[mirror_edk2.git] / MdePkg / Library / UefiDevicePathLibDevicePathProtocol / UefiDevicePathLib.c

/** @file\r
  UEFI Device Path Library.\r
\r
  Copyright (c) 2006, Intel Corporation<BR>\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
  Module Name:  UefiDevicePathLib.c\r
\r
**/\r
\r
//\r
// The package level header files this module uses\r
//\r
#include <Uefi.h>\r
//\r
// The protocols, PPI and GUID defintions for this module\r
//\r
#include <Protocol/DevicePathUtilities.h>\r
#include <Protocol/DevicePath.h>\r
//\r
// The Library classes this module consumes\r
//\r
#include <Library/DevicePathLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/BaseLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
STATIC EFI_DEVICE_PATH_UTILITIES_PROTOCOL          *mDevicePathUtilities = NULL;\r
\r
/**\r
  The constructor function caches the pointer to DevicePathUtilites protocol.\r
  \r
  The constructor function locates DevicePathUtilities protocol from protocol database.\r
  It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. \r
\r
  @param  ImageHandle   The firmware allocated handle for the EFI image.\r
  @param  SystemTable   A pointer to the EFI System Table.\r
  \r
  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DevicePathLibConstructor (\r
  IN      EFI_HANDLE                ImageHandle,\r
  IN      EFI_SYSTEM_TABLE          *SystemTable\r
  )\r
{\r
  EFI_STATUS                        Status;\r
\r
  Status = gBS->LocateProtocol (\r
                  &gEfiDevicePathUtilitiesProtocolGuid,\r
                  NULL,\r
                  (VOID**) &mDevicePathUtilities\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
  ASSERT (mDevicePathUtilities != NULL);\r
\r
  return Status;\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
  return mDevicePathUtilities->GetDevicePathSize (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
  return mDevicePathUtilities->DuplicateDevicePath (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 NULL is 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
  return mDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);\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 DevicePath is NULL, then NULL is returned.\r
  If DevicePathNode 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  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
  return mDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);\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
  return mDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);\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
  ASSERT (Size != NULL);\r
  return mDevicePathUtilities->GetNextDevicePathInstance (DevicePath, 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
  return mDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, 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
  return mDevicePathUtilities->IsDevicePathMultiInstance (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
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;\r
  EFI_STATUS                Status;\r
\r
  Status = gBS->HandleProtocol (\r
                  Handle,\r
                  &gEfiDevicePathProtocolGuid,\r
                  (VOID *) &DevicePath\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    DevicePath = NULL;\r
  }\r
  return DevicePath;\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
  UINTN                     Size;\r
  FILEPATH_DEVICE_PATH      *FilePath;\r
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;\r
  EFI_DEVICE_PATH_PROTOCOL  *FileDevicePath;\r
\r
  DevicePath = NULL;\r
\r
  Size = StrSize (FileName);\r
  FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + EFI_END_DEVICE_PATH_LENGTH);\r
  if (FileDevicePath != NULL) {\r
    FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;\r
    FilePath->Header.Type    = MEDIA_DEVICE_PATH;\r
    FilePath->Header.SubType = MEDIA_FILEPATH_DP;\r
    CopyMem (&FilePath->PathName, FileName, Size);\r
    SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);\r
    SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));\r
\r
    if (Device != NULL) {\r
      DevicePath = DevicePathFromHandle (Device);\r
    }\r
\r
    DevicePath = AppendDevicePath (DevicePath, FileDevicePath);\r
    FreePool (FileDevicePath);\r
  }\r
\r
  return DevicePath;\r
}\r
\r
Commit	Line	Data
e386b444	1	/** @file\r
	2	UEFI Device Path Library.\r
	3	\r
