[mirror_edk2.git] / MdePkg / Include / Library / DevicePathLib.h

/** @file\r
  Provides library functions to construct and parse UEFI Device Paths.\r
\r
Copyright (c) 2006 - 2008, Intel Corporation\r
All rights reserved. This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#ifndef __DEVICE_PATH_LIB_H__\r
#define __DEVICE_PATH_LIB_H__\r
\r
#include <Library/BaseLib.h>\r
\r
#define END_DEVICE_PATH_LENGTH               (sizeof (EFI_DEVICE_PATH_PROTOCOL))\r
#define DevicePathNodeLength(Node)           ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0])\r
#define NextDevicePathNode(Node)             ((EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node)))\r
#define DevicePathType(Node)                 (((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type) \r
#define DevicePathSubType(Node)              (((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType)\r
#define IsDevicePathEndType(Node)            (DevicePathType (Node) == END_DEVICE_PATH_TYPE)\r
#define IsDevicePathEnd(Node)                (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE)\r
#define IsDevicePathEndInstance(Node)        (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE)\r
\r
#define SetDevicePathNodeLength(Node,NodeLength)  WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(NodeLength))\r
#define SetDevicePathEndNode(Node)  {                                   \\r
          DevicePathType (Node)    = END_DEVICE_PATH_TYPE;              \\r
          DevicePathSubType (Node) = END_ENTIRE_DEVICE_PATH_SUBTYPE;    \\r
          SetDevicePathNodeLength ((Node), END_DEVICE_PATH_LENGTH);       \\r
          }\r
\r
/**\r
  Returns the size of a device path in bytes.\r
\r
  This function returns the size, in bytes, of the device path data structure specified by\r
  DevicePath including the end of device path node.  If DevicePath is NULL, then 0 is returned.\r
\r
  @param  DevicePath                 A pointer to a device path data structure.\r
\r
  @return The size of a device path in bytes.\r
\r
**/\r
UINTN\r
EFIAPI\r
GetDevicePathSize (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath\r
  );\r
\r
/**\r
  Creates a new device path by appending a second device path to a first device path.\r
\r
  This function allocates space for a new copy of the device path specified by DevicePath.  If\r
  DevicePath is NULL, then NULL is returned.  If the memory is successfully allocated, then the\r
  contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer\r
  is returned.  Otherwise, NULL is returned.  \r
  \r
  @param  DevicePath                 A pointer to a device path data structure.\r
\r
  @return A pointer to the duplicated device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
DuplicateDevicePath (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath\r
  );\r
\r
/**\r
  Creates a new device path by appending a second device path to a first device path.\r
\r
  This function creates a new device path by appending a copy of SecondDevicePath to a copy of\r
  FirstDevicePath in a newly allocated buffer.  Only the end-of-device-path device node from\r
  SecondDevicePath is retained. The newly created device path is returned.  \r
  If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned.  \r
  If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned.  \r
  If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is\r
  returned.  \r
  If there is not enough memory for the newly allocated buffer, then NULL is returned.\r
  The memory for the new device path is allocated from EFI boot services memory. It is the\r
  responsibility of the caller to free the memory allocated.\r
\r
  @param  FirstDevicePath            A pointer to a device path data structure.\r
  @param  SecondDevicePath           A pointer to a device path data structure.\r
\r
  @return A pointer to the new device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
AppendDevicePath (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *FirstDevicePath,  OPTIONAL\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *SecondDevicePath  OPTIONAL\r
  );\r
\r
/**\r
  Creates a new path by appending the device node to the device path.\r
\r
  This function creates a new device path by appending a copy of the device node specified by\r
  DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.\r
  The end-of-device-path device node is moved after the end of the appended device node.\r
  If DevicePathNode is NULL then a copy of DevicePath is returned.\r
  If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device path device\r
  node is returned.\r
