uefi/linaro-edk2/MdePkg/Include/Protocol/DiskIo.h

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

  The Disk IO protocol is used to convert block oriented devices into byte
  oriented devices. The Disk IO protocol is intended to layer on top of the
  Block IO protocol.

  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials                          
  are licensed and made available under the terms and conditions of the BSD License         
  which accompanies this distribution.  The full text of the license may be found at        
  http://opensource.org/licenses/bsd-license.php                                            

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

**/

#ifndef __DISK_IO_H__
#define __DISK_IO_H__

#define EFI_DISK_IO_PROTOCOL_GUID \
  { \
    0xce345171, 0xba0b, 0x11d2, {0x8e, 0x4f, 0x0, 0xa0, 0xc9, 0x69, 0x72, 0x3b } \
  }

///
/// Protocol GUID name defined in EFI1.1.
/// 
#define DISK_IO_PROTOCOL  EFI_DISK_IO_PROTOCOL_GUID

typedef struct _EFI_DISK_IO_PROTOCOL EFI_DISK_IO_PROTOCOL;

///
/// Protocol defined in EFI1.1.
/// 
typedef EFI_DISK_IO_PROTOCOL  EFI_DISK_IO;

/**
  Read BufferSize bytes from Offset into Buffer.

  @param  This                  Protocol instance pointer.
  @param  MediaId               Id of the media, changes every time the media is replaced.
  @param  Offset                The starting byte offset to read from
  @param  BufferSize            Size of Buffer
  @param  Buffer                Buffer containing read data

  @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_CHNAGED     The MediaId does not matched the current device.
  @retval EFI_INVALID_PARAMETER The read request contains device addresses that are not
                                valid for the device.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_DISK_READ)(
  IN EFI_DISK_IO_PROTOCOL         *This,
  IN UINT32                       MediaId,
  IN UINT64                       Offset,
  IN UINTN                        BufferSize,
  OUT VOID                        *Buffer
  );

/**
  Writes a specified number of bytes to a device.

  @param  This       Indicates a pointer to the calling context.
  @param  MediaId    ID of the medium to be written.
  @param  Offset     The starting byte offset on the logical block I/O device to write.
  @param  BufferSize The size in bytes of Buffer. The number of bytes to write to the device.
  @param  Buffer     A pointer to the buffer containing the data to be written.

  @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_INVALID_PARAMETER The write request contains device addresses that are not
                                 valid for the device.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_DISK_WRITE)(
  IN EFI_DISK_IO_PROTOCOL         *This,
  IN UINT32                       MediaId,
  IN UINT64                       Offset,
  IN UINTN                        BufferSize,
  IN VOID                         *Buffer
  );

#define EFI_DISK_IO_PROTOCOL_REVISION 0x00010000

///
/// Revision defined in EFI1.1
/// 
#define EFI_DISK_IO_INTERFACE_REVISION  EFI_DISK_IO_PROTOCOL_REVISION

///
/// This protocol is used to abstract Block I/O interfaces.
///
struct _EFI_DISK_IO_PROTOCOL {
  ///
  /// The revision to which the disk I/O interface adheres. All future
  /// revisions must be backwards compatible. If a future version is not
  /// backwards compatible, it is not the same GUID.
  ///
  UINT64          Revision;
  EFI_DISK_READ   ReadDisk;
  EFI_DISK_WRITE  WriteDisk;
};

extern EFI_GUID gEfiDiskIoProtocolGuid;

#endif