[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
#include "UefiDevicePathLibInternal.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
a73480f6	36	#include "UefiDevicePathLibInternal.h"\r
a73480f6	37	\r
e386b444	38	STATIC EFI_DEVICE_PATH_UTILITIES_PROTOCOL *mDevicePathUtilities = NULL;\r
	39	\r
	40	/**\r
	41	The constructor function caches the pointer to DevicePathUtilites protocol.\r
	42	\r
	43	The constructor function locates DevicePathUtilities protocol from protocol database.\r
	44	It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. \r
	45	\r
	46	@param ImageHandle The firmware allocated handle for the EFI image.\r
	47	@param SystemTable A pointer to the EFI System Table.\r
	48	\r
	49	@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.\r
	50	\r
	51	**/\r
	52	EFI_STATUS\r
	53	EFIAPI\r
	54	DevicePathLibConstructor (\r
	55	IN EFI_HANDLE ImageHandle,\r
	56	IN EFI_SYSTEM_TABLE *SystemTable\r
	57	)\r
	58	{\r
	59	EFI_STATUS Status;\r
	60	\r
	61	Status = gBS->LocateProtocol (\r
	62	&gEfiDevicePathUtilitiesProtocolGuid,\r
	63	NULL,\r
	64	(VOID**) &mDevicePathUtilities\r
	65	);\r
	66	ASSERT_EFI_ERROR (Status);\r
	67	ASSERT (mDevicePathUtilities != NULL);\r
	68	\r
	69	return Status;\r
	70	}\r
	71	\r
	72	/**\r
	73	Returns the size of a device path in bytes.\r
	74	\r
	75	This function returns the size, in bytes, of the device path data structure specified by\r
	76	DevicePath including the end of device path node. If DevicePath is NULL, then 0 is returned.\r
	77	\r
	78	@param DevicePath A pointer to a device path data structure.\r
	79	\r
	80	@return The size of a device path in bytes.\r
	81	\r
	82	**/\r
	83	UINTN\r
	84	EFIAPI\r
	85	GetDevicePathSize (\r
	86	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
	87	)\r
	88	{\r
	89	return mDevicePathUtilities->GetDevicePathSize (DevicePath);\r
	90	}\r
	91	\r
	92	/**\r
	93	Creates a new device path by appending a second device path to a first device path.\r
	94	\r
	95	This function allocates space for a new copy of the device path specified by DevicePath. If\r
	96	DevicePath is NULL, then NULL is returned. If the memory is successfully allocated, then the\r
	97	contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer\r
	98	is returned. Otherwise, NULL is returned. \r
	99	\r
	100	@param DevicePath A pointer to a device path data structure.\r
	101	\r
102	@return A pointer to the duplicated device path.\r
103	\r
104	**/\r
105	EFI_DEVICE_PATH_PROTOCOL *\r
106	EFIAPI\r
107	DuplicateDevicePath (\r
108	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
109	)\r
110	{\r
111	return mDevicePathUtilities->DuplicateDevicePath (DevicePath);\r
112	}\r
113	\r
114	/**\r
115	Creates a new device path by appending a second device path to a first device path.\r
116	\r
117	This function creates a new device path by appending a copy of SecondDevicePath to a copy of\r
118	FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from\r
119	SecondDevicePath is retained. The newly created device path is returned. \r
120	If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned. \r
121	If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned. \r
122	If both FirstDevicePath and SecondDevicePath are NULL, then NULL is returned. \r
123	If there is not enough memory for the newly allocated buffer, then NULL is returned.\r
124	The memory for the new device path is allocated from EFI boot services memory. It is the\r
125	responsibility of the caller to free the memory allocated.\r
126	\r
127	@param FirstDevicePath A pointer to a device path data structure.\r
128	@param SecondDevicePath A pointer to a device path data structure.\r
129	\r
130	@return A pointer to the new device path.\r
131	\r
132	**/\r
133	EFI_DEVICE_PATH_PROTOCOL *\r
134	EFIAPI\r
135	AppendDevicePath (\r
136	IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL\r
137	IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL\r
138	)\r
139	{\r
140	return mDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);\r
141	}\r
142	\r
143	/**\r
144	Creates a new path by appending the device node to the device path.\r
145	\r
146	This function creates a new device path by appending a copy of the device node specified by\r
