git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@3916 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			366 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			366 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/** @file
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  UEFI Device Path Library.
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  Copyright (c) 2006, Intel Corporation<BR>
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  All rights reserved. This program and the accompanying materials
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  are licensed and made available under the terms and conditions of the BSD License
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  which accompanies this distribution.  The full text of the license may be found at
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  http://opensource.org/licenses/bsd-license.php
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  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include <Uefi.h>
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#include <Protocol/DevicePathUtilities.h>
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#include <Protocol/DevicePath.h>
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#include <Library/DevicePathLib.h>
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#include <Library/DebugLib.h>
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#include <Library/BaseLib.h>
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#include <Library/MemoryAllocationLib.h>
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#include <Library/BaseMemoryLib.h>
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#include <Library/UefiBootServicesTableLib.h>
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#include "UefiDevicePathLibInternal.h"
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STATIC EFI_DEVICE_PATH_UTILITIES_PROTOCOL          *mDevicePathUtilities = NULL;
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/**
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  The constructor function caches the pointer to DevicePathUtilites protocol.
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  The constructor function locates DevicePathUtilities protocol from protocol database.
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  It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. 
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  @param  ImageHandle   The firmware allocated handle for the EFI image.
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  @param  SystemTable   A pointer to the EFI System Table.
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  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
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**/
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EFI_STATUS
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EFIAPI
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DevicePathLibConstructor (
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  IN      EFI_HANDLE                ImageHandle,
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  IN      EFI_SYSTEM_TABLE          *SystemTable
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  )
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{
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  EFI_STATUS                        Status;
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  Status = gBS->LocateProtocol (
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                  &gEfiDevicePathUtilitiesProtocolGuid,
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                  NULL,
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                  (VOID**) &mDevicePathUtilities
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                  );
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  ASSERT_EFI_ERROR (Status);
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  ASSERT (mDevicePathUtilities != NULL);
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  return Status;
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}
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/**
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  Returns the size of a device path in bytes.
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  This function returns the size, in bytes, of the device path data structure specified by
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  DevicePath including the end of device path node.  If DevicePath is NULL, then 0 is returned.
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  @param  DevicePath                 A pointer to a device path data structure.
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  @return The size of a device path in bytes.
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**/
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UINTN
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EFIAPI
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GetDevicePathSize (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
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  )
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{
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  return mDevicePathUtilities->GetDevicePathSize (DevicePath);
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}
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/**
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  Creates a new device path by appending a second device path to a first device path.
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  This function allocates space for a new copy of the device path specified by DevicePath.  If
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  DevicePath is NULL, then NULL is returned.  If the memory is successfully allocated, then the
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  contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer
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  is returned.  Otherwise, NULL is returned.  
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  @param  DevicePath                 A pointer to a device path data structure.
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  @return A pointer to the duplicated device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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DuplicateDevicePath (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
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  )
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{
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  return mDevicePathUtilities->DuplicateDevicePath (DevicePath);
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}
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/**
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  Creates a new device path by appending a second device path to a first device path.
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  This function creates a new device path by appending a copy of SecondDevicePath to a copy of
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  FirstDevicePath in a newly allocated buffer.  Only the end-of-device-path device node from
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  SecondDevicePath is retained. The newly created device path is returned.  
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  If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned.  
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  If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned.  
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  If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is
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  returned.  
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  If there is not enough memory for the newly allocated buffer, then NULL is returned.
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  The memory for the new device path is allocated from EFI boot services memory. It is the
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  responsibility of the caller to free the memory allocated.
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  @param  FirstDevicePath            A pointer to a device path data structure.
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  @param  SecondDevicePath           A pointer to a device path data structure.
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  @return A pointer to the new device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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AppendDevicePath (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *FirstDevicePath,  OPTIONAL
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *SecondDevicePath  OPTIONAL
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  )
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{
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  return mDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);
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}
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/**
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  Creates a new path by appending the device node to the device path.
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  This function creates a new device path by appending a copy of the device node specified by
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  DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.
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  The end-of-device-path device node is moved after the end of the appended device node.
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  If DevicePathNode is NULL then a copy of DevicePath is returned.
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  If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device path device
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  node is returned.
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  If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path device node
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  is returned.
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  If there is not enough memory to allocate space for the new device path, then NULL is returned.  
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  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
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  free the memory allocated.
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  @param  DevicePath                 A pointer to a device path data structure.
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  @param  DevicePathNode             A pointer to a single device path node.
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  @return A pointer to the new device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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AppendDevicePathNode (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,     OPTIONAL
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode  OPTIONAL
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  )
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{
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  return mDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);
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}
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/**
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  Creates a new device path by appending the specified device path instance to the specified device
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  path.
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  This function creates a new device path by appending a copy of the device path instance specified
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  by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.
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  The end-of-device-path device node is moved after the end of the appended device path instance
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  and a new end-of-device-path-instance node is inserted between. 
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  If DevicePath is NULL, then a copy if DevicePathInstance is returned.
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  If DevicePathInstance is NULL, then NULL is returned.
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  If there is not enough memory to allocate space for the new device path, then NULL is returned.  
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  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
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  free the memory allocated.
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  @param  DevicePath                 A pointer to a device path data structure.
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  @param  DevicePathInstance         A pointer to a device path instance.
