/** @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 - 2008, Intel Corporation                                                         
  All rights reserved. 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 __BLOCK_IO_H__
#define __BLOCK_IO_H__

#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                 Protocol instance pointer.
  @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       Protocol instance pointer.
  @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     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_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 device addresses that are not
                                valid for the device.

**/
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       Protocol instance pointer.
  @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     Buffer containing read 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 a LBA that is not
                                valid for the device.

**/
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              Protocol instance pointer.

  @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
  
  @param MediaId
  The curent media Id. If the media changes, this value is changed.
  
  @param RemovableMedia
  TRUE if the media is removable; otherwise, FALSE.
  
  @param MediaPresent
  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.

  @param LogicalPartition
  TRUE if LBA 0 is the first block of a partition; otherwise
  FALSE. For media with only one partition this would be TRUE.
  
  @param ReadOnly
  TRUE if the media is marked read-only otherwise, FALSE.
  This field shows the read-only status as of the most recent WriteBlocks () call.
  
  @param WriteCaching
  TRUE if the WriteBlock () function caches write data.

  @param BlockSize
  The intrinsic block size of the device. If the media changes, then
  this field is updated.  

  @param IoAlign
  Supplies the alignment requirement for any buffer to read or write block(s).
  
  @param LastBlock
  The last logical block address on the device.
  If the media changes, then this field is updated.   

**/
typedef struct {
  UINT32  MediaId;    
  BOOLEAN RemovableMedia;
  BOOLEAN MediaPresent;
  BOOLEAN LogicalPartition;
  BOOLEAN ReadOnly;
  BOOLEAN WriteCaching; 
  UINT32  BlockSize; 
  UINT32  IoAlign; 
  EFI_LBA LastBlock; 
} EFI_BLOCK_IO_MEDIA;

#define EFI_BLOCK_IO_PROTOCOL_REVISION  0x00010000
//
// Revision defined in EFI1.1.
// 
#define EFI_BLOCK_IO_INTERFACE_REVISION   EFI_BLOCK_IO_PROTOCOL_REVISION

/**
  @par Protocol Description:
  This protocol provides control over block devices.

  @param Revision 
  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.
  
  @param Media 
  A pointer to the EFI_BLOCK_IO_MEDIA data for this device.

  @param Reset 
  Resets the block device hardware.

  @param ReadBlocks 
  Reads the requested number of blocks from the device. 

  @param WriteBlocks 
  Writes the requested number of blocks to the device. 

  @param FlushBlocks 
  Flushes and cache blocks. This function is optional and only
  needs to be supported on block devices that cache writes. 
**/
struct _EFI_BLOCK_IO_PROTOCOL {
  UINT64              Revision;

  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