	4	Copyright (c) 2006, Intel Corporation<BR>\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
	9	\r
	10	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	11	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	12	\r
	13	Module Name: UefiDevicePathLib.c\r
	14	\r
	15	**/\r
	16	\r
	17	//\r
c7d265a9	18	// The package level header files this module uses\r
e386b444	19	//\r
c7d265a9	20	#include <Uefi.h>\r
	21	//\r
	22	// The protocols, PPI and GUID defintions for this module\r
	23	//\r
	24	#include <Protocol/DevicePathUtilities.h>\r
	25	#include <Protocol/DevicePath.h>\r
	26	//\r
	27	// The Library classes this module consumes\r
	28	//\r
	29	#include <Library/DevicePathLib.h>\r
	30	#include <Library/DebugLib.h>\r
	31	#include <Library/BaseLib.h>\r
	32	#include <Library/MemoryAllocationLib.h>\r
	33	#include <Library/BaseMemoryLib.h>\r
	34	#include <Library/UefiBootServicesTableLib.h>\r
e386b444	35	\r
	36	STATIC EFI_DEVICE_PATH_UTILITIES_PROTOCOL *mDevicePathUtilities = NULL;\r
	37	\r
	38	/**\r
	39	The constructor function caches the pointer to DevicePathUtilites protocol.\r
	40	\r
	41	The constructor function locates DevicePathUtilities protocol from protocol database.\r
	42	It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. \r
	43	\r
	44	@param ImageHandle The firmware allocated handle for the EFI image.\r
	45	@param SystemTable A pointer to the EFI System Table.\r
	46	\r
	47	@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.\r
	48	\r
	49	**/\r
	50	EFI_STATUS\r
	51	EFIAPI\r
	52	DevicePathLibConstructor (\r
	53	IN EFI_HANDLE ImageHandle,\r
	54	IN EFI_SYSTEM_TABLE *SystemTable\r
	55	)\r
	56	{\r
	57	EFI_STATUS Status;\r
	58	\r
	59	Status = gBS->LocateProtocol (\r
	60	&gEfiDevicePathUtilitiesProtocolGuid,\r
	61	NULL,\r
	62	(VOID**) &mDevicePathUtilities\r
	63	);\r
	64	ASSERT_EFI_ERROR (Status);\r
	65	ASSERT (mDevicePathUtilities != NULL);\r
	66	\r
	67	return Status;\r
	68	}\r
	69	\r
	70	/**\r
	71	Returns the size of a device path in bytes.\r
	72	\r
	73	This function returns the size, in bytes, of the device path data structure specified by\r
	74	DevicePath including the end of device path node. If DevicePath is NULL, then 0 is returned.\r
	75	\r
	76	@param DevicePath A pointer to a device path data structure.\r
	77	\r
	78	@return The size of a device path in bytes.\r
	79	\r
	80	**/\r
	81	UINTN\r
	82	EFIAPI\r
	83	GetDevicePathSize (\r
	84	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
	85	)\r
	86	{\r
	87	return mDevicePathUtilities->GetDevicePathSize (DevicePath);\r
	88	}\r
	89	\r
	90	/**\r
	91	Creates a new device path by appending a second device path to a first device path.\r
	92	\r
	93	This function allocates space for a new copy of the device path specified by DevicePath. If\r
	94	DevicePath is NULL, then NULL is returned. If the memory is successfully allocated, then the\r
	95	contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer\r
	96	is returned. Otherwise, NULL is returned. \r
	97	\r
	98	@param DevicePath A pointer to a device path data structure.\r
99	\r
100	@return A pointer to the duplicated device path.\r
101	\r
102	**/\r
103	EFI_DEVICE_PATH_PROTOCOL *\r
104	EFIAPI\r
105	DuplicateDevicePath (\r
106	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
107	)\r
108	{\r
109	return mDevicePathUtilities->DuplicateDevicePath (DevicePath);\r
110	}\r
111	\r
112	/**\r
113	Creates a new device path by appending a second device path to a first device path.\r
114	\r
115	This function creates a new device path by appending a copy of SecondDevicePath to a copy of\r
116	FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from\r
117	SecondDevicePath is retained. The newly created device path is returned. \r
118	If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned. \r
119	If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned. \r
120	If both FirstDevicePath and SecondDevicePath are NULL, then NULL is returned. \r
121	If there is not enough memory for the newly allocated buffer, then NULL is returned.\r
122	The memory for the new device path is allocated from EFI boot services memory. It is the\r
123	responsibility of the caller to free the memory allocated.\r
124	\r
125	@param FirstDevicePath A pointer to a device path data structure.\r
126	@param SecondDevicePath A pointer to a device path data structure.\r
127	\r
128	@return A pointer to the new device path.\r
129	\r
130	**/\r
