retval EFI_INVALID_PARAMETER The write request contains LBAs that are not valid,
                                or the buffer is not on proper alignment.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_BLOCK_WRITE)(
  IN EFI_BLOCK_IO_PROTOCOL          *This,
  IN UINT32                         MediaId,
  IN EFI_LBA                        Lba,
  IN UINTN                          BufferSize,
  IN VOID                           *Buffer
  );

/**
  Flush the Block Device.

  @param  This              Indicates a pointer to the calling context.

  @retval EFI_SUCCESS       All outstanding data was written to the device
  @retval EFI_DEVICE_ERROR  The device reported an error while writting back the data
  @retval EFI_NO_MEDIA      There is no media in the device.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_BLOCK_FLUSH)(
  IN EFI_BLOCK_IO_PROTOCOL  *This
  );

/**
  Block IO read only mode data and updated only via members of BlockIO
**/
typedef struct {
  ///
  /// The curent media Id. If the media changes, this value is changed.
  ///
  UINT32     MediaId;

  ///
  /// TRUE if the media is removable; otherwise, FALSE.
  ///
  BOOLEAN    RemovableMedia;

  ///
  /// TRUE if there is a media currently present in the device;
  /// othersise, FALSE. THis field shows the media present status
  /// as of the most recent ReadBlocks() or WriteBlocks() call.
  ///
  BOOLEAN    MediaPresent;

  ///
  /// TRUE if LBA 0 is the first block of a partition; otherwise
  /// FALSE. For media with only one partition this would be TRUE.
  ///
  BOOLEAN    LogicalPartition;

  ///
  /// TRUE if the media is marked read-only otherwise, FALSE.
  /// This field shows the read-only status as of the most recent WriteBlocks () call.
  ///
  BOOLEAN    ReadOnly;

  ///
  /// TRUE if the WriteBlock () function caches write data.
  ///
  BOOLEAN    WriteCaching;

  ///
  /// The intrinsic block size of the device. If the media changes, then
  /// this field is updated.
  ///
  UINT32     BlockSize;

  ///
  /// Supplies the alignment requirement for any buffer to read or write block(s).
  ///
  UINT32     IoAlign;

  ///
  /// The last logical block address on the device.
  /// If the media changes, then this field is updated.
  ///
  EFI_LBA    LastBlock;

  ///
  /// Only present if EFI_BLOCK_IO_PROTOCOL.Revision is greater than or equal to
  /// EFI_BLOCK_IO_PROTOCOL_REVISION2. Returns the first LBA is aligned to
  /// a physical block boundary.
  ///
  EFI_LBA    LowestAlignedLba;

  ///
  /// Only present if EFI_BLOCK_IO_PROTOCOL.Revision is greater than or equal to
  /// EFI_BLOCK_IO_PROTOCOL_REVISION2. Returns the number of logical blocks
  /// per physical block.
  ///
  UINT32     LogicalBlocksPerPhysicalBlock;

  ///
  /// Only present if EFI_BLOCK_IO_PROTOCOL.Revision is greater than or equal to
  /// EFI_BLOCK_IO_PROTOCOL_REVISION3. Returns the optimal transfer length
  /// granularity as a number of logical blocks.
  ///
  UINT32     OptimalTransferLengthGranularity;
} EFI_BLOCK_IO_MEDIA;

#define EFI_BLOCK_IO_PROTOCOL_REVISION   0x00010000
#define EFI_BLOCK_IO_PROTOCOL_REVISION2  0x00020001
#define EFI_BLOCK_IO_PROTOCOL_REVISION3  0x0002001F

///
/// Revision defined in EFI1.1.
///
#define EFI_BLOCK_IO_INTERFACE_REVISION  EFI_BLOCK_IO_PROTOCOL_REVISION

///
///  This protocol provides control over block devices.
///
struct _EFI_BLOCK_IO_PROTOCOL {
  ///
  /// The revision to which the block IO interface adheres. All future
  /// revisions must be backwards compatible. If a future version is not
  /// back wards compatible, it is not the same GUID.
  ///
  UINT64                Revision;
  ///
  /// Pointer to the EFI_BLOCK_IO_MEDIA data for this device.
  ///
  EFI_BLOCK_IO_MEDIA    *Media;

  EFI_BLOCK_RESET       Reset;
  EFI_BLOCK_READ        ReadBlocks;
  EFI_BLOCK_WRITE       WriteBlocks;
  EFI_BLOCK_FLUSH       FlushBlocks;
};

extern EFI_GUID  gEfiBlockIoProtocolGuid;

#endif