audk/MdePkg/Include/Protocol/DevicePathUtilities.h

/** @file
  EFI_DEVICE_PATH_UTILITIES_PROTOCOL as defined in UEFI 2.0.  
  Use to create and manipulate device paths and device nodes.

  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 __DEVICE_PATH_UTILITIES_PROTOCOL_H__
#define __DEVICE_PATH_UTILITIES_PROTOCOL_H__


#include <Protocol/DevicePath.h>

//
// Device Path Utilities protocol
//
#define EFI_DEVICE_PATH_UTILITIES_PROTOCOL_GUID \
  { \
    0x379be4e, 0xd706, 0x437d, {0xb0, 0x37, 0xed, 0xb8, 0x2f, 0xb7, 0x72, 0xa4 } \
  }

/**
  Returns the size of the device path, in bytes.

  @param  DevicePath Points to the start of the EFI device path.

  @retval Size       Size of the specified device path, in bytes, including the end-of-path tag.

**/
typedef
UINTN
(EFIAPI *EFI_DEVICE_PATH_UTILS_GET_DEVICE_PATH_SIZE)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
  )
;    
  

/**
  Create a duplicate of the specified path.

  @param  DevicePath Points to the source EFI device path.

  @retval Pointer    A pointer to the duplicate device path.
  @retval NULL       insufficient memory

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_UTILS_DUP_DEVICE_PATH)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
  )
;      

/**
  Create a new path by appending the second device path to the first.

  @param  Src1 Points to the first device path. If NULL, then it is ignored.
  @param  Src2 Points to the second device path. If NULL, then it is ignored.

  @retval Pointer  A pointer to the newly created device path.
  @retval NULL     Memory could not be allocated
                   or either DevicePath or DeviceNode is NULL.

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_UTILS_APPEND_PATH)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL *Src1,
  IN CONST EFI_DEVICE_PATH_PROTOCOL *Src2
  )
;     
  
/**
  Creates a new path by appending the device node to the device path.

  @param  DevicePath Points to the device path.
  @param  DeviceNode Points to the device node.

  @retval Pointer    A pointer to the allocated device node.
  @retval NULL       Memory could not be allocated
                     or either DevicePath or DeviceNode is NULL.

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_UTILS_APPEND_NODE)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode
  )
;

/**
  Creates a new path by appending the specified device path instance to the specified device path.

  @param  DevicePath         Points to the device path. If NULL, then ignored.
  @param  DevicePathInstance Points to the device path instance.

  @retval Pointer            A pointer to the newly created device path
  @retval NULL               Memory could not be allocated or DevicePathInstance is NULL.

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_UTILS_APPEND_INSTANCE)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
  IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance
  )
;  

/**
  Creates a copy of the current device path instance and returns a pointer to the next device path
  instance.

  @param  DevicePathInstance     On input, this holds the pointer to the current device path
                                 instance. On output, this holds the pointer to the next
                                 device path instance or NULL if there are no more device
                                 path instances in the device path.  
  @param  DevicePathInstanceSize On output, this holds the size of the device path instance,
                                 in bytes or zero, if DevicePathInstance is zero.

  @retval Pointer                A pointer to the copy of the current device path instance.
  @retval NULL                   DevicePathInstace was NULL on entry or there was insufficient memory.

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_UTILS_GET_NEXT_INSTANCE)(
  IN  OUT EFI_DEVICE_PATH_PROTOCOL  **DevicePathInstance,
  OUT UINTN                         *DevicePathInstanceSize
  )
;  

/**
  Creates a device node

  @param  NodeType    NodeType is the device node type (EFI_DEVICE_PATH.Type) for
                      the new device node.
  @param  NodeSubType NodeSubType is the device node sub-type
                      EFI_DEVICE_PATH.SubType) for the new device node.
  @param  NodeLength  NodeLength is the length of the device node
                      (EFI_DEVICE_PATH.Length) for the new device node.

  @retval Pointer     A pointer to the newly created device node.
  @retval NULL        NodeLength is less than
                      the size of the header or there was insufficient memory.

**/
typedef
EFI_DEVICE_PATH_PROTOCOL*
(EFIAPI *EFI_DEVICE_PATH_CREATE_NODE)(
  IN UINT8                          NodeType,
  IN UINT8                          NodeSubType,
  IN UINT16                         NodeLength
)
;   

/**
  Returns whether a device path is multi-instance.

  @param  DevicePath Points to the device path. If NULL, then ignored.

  @retval TRUE       The device path has more than one instance
  @retval FALSE      The device path is empty or contains only a single instance.

**/
typedef
BOOLEAN
(EFIAPI *EFI_DEVICE_PATH_UTILS_IS_MULTI_INSTANCE)(
  IN CONST EFI_DEVICE_PATH_PROTOCOL         *DevicePath
  )
;                                                                                                       
  
/**
  @par Protocol Description:
  This protocol is used to creates and manipulates device paths and device nodes.

  @param GetDevicePathSize 
  Returns the size of the specified device path, in bytes.

  @param DuplicateDevicePath
  Duplicates a device path structure.
 
  @param AppendDeviceNode 
  Appends the device node to the specified device path.

  @param AppendDevicePath 
  Appends the device path to the specified device path.

  @param AppendDevicePathInstance
  Appends a device path instance to another device path.

  @param GetNextDevicePathInstance
  Retrieves the next device path instance from a device path data structure.

  @param IsDevicePathMultiInstance
  Returns TRUE if this is a multi-instance device path.

  @param CreateDeviceNode 
  Allocates memory for a device node with the specified type and sub-type.
**/ 
typedef struct {
  EFI_DEVICE_PATH_UTILS_GET_DEVICE_PATH_SIZE GetDevicePathSize;
  EFI_DEVICE_PATH_UTILS_DUP_DEVICE_PATH      DuplicateDevicePath;
  EFI_DEVICE_PATH_UTILS_APPEND_PATH          AppendDevicePath;
  EFI_DEVICE_PATH_UTILS_APPEND_NODE          AppendDeviceNode;
  EFI_DEVICE_PATH_UTILS_APPEND_INSTANCE      AppendDevicePathInstance;
  EFI_DEVICE_PATH_UTILS_GET_NEXT_INSTANCE    GetNextDevicePathInstance;
  EFI_DEVICE_PATH_UTILS_IS_MULTI_INSTANCE    IsDevicePathMultiInstance;
  EFI_DEVICE_PATH_CREATE_NODE                CreateDeviceNode;
} EFI_DEVICE_PATH_UTILITIES_PROTOCOL;

extern EFI_GUID gEfiDevicePathUtilitiesProtocolGuid; 

#endif