  If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path device node\r
  is returned.\r
  If there is not enough memory to allocate space for the new device path, then NULL is returned.  \r
  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
  free the memory allocated.\r
\r
  @param  DevicePath                 A pointer to a device path data structure.\r
  @param  DevicePathNode             A pointer to a single device path node.\r
\r
  @return A pointer to the new device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
AppendDevicePathNode (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,     OPTIONAL\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode  OPTIONAL\r
  );\r
\r
/**\r
  Creates a new device path by appending the specified device path instance to the specified device\r
  path.\r
 \r
  This function creates a new device path by appending a copy of the device path instance specified\r
  by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.\r
  The end-of-device-path device node is moved after the end of the appended device path instance\r
  and a new end-of-device-path-instance node is inserted between. \r
  If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r
  If DevicePathInstance is NULL, then NULL is returned.\r
  If there is not enough memory to allocate space for the new device path, then NULL is returned.  \r
  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
  free the memory allocated.\r
  \r
  @param  DevicePath                 A pointer to a device path data structure.\r
  @param  DevicePathInstance         A pointer to a device path instance.\r
\r
  @return A pointer to the new device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
AppendDevicePathInstance (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,        OPTIONAL\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathInstance OPTIONAL\r
  );\r
\r
/**\r
  Creates a copy of the current device path instance and returns a pointer to the next device path\r
  instance.\r
\r
  This function creates a copy of the current device path instance. It also updates DevicePath to\r
  point to the next device path instance in the device path (or NULL if no more) and updates Size\r
  to hold the size of the device path instance copy.\r
  If DevicePath is NULL, then NULL is returned.\r
  If there is not enough memory to allocate space for the new device path, then NULL is returned.  \r
  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
  free the memory allocated.\r
  If Size is NULL, then ASSERT().\r
 \r
  @param  DevicePath                 On input, this holds the pointer to the current device path\r
                                     instance. On output, this holds the pointer to the next device\r
                                     path instance or NULL if there are no more device path\r
                                     instances in the device path pointer to a device path data\r
                                     structure.\r
  @param  Size                       On output, this holds the size of the device path instance, in\r
                                     bytes or zero, if DevicePath is NULL.\r
\r
  @return A pointer to the current device path instance.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
GetNextDevicePathInstance (\r
  IN OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath,\r
  OUT UINTN                          *Size\r
  );\r
\r
/**\r
  Creates a copy of the current device path instance and returns a pointer to the next device path\r
  instance.\r
\r
  This function creates a new device node in a newly allocated buffer of size NodeLength and\r
  initializes the device path node header with NodeType and NodeSubType.  The new device path node\r
  is returned.\r
  If NodeLength is smaller than a device path header, then NULL is returned.  \r
  If there is not enough memory to allocate space for the new device path, then NULL is returned.  \r
  The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
  free the memory allocated.\r
\r
  @param  NodeType                   The device node type for the new device node.\r
  @param  NodeSubType                The device node sub-type for the new device node.\r
  @param  NodeLength                 The length of the new device node.\r
\r
  @return The new device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
CreateDeviceNode (\r
  IN UINT8                           NodeType,\r
  IN UINT8                           NodeSubType,\r
  IN UINT16                          NodeLength\r
  );\r
\r
/**\r
  Determines if a device path is single or multi-instance.\r