147	DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.\r
148	The end-of-device-path device node is moved after the end of the appended device node.\r
149	If DevicePath is NULL, then NULL is returned.\r
150	If DevicePathNode is NULL, then NULL is returned.\r
151	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
152	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
153	free the memory allocated.\r
154	\r
155	@param DevicePath A pointer to a device path data structure.\r
156	@param DevicePathNode A pointer to a single device path node.\r
157	\r
158	@return A pointer to the new device path.\r
159	\r
160	**/\r
161	EFI_DEVICE_PATH_PROTOCOL *\r
162	EFIAPI\r
163	AppendDevicePathNode (\r
164	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
165	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL\r
166	)\r
167	{\r
168	return mDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);\r
169	}\r
170	\r
171	/**\r
172	Creates a new device path by appending the specified device path instance to the specified device\r
173	path.\r
174	\r
175	This function creates a new device path by appending a copy of the device path instance specified\r
176	by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.\r
177	The end-of-device-path device node is moved after the end of the appended device path instance\r
178	and a new end-of-device-path-instance node is inserted between. \r
179	If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r
180	If DevicePathInstance is NULL, then NULL is returned.\r
181	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
182	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
183	free the memory allocated.\r
184	\r
185	@param DevicePath A pointer to a device path data structure.\r
186	@param DevicePathInstance A pointer to a device path instance.\r
187	\r
188	@return A pointer to the new device path.\r
189	\r
190	**/\r
191	EFI_DEVICE_PATH_PROTOCOL *\r
192	EFIAPI\r
193	AppendDevicePathInstance (\r
194	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r
195	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL\r
196	)\r
197	{\r
198	return mDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);\r
199	}\r
200	\r
201	/**\r
202	Creates a copy of the current device path instance and returns a pointer to the next device path\r
203	instance.\r
204	\r
205	This function creates a copy of the current device path instance. It also updates DevicePath to\r
206	point to the next device path instance in the device path (or NULL if no more) and updates Size\r
207	to hold the size of the device path instance copy.\r
208	If DevicePath is NULL, then NULL is returned.\r
209	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
210	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
211	free the memory allocated.\r
212	If Size is NULL, then ASSERT().\r
213	\r
214	@param DevicePath On input, this holds the pointer to the current device path\r
215	instance. On output, this holds the pointer to the next device\r
216	path instance or NULL if there are no more device path\r
217	instances in the device path pointer to a device path data\r
218	structure.\r
219	@param Size On output, this holds the size of the device path instance, in\r
220	bytes or zero, if DevicePath is NULL.\r
221	\r
222	@return A pointer to the current device path instance.\r
223	\r
224	**/\r
225	EFI_DEVICE_PATH_PROTOCOL *\r
226	EFIAPI\r
227	GetNextDevicePathInstance (\r
228	IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,\r
229	OUT UINTN *Size\r
230	)\r
231	{\r
232	ASSERT (Size != NULL);\r
233	return mDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);\r
234	}\r
235	\r
236	/**\r
237	Creates a copy of the current device path instance and returns a pointer to the next device path\r
238	instance.\r
239	\r
240	This function creates a new device node in a newly allocated buffer of size NodeLength and\r
241	initializes the device path node header with NodeType and NodeSubType. The new device path node\r
242	is returned.\r
243	If NodeLength is smaller than a device path header, then NULL is returned. \r
244	If there is not enough memory to allocate space for the new device path, then NULL is returned. \r