131	EFI_DEVICE_PATH_PROTOCOL *\r
132	EFIAPI\r
133	AppendDevicePath (\r
134	IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL\r
135	IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL\r
136	)\r
137	{\r
138	return mDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);\r
139	}\r
140	\r
141	/**\r
142	Creates a new path by appending the device node to the device path.\r
143	\r
144	This function creates a new device path by appending a copy of the device node specified by\r
145	DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.\r
146	The end-of-device-path device node is moved after the end of the appended device node.\r
147	If DevicePath is NULL, then NULL is returned.\r
148	If DevicePathNode is NULL, then NULL is returned.\r
149	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
150	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
151	free the memory allocated.\r
152	\r
153	@param DevicePath A pointer to a device path data structure.\r
154	@param DevicePathNode A pointer to a single device path node.\r
155	\r
156	@return A pointer to the new device path.\r
157	\r
158	**/\r
159	EFI_DEVICE_PATH_PROTOCOL *\r
160	EFIAPI\r
161	AppendDevicePathNode (\r
162	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
163	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL\r
164	)\r
165	{\r
166	return mDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);\r
167	}\r
168	\r
169	/**\r
170	Creates a new device path by appending the specified device path instance to the specified device\r
171	path.\r
172	\r
173	This function creates a new device path by appending a copy of the device path instance specified\r
174	by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.\r
175	The end-of-device-path device node is moved after the end of the appended device path instance\r
176	and a new end-of-device-path-instance node is inserted between. \r
177	If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r
178	If DevicePathInstance is NULL, then NULL is returned.\r
179	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
180	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
181	free the memory allocated.\r
182	\r
183	@param DevicePath A pointer to a device path data structure.\r
184	@param DevicePathInstance A pointer to a device path instance.\r
185	\r
186	@return A pointer to the new device path.\r
187	\r
188	**/\r
189	EFI_DEVICE_PATH_PROTOCOL *\r
190	EFIAPI\r
191	AppendDevicePathInstance (\r
192	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
193	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL\r
194	)\r
195	{\r
196	return mDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);\r
197	}\r
198	\r
199	/**\r
200	Creates a copy of the current device path instance and returns a pointer to the next device path\r
201	instance.\r
202	\r
203	This function creates a copy of the current device path instance. It also updates DevicePath to\r
204	point to the next device path instance in the device path (or NULL if no more) and updates Size\r
205	to hold the size of the device path instance copy.\r
206	If DevicePath is NULL, then NULL is returned.\r
207	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
208	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
209	free the memory allocated.\r
210	If Size is NULL, then ASSERT().\r
211	\r
212	@param DevicePath On input, this holds the pointer to the current device path\r
213	instance. On output, this holds the pointer to the next device\r
214	path instance or NULL if there are no more device path\r
215	instances in the device path pointer to a device path data\r
216	structure.\r
217	@param Size On output, this holds the size of the device path instance, in\r
218	bytes or zero, if DevicePath is NULL.\r
219	\r
220	@return A pointer to the current device path instance.\r
221	\r
222	**/\r
223	EFI_DEVICE_PATH_PROTOCOL *\r
224	EFIAPI\r
225	GetNextDevicePathInstance (\r
226	IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,\r
227	OUT UINTN *Size\r
228	)\r
229	{\r
230	ASSERT (Size != NULL);\r
231	return mDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);\r
232	}\r
233	\r
234	/**\r
235	Creates a copy of the current device path instance and returns a pointer to the next device path\r
236	instance.\r
237	\r
238	This function creates a new device node in a newly allocated buffer of size NodeLength and\r
239	initializes the device path node header with NodeType and NodeSubType. The new device path node\r
