audk/MdePkg/Include/Dxe/ArchProtocol/Bds.h

/** @file
  Boot Device Selection Architectural Protocol as defined in DXE CIS

  When the DXE core is done it calls the BDS via this protocol.

  Copyright (c) 2006, 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.             

  Module Name:  Bds.h

  @par Revision Reference:
  Version 0.91B.

**/

#ifndef __ARCH_PROTOCOL_BDS_H__
#define __ARCH_PROTOCOL_BDS_H__

//
// Global ID for the BDS Architectural Protocol
//
#define EFI_BDS_ARCH_PROTOCOL_GUID \
  { 0x665E3FF6, 0x46CC, 0x11d4, {0x9A, 0x38, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D } }

//
// Declare forward reference for the BDS Architectural Protocol
//
typedef struct _EFI_BDS_ARCH_PROTOCOL   EFI_BDS_ARCH_PROTOCOL;

/**
  This function uses policy data from the platform to determine what operating 
  system or system utility should be loaded and invoked.  This function call 
  also optionally make the use of user input to determine the operating system 
  or system utility to be loaded and invoked.  When the DXE Core has dispatched 
  all the drivers on the dispatch queue, this function is called.  This 
  function will attempt to connect the boot devices required to load and invoke 
  the selected operating system or system utility.  During this process, 
  additional firmware volumes may be discovered that may contain addition DXE 
  drivers that can be dispatched by the DXE Core.   If a boot device cannot be 
  fully connected, this function calls the DXE Service Dispatch() to allow the 
  DXE drivers from any newly discovered firmware volumes to be dispatched.  
  Then the boot device connection can be attempted again.  If the same boot 
  device connection operation fails twice in a row, then that boot device has 
  failed, and should be skipped.  This function should never return.

  @param  This             The EFI_BDS_ARCH_PROTOCOL instance.

  @return None.

**/
typedef
VOID
(EFIAPI *EFI_BDS_ENTRY) (
  IN EFI_BDS_ARCH_PROTOCOL  *This
  );

/**
  Interface stucture for the BDS Architectural Protocol.

  @par Protocol Description:
  The EFI_BDS_ARCH_PROTOCOL transfers control from DXE to an operating 
  system or a system utility.  If there are not enough drivers initialized 
  when this protocol is used to access the required boot device(s), then 
  this protocol should add drivers to the dispatch queue and return control 
  back to the dispatcher.  Once the required boot devices are available, then 
  the boot device can be used to load and invoke an OS or a system utility.

  @par Protocol Parameters:
  Entry - The entry point to BDS.  This call does not take any parameters, 
  and the return value can be ignored.  If it returns, then the 
  dispatcher must be invoked again, if it never returns, then an 
  operating system or a system utility have been invoked.

**/
struct _EFI_BDS_ARCH_PROTOCOL {
  EFI_BDS_ENTRY Entry;
};

extern EFI_GUID gEfiBdsArchProtocolGuid;

#endif