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  @return A pointer to the new device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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AppendDevicePathInstance (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,        OPTIONAL
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathInstance OPTIONAL
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  )
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{
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  return mDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);
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}
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/**
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  Creates a copy of the current device path instance and returns a pointer to the next device path
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  instance.
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  This function creates a copy of the current device path instance. It also updates DevicePath to
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  point to the next device path instance in the device path (or NULL if no more) and updates Size
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  to hold the size of the device path instance copy.
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  If DevicePath is NULL, then NULL is returned.
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  If there is not enough memory to allocate space for the new device path, then NULL is returned.  
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  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
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  free the memory allocated.
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  If Size is NULL, then ASSERT().
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  @param  DevicePath                 On input, this holds the pointer to the current device path
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                                     instance. On output, this holds the pointer to the next device
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                                     path instance or NULL if there are no more device path
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                                     instances in the device path pointer to a device path data
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                                     structure.
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  @param  Size                       On output, this holds the size of the device path instance, in
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                                     bytes or zero, if DevicePath is NULL.
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  @return A pointer to the current device path instance.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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GetNextDevicePathInstance (
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  IN OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath,
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  OUT UINTN                          *Size
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  )
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{
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  ASSERT (Size != NULL);
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  return mDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);
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}
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/**
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  Creates a copy of the current device path instance and returns a pointer to the next device path
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  instance.
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  This function creates a new device node in a newly allocated buffer of size NodeLength and
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  initializes the device path node header with NodeType and NodeSubType.  The new device path node
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  is returned.
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  If NodeLength is smaller than a device path header, then NULL is returned.  
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  If there is not enough memory to allocate space for the new device path, then NULL is returned.  
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  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
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  free the memory allocated.
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  @param  NodeType                   The device node type for the new device node.
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  @param  NodeSubType                The device node sub-type for the new device node.
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  @param  NodeLength                 The length of the new device node.
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  @return The new device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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CreateDeviceNode (
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  IN UINT8                           NodeType,
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  IN UINT8                           NodeSubType,
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  IN UINT16                          NodeLength
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  )
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{
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  return mDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);
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}
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/**
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  Determines if a device path is single or multi-instance.
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  This function returns TRUE if the device path specified by DevicePath is multi-instance.
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  Otherwise, FALSE is returned.  If DevicePath is NULL, then FALSE is returned.
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  @param  DevicePath                 A pointer to a device path data structure.
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  @retval  TRUE                      DevicePath is multi-instance.
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  @retval  FALSE                     DevicePath is not multi-instance or DevicePath is NULL.
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**/
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BOOLEAN
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EFIAPI
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IsDevicePathMultiInstance (
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  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
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  )
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{
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  return mDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);
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}
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/**
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  Retrieves the device path protocol from a handle.
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  This function returns the device path protocol from the handle specified by Handle.  If Handle is
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  NULL or Handle does not contain a device path protocol, then NULL is returned.
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  @param  Handle                     The handle from which to retrieve the device path protocol.
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  @return The device path protocol from the handle specified by Handle.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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DevicePathFromHandle (
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  IN EFI_HANDLE                      Handle
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  )
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{
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  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
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  EFI_STATUS                Status;
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  Status = gBS->HandleProtocol (
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                  Handle,
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                  &gEfiDevicePathProtocolGuid,
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                  (VOID *) &DevicePath
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                  );
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  if (EFI_ERROR (Status)) {
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    DevicePath = NULL;
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  }
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  return DevicePath;
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}
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/**
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  Allocates a device path for a file and appends it to an existing device path.
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  If Device is a valid device handle that contains a device path protocol, then a device path for
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  the file specified by FileName  is allocated and appended to the device path associated with the
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  handle Device.  The allocated device path is returned.  If Device is NULL or Device is a handle
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  that does not support the device path protocol, then a device path containing a single device
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  path node for the file specified by FileName is allocated and returned.
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  If FileName is NULL, then ASSERT().
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  @param  Device                     A pointer to a device handle.  This parameter is optional and
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                                     may be NULL.
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  @param  FileName                   A pointer to a Null-terminated Unicode string.
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  @return The allocated device path.
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**/
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EFI_DEVICE_PATH_PROTOCOL *
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EFIAPI
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FileDevicePath (
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  IN EFI_HANDLE                      Device,     OPTIONAL
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  IN CONST CHAR16                    *FileName
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  )
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{
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  UINTN                     Size;
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  FILEPATH_DEVICE_PATH      *FilePath;
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  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
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  EFI_DEVICE_PATH_PROTOCOL  *FileDevicePath;
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  DevicePath = NULL;
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  Size = StrSize (FileName);
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  FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + EFI_END_DEVICE_PATH_LENGTH);
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  if (FileDevicePath != NULL) {
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    FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;
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    FilePath->Header.Type    = MEDIA_DEVICE_PATH;
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    FilePath->Header.SubType = MEDIA_FILEPATH_DP;
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    CopyMem (&FilePath->PathName, FileName, Size);
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    SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);
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    SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));
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    if (Device != NULL) {
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      DevicePath = DevicePathFromHandle (Device);
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    }
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    DevicePath = AppendDevicePath (DevicePath, FileDevicePath);
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    FreePool (FileDevicePath);
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  }
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  return DevicePath;
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}
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