240	is returned.\r
241	If NodeLength is smaller than a device path header, then NULL is returned. \r
242	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
243	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
244	free the memory allocated.\r
245	\r
246	@param NodeType The device node type for the new device node.\r
247	@param NodeSubType The device node sub-type for the new device node.\r
248	@param NodeLength The length of the new device node.\r
249	\r
250	@return The new device path.\r
251	\r
252	**/\r
253	EFI_DEVICE_PATH_PROTOCOL *\r
254	EFIAPI\r
255	CreateDeviceNode (\r
256	IN UINT8 NodeType,\r
257	IN UINT8 NodeSubType,\r
258	IN UINT16 NodeLength\r
259	)\r
260	{\r
261	return mDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);\r
262	}\r
263	\r
264	/**\r
265	Determines if a device path is single or multi-instance.\r
266	\r
267	This function returns TRUE if the device path specified by DevicePath is multi-instance.\r
268	Otherwise, FALSE is returned. If DevicePath is NULL, then FALSE is returned.\r
269	\r
270	@param DevicePath A pointer to a device path data structure.\r
271	\r
272	@retval TRUE DevicePath is multi-instance.\r
273	@retval FALSE DevicePath is not multi-instance or DevicePath is NULL.\r
274	\r
275	**/\r
276	BOOLEAN\r
277	EFIAPI\r
278	IsDevicePathMultiInstance (\r
279	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
280	)\r
281	{\r
282	return mDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);\r
283	}\r
284	\r
285	/**\r
286	Retrieves the device path protocol from a handle.\r
287	\r
288	This function returns the device path protocol from the handle specified by Handle. If Handle is\r
289	NULL or Handle does not contain a device path protocol, then NULL is returned.\r
290	\r
291	@param Handle The handle from which to retrieve the device path protocol.\r
292	\r
293	@return The device path protocol from the handle specified by Handle.\r
294	\r
295	**/\r
296	EFI_DEVICE_PATH_PROTOCOL *\r
297	EFIAPI\r
298	DevicePathFromHandle (\r
299	IN EFI_HANDLE Handle\r
300	)\r
301	{\r
302	EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r
303	EFI_STATUS Status;\r
304	\r
305	Status = gBS->HandleProtocol (\r
306	Handle,\r
307	&gEfiDevicePathProtocolGuid,\r
308	(VOID *) &DevicePath\r
309	);\r
310	if (EFI_ERROR (Status)) {\r
311	DevicePath = NULL;\r
312	}\r
313	return DevicePath;\r
314	}\r
315	\r
316	/**\r
317	Allocates a device path for a file and appends it to an existing device path.\r
318	\r
319	If Device is a valid device handle that contains a device path protocol, then a device path for\r
320	the file specified by FileName is allocated and appended to the device path associated with the\r
321	handle Device. The allocated device path is returned. If Device is NULL or Device is a handle\r
322	that does not support the device path protocol, then a device path containing a single device\r
323	path node for the file specified by FileName is allocated and returned.\r
324	If FileName is NULL, then ASSERT().\r
325	\r
326	@param Device A pointer to a device handle. This parameter is optional and\r
327	may be NULL.\r
328	@param FileName A pointer to a Null-terminated Unicode string.\r
329	\r
330	@return The allocated device path.\r
331	\r
332	**/\r
333	EFI_DEVICE_PATH_PROTOCOL *\r
334	EFIAPI\r
335	FileDevicePath (\r
336	IN EFI_HANDLE Device, OPTIONAL\r
337	IN CONST CHAR16 *FileName\r
338	)\r
339	{\r
340	UINTN Size;\r
341	FILEPATH_DEVICE_PATH *FilePath;\r
342	EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r
343	EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;\r
344	\r
345	DevicePath = NULL;\r
346	\r
347	Size = StrSize (FileName);\r
348	FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + EFI_END_DEVICE_PATH_LENGTH);\r
349	if (FileDevicePath != NULL) {\r
350	FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;\r
351	FilePath->Header.Type = MEDIA_DEVICE_PATH;\r
352	FilePath->Header.SubType = MEDIA_FILEPATH_DP;\r
353	CopyMem (&FilePath->PathName, FileName, Size);\r
354	SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);\r
355	SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));\r
356	\r
357	if (Device != NULL) {\r
358	DevicePath = DevicePathFromHandle (Device);\r
359	}\r
360	\r
361	DevicePath = AppendDevicePath (DevicePath, FileDevicePath);\r
362	FreePool (FileDevicePath);\r
363	}\r
364	\r
365	return DevicePath;\r
366	}\r
367	\r