\r
  This function returns TRUE if the device path specified by DevicePath is multi-instance.\r
  Otherwise, FALSE is returned.  If DevicePath is NULL, then FALSE is returned.\r
\r
  @param  DevicePath                 A pointer to a device path data structure.\r
\r
  @retval  TRUE                      DevicePath is multi-instance.\r
  @retval  FALSE                     DevicePath is not multi-instance or DevicePath is NULL.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
IsDevicePathMultiInstance (\r
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath\r
  );\r
\r
/**\r
  Retrieves the device path protocol from a handle.\r
\r
  This function returns the device path protocol from the handle specified by Handle.  If Handle is\r
  NULL or Handle does not contain a device path protocol, then NULL is returned.\r
 \r
  @param  Handle                     The handle from which to retrieve the device path protocol.\r
\r
  @return The device path protocol from the handle specified by Handle.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
DevicePathFromHandle (\r
  IN EFI_HANDLE                      Handle\r
  );\r
\r
/**\r
  Allocates a device path for a file and appends it to an existing device path.\r
\r
  If Device is a valid device handle that contains a device path protocol, then a device path for\r
  the file specified by FileName  is allocated and appended to the device path associated with the\r
  handle Device.  The allocated device path is returned.  If Device is NULL or Device is a handle\r
  that does not support the device path protocol, then a device path containing a single device\r
  path node for the file specified by FileName is allocated and returned.\r
  If FileName is NULL, then ASSERT().\r
\r
  @param  Device                     A pointer to a device handle.  This parameter is optional and\r
                                     may be NULL.\r
  @param  FileName                   A pointer to a Null-terminated Unicode string.\r
\r
  @return The allocated device path.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
EFIAPI\r
FileDevicePath (\r
  IN EFI_HANDLE                      Device,     OPTIONAL\r
  IN CONST CHAR16                    *FileName\r
  );\r
\r
#endif\r
Commit	Line	Data
fb3df220	1	/** @file\r
50a64e5b	2	Provides library functions to construct and parse UEFI Device Paths.\r
fb3df220	3	\r
50a64e5b	4	Copyright (c) 2006 - 2008, Intel Corporation\r
	5	All rights reserved. This program and the accompanying materials\r
	6	are licensed and made available under the terms and conditions of the BSD License\r
	7	which accompanies this distribution. The full text of the license may be found at\r
	8	http://opensource.org/licenses/bsd-license.php\r
fb3df220	9	\r
50a64e5b	10	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
50a64e5b	11	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
fb3df220	12	\r
fb3df220	13	**/\r
	14	\r
	15	#ifndef __DEVICE_PATH_LIB_H__\r
	16	#define __DEVICE_PATH_LIB_H__\r
	17	\r
e5dab016	18	#include <Library/BaseLib.h>\r
	19	\r
	20	#define END_DEVICE_PATH_LENGTH (sizeof (EFI_DEVICE_PATH_PROTOCOL))\r
	21	#define DevicePathNodeLength(Node) ReadUnaligned16 ((UINT16 )&((EFI_DEVICE_PATH_PROTOCOL )(Node))->Length[0])\r
	22	#define NextDevicePathNode(Node) ((EFI_DEVICE_PATH_PROTOCOL )((UINT8 )(Node) + DevicePathNodeLength(Node)))\r
	23	#define DevicePathType(Node) (((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type) \r
	24	#define DevicePathSubType(Node) (((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType)\r
	25	#define IsDevicePathEndType(Node) (DevicePathType (Node) == END_DEVICE_PATH_TYPE)\r
	26	#define IsDevicePathEnd(Node) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE)\r
	27	#define IsDevicePathEndInstance(Node) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE)\r
	28	\r
	29	#define SetDevicePathNodeLength(Node,NodeLength) WriteUnaligned16 ((UINT16 )&((EFI_DEVICE_PATH_PROTOCOL )(Node))->Length[0], (UINT16)(NodeLength))\r
	30	#define SetDevicePathEndNode(Node) { \\r
	31	DevicePathType (Node) = END_DEVICE_PATH_TYPE; \\r
	32	DevicePathSubType (Node) = END_ENTIRE_DEVICE_PATH_SUBTYPE; \\r
	33	SetDevicePathNodeLength ((Node), END_DEVICE_PATH_LENGTH); \\r
	34	}\r
	35	\r
fb3df220	36	/**\r
	37	Returns the size of a device path in bytes.\r
	38	\r
	39	This function returns the size, in bytes, of the device path data structure specified by\r
	40	DevicePath including the end of device path node. If DevicePath is NULL, then 0 is returned.\r
	41	\r
	42	@param DevicePath A pointer to a device path data structure.\r
	43	\r