245	The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r
246	free the memory allocated.\r
247	\r
248	@param NodeType The device node type for the new device node.\r
249	@param NodeSubType The device node sub-type for the new device node.\r
250	@param NodeLength The length of the new device node.\r
251	\r
252	@return The new device path.\r
253	\r
254	**/\r
255	EFI_DEVICE_PATH_PROTOCOL *\r
256	EFIAPI\r
257	CreateDeviceNode (\r
258	IN UINT8 NodeType,\r
259	IN UINT8 NodeSubType,\r
260	IN UINT16 NodeLength\r
261	)\r
262	{\r
263	return mDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);\r
264	}\r
265	\r
266	/**\r
267	Determines if a device path is single or multi-instance.\r
268	\r
269	This function returns TRUE if the device path specified by DevicePath is multi-instance.\r
270	Otherwise, FALSE is returned. If DevicePath is NULL, then FALSE is returned.\r
271	\r
272	@param DevicePath A pointer to a device path data structure.\r
273	\r
274	@retval TRUE DevicePath is multi-instance.\r
275	@retval FALSE DevicePath is not multi-instance or DevicePath is NULL.\r
276	\r
277	**/\r
278	BOOLEAN\r
279	EFIAPI\r
280	IsDevicePathMultiInstance (\r
281	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
282	)\r
283	{\r
284	return mDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);\r
285	}\r
286	\r
287	/**\r
288	Retrieves the device path protocol from a handle.\r
289	\r
290	This function returns the device path protocol from the handle specified by Handle. If Handle is\r
291	NULL or Handle does not contain a device path protocol, then NULL is returned.\r
292	\r
293	@param Handle The handle from which to retrieve the device path protocol.\r
294	\r
295	@return The device path protocol from the handle specified by Handle.\r
296	\r
297	**/\r
298	EFI_DEVICE_PATH_PROTOCOL *\r
299	EFIAPI\r
300	DevicePathFromHandle (\r
301	IN EFI_HANDLE Handle\r
302	)\r
303	{\r
304	EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r
305	EFI_STATUS Status;\r
306	\r
307	Status = gBS->HandleProtocol (\r
308	Handle,\r
309	&gEfiDevicePathProtocolGuid,\r
310	(VOID *) &DevicePath\r
311	);\r
312	if (EFI_ERROR (Status)) {\r
313	DevicePath = NULL;\r
314	}\r
315	return DevicePath;\r
316	}\r
317	\r
318	/**\r
319	Allocates a device path for a file and appends it to an existing device path.\r
320	\r
321	If Device is a valid device handle that contains a device path protocol, then a device path for\r
322	the file specified by FileName is allocated and appended to the device path associated with the\r
323	handle Device. The allocated device path is returned. If Device is NULL or Device is a handle\r
324	that does not support the device path protocol, then a device path containing a single device\r
325	path node for the file specified by FileName is allocated and returned.\r
326	If FileName is NULL, then ASSERT().\r
327	\r
328	@param Device A pointer to a device handle. This parameter is optional and\r
329	may be NULL.\r
330	@param FileName A pointer to a Null-terminated Unicode string.\r
331	\r
332	@return The allocated device path.\r
333	\r
334	**/\r
335	EFI_DEVICE_PATH_PROTOCOL *\r
336	EFIAPI\r
337	FileDevicePath (\r
338	IN EFI_HANDLE Device, OPTIONAL\r
339	IN CONST CHAR16 *FileName\r
340	)\r
341	{\r
342	UINTN Size;\r
343	FILEPATH_DEVICE_PATH *FilePath;\r
344	EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r
345	EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;\r
346	\r
347	DevicePath = NULL;\r
348	\r
349	Size = StrSize (FileName);\r
350	FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + EFI_END_DEVICE_PATH_LENGTH);\r
351	if (FileDevicePath != NULL) {\r
352	FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;\r
353	FilePath->Header.Type = MEDIA_DEVICE_PATH;\r
354	FilePath->Header.SubType = MEDIA_FILEPATH_DP;\r
355	CopyMem (&FilePath->PathName, FileName, Size);\r
356	SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);\r
357	SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));\r
358	\r
359	if (Device != NULL) {\r
360	DevicePath = DevicePathFromHandle (Device);\r
361	}\r
362	\r
363	DevicePath = AppendDevicePath (DevicePath, FileDevicePath);\r
364	FreePool (FileDevicePath);\r
365	}\r
366	\r
367	return DevicePath;\r
368	}\r
369	\r