	44	@return The size of a device path in bytes.\r
	45	\r
	46	**/\r
	47	UINTN\r
	48	EFIAPI\r
	49	GetDevicePathSize (\r
	50	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
	51	);\r
	52	\r
	53	/**\r
	54	Creates a new device path by appending a second device path to a first device path.\r
	55	\r
	56	This function allocates space for a new copy of the device path specified by DevicePath. If\r
	57	DevicePath is NULL, then NULL is returned. If the memory is successfully allocated, then the\r
	58	contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer\r
	59	is returned. Otherwise, NULL is returned. \r
	60	\r
	61	@param DevicePath A pointer to a device path data structure.\r
	62	\r
	63	@return A pointer to the duplicated device path.\r
	64	\r
	65	**/\r
	66	EFI_DEVICE_PATH_PROTOCOL *\r
	67	EFIAPI\r
	68	DuplicateDevicePath (\r
	69	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
	70	);\r
	71	\r
	72	/**\r
	73	Creates a new device path by appending a second device path to a first device path.\r
	74	\r
	75	This function creates a new device path by appending a copy of SecondDevicePath to a copy of\r
	76	FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from\r
	77	SecondDevicePath is retained. The newly created device path is returned. \r
	78	If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned. \r
	79	If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned. \r
98a14db6	80	If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is\r
98a14db6	81	returned. \r
fb3df220	82	If there is not enough memory for the newly allocated buffer, then NULL is returned.\r
	83	The memory for the new device path is allocated from EFI boot services memory. It is the\r
	84	responsibility of the caller to free the memory allocated.\r
	85	\r
	86	@param FirstDevicePath A pointer to a device path data structure.\r
	87	@param SecondDevicePath A pointer to a device path data structure.\r
	88	\r
	89	@return A pointer to the new device path.\r
	90	\r
	91	**/\r
	92	EFI_DEVICE_PATH_PROTOCOL *\r
	93	EFIAPI\r
	94	AppendDevicePath (\r
	95	IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL\r
	96	IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL\r
	97	);\r
	98	\r
	99	/**\r
	100	Creates a new path by appending the device node to the device path.\r
	101	\r
	102	This function creates a new device path by appending a copy of the device node specified by\r
	103	DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.\r
	104	The end-of-device-path device node is moved after the end of the appended device node.\r
98a14db6	105	If DevicePathNode is NULL then a copy of DevicePath is returned.\r
6336a895	106	If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device path device\r
6336a895	107	node is returned.\r
98a14db6	108	If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path device node\r
98a14db6	109	is returned.\r
fb3df220	110	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
	111	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
	112	free the memory allocated.\r
	113	\r
	114	@param DevicePath A pointer to a device path data structure.\r
	115	@param DevicePathNode A pointer to a single device path node.\r
	116	\r
	117	@return A pointer to the new device path.\r
	118	\r
	119	**/\r
	120	EFI_DEVICE_PATH_PROTOCOL *\r
	121	EFIAPI\r
	122	AppendDevicePathNode (\r
	123	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
	124	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL\r
	125	);\r
	126	\r
	127	/**\r
	128	Creates a new device path by appending the specified device path instance to the specified device\r
	129	path.\r
	130	\r
	131	This function creates a new device path by appending a copy of the device path instance specified\r
	132	by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.\r
	133	The end-of-device-path device node is moved after the end of the appended device path instance\r
	134	and a new end-of-device-path-instance node is inserted between. \r
	135	If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r
	136	If DevicePathInstance is NULL, then NULL is returned.\r
	137	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
	138	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
	139	free the memory allocated.\r
	140	\r
	141	@param DevicePath A pointer to a device path data structure.\r
	142	@param DevicePathInstance A pointer to a device path instance.\r
	143	\r
	144	@return A pointer to the new device path.\r
	145	\r
	146	**/\r
	147	EFI_DEVICE_PATH_PROTOCOL *\r
	148	EFIAPI\r
	149	AppendDevicePathInstance (\r
	150	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
	151	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL\r
	152	);\r
	153	\r
	154	/**\r
	155	Creates a copy of the current device path instance and returns a pointer to the next device path\r
	156	instance.\r
	157	\r
	158	This function creates a copy of the current device path instance. It also updates DevicePath to\r
	159	point to the next device path instance in the device path (or NULL if no more) and updates Size\r
	160	to hold the size of the device path instance copy.\r
	161	If DevicePath is NULL, then NULL is returned.\r
	162	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
	163	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
	164	free the memory allocated.\r
	165	If Size is NULL, then ASSERT().\r
	166	\r
	167	@param DevicePath On input, this holds the pointer to the current device path\r
	168	instance. On output, this holds the pointer to the next device\r
	169	path instance or NULL if there are no more device path\r
	170	instances in the device path pointer to a device path data\r
	171	structure.\r
	172	@param Size On output, this holds the size of the device path instance, in\r
	173	bytes or zero, if DevicePath is NULL.\r
174	\r
175	@return A pointer to the current device path instance.\r
176	\r
177	**/\r
178	EFI_DEVICE_PATH_PROTOCOL *\r
179	EFIAPI\r
180	GetNextDevicePathInstance (\r
181	IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,\r
182	OUT UINTN *Size\r
183	);\r
184	\r
185	/**\r
186	Creates a copy of the current device path instance and returns a pointer to the next device path\r
187	instance.\r
188	\r
189	This function creates a new device node in a newly allocated buffer of size NodeLength and\r
190	initializes the device path node header with NodeType and NodeSubType. The new device path node\r
191	is returned.\r
192	If NodeLength is smaller than a device path header, then NULL is returned. \r
193	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
194	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
195	free the memory allocated.\r
196	\r
197	@param NodeType The device node type for the new device node.\r
198	@param NodeSubType The device node sub-type for the new device node.\r
199	@param NodeLength The length of the new device node.\r
200	\r
201	@return The new device path.\r
202	\r
203	**/\r
204	EFI_DEVICE_PATH_PROTOCOL *\r
205	EFIAPI\r
206	CreateDeviceNode (\r
207	IN UINT8 NodeType,\r
208	IN UINT8 NodeSubType,\r
209	IN UINT16 NodeLength\r
210	);\r
211	\r
212	/**\r
213	Determines if a device path is single or multi-instance.\r
214	\r
215	This function returns TRUE if the device path specified by DevicePath is multi-instance.\r
216	Otherwise, FALSE is returned. If DevicePath is NULL, then FALSE is returned.\r
217	\r
218	@param DevicePath A pointer to a device path data structure.\r
219	\r
220	@retval TRUE DevicePath is multi-instance.\r
221	@retval FALSE DevicePath is not multi-instance or DevicePath is NULL.\r
222	\r
223	**/\r
224	BOOLEAN\r
225	EFIAPI\r
226	IsDevicePathMultiInstance (\r
227	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
228	);\r
229	\r
230	/**\r
231	Retrieves the device path protocol from a handle.\r
232	\r
233	This function returns the device path protocol from the handle specified by Handle. If Handle is\r
234	NULL or Handle does not contain a device path protocol, then NULL is returned.\r
235	\r
236	@param Handle The handle from which to retrieve the device path protocol.\r
237	\r
238	@return The device path protocol from the handle specified by Handle.\r
239	\r
240	**/\r
241	EFI_DEVICE_PATH_PROTOCOL *\r
242	EFIAPI\r
243	DevicePathFromHandle (\r
244	IN EFI_HANDLE Handle\r
245	);\r
246	\r
247	/**\r
248	Allocates a device path for a file and appends it to an existing device path.\r
249	\r
250	If Device is a valid device handle that contains a device path protocol, then a device path for\r
251	the file specified by FileName is allocated and appended to the device path associated with the\r
252	handle Device. The allocated device path is returned. If Device is NULL or Device is a handle\r
253	that does not support the device path protocol, then a device path containing a single device\r
254	path node for the file specified by FileName is allocated and returned.\r
255	If FileName is NULL, then ASSERT().\r
256	\r
257	@param Device A pointer to a device handle. This parameter is optional and\r
258	may be NULL.\r
259	@param FileName A pointer to a Null-terminated Unicode string.\r
260	\r
261	@return The allocated device path.\r
262	\r
263	**/\r
264	EFI_DEVICE_PATH_PROTOCOL *\r
265	EFIAPI\r
266	FileDevicePath (\r
267	IN EFI_HANDLE Device, OPTIONAL\r
268	IN CONST CHAR16 *FileName\r
269	);\r
270	\r
271	#endif\r