[mirror_edk2.git] / IntelFrameworkModulePkg / Universal / BdsDxe / BootMaint / BmLib.c

/** @file\r
  Utility routines used by boot maintenance modules.\r
\r
Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.<BR>\r
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
#include "BootMaint.h"\r
\r
/**\r
\r
  Function opens and returns a file handle to the root directory of a volume.\r
\r
  @param DeviceHandle    A handle for a device\r
\r
  @return A valid file handle or NULL is returned\r
\r
**/\r
EFI_FILE_HANDLE\r
EfiLibOpenRoot (\r
  IN EFI_HANDLE                   DeviceHandle\r
  )\r
{\r
  EFI_STATUS                      Status;\r
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Volume;\r
  EFI_FILE_HANDLE                 File;\r
\r
  File = NULL;\r
\r
  //\r
  // File the file system interface to the device\r
  //\r
  Status = gBS->HandleProtocol (\r
                  DeviceHandle,\r
                  &gEfiSimpleFileSystemProtocolGuid,\r
                  (VOID *) &Volume\r
                  );\r
\r
  //\r
  // Open the root directory of the volume\r
  //\r
  if (!EFI_ERROR (Status)) {\r
    Status = Volume->OpenVolume (\r
                      Volume,\r
                      &File\r
                      );\r
  }\r
  //\r
  // Done\r
  //\r
  return EFI_ERROR (Status) ? NULL : File;\r
}\r
\r
/**\r
\r
  Helper function called as part of the code needed\r
  to allocate the proper sized buffer for various\r
  EFI interfaces.\r
\r
\r
  @param Status          Current status\r
  @param Buffer          Current allocated buffer, or NULL\r
  @param BufferSize      Current buffer size needed\r
\r
  @retval  TRUE  if the buffer was reallocated and the caller\r
                 should try the API again.\r
  @retval  FALSE The caller should not call this function again.\r
\r
**/\r
BOOLEAN\r
EfiGrowBuffer (\r
  IN OUT EFI_STATUS   *Status,\r
  IN OUT VOID         **Buffer,\r
  IN UINTN            BufferSize\r
  )\r
{\r
  BOOLEAN TryAgain;\r
\r
  //\r
  // If this is an initial request, buffer will be null with a new buffer size\r
  //\r
  if ((*Buffer == NULL) && (BufferSize != 0)) {\r
    *Status = EFI_BUFFER_TOO_SMALL;\r
  }\r
  //\r
  // If the status code is "buffer too small", resize the buffer\r
  //\r
  TryAgain = FALSE;\r
  if (*Status == EFI_BUFFER_TOO_SMALL) {\r
\r
    if (*Buffer != NULL) {\r
      FreePool (*Buffer);\r
    }\r
\r
    *Buffer = AllocateZeroPool (BufferSize);\r
\r
    if (*Buffer != NULL) {\r
      TryAgain = TRUE;\r
    } else {\r
      *Status = EFI_OUT_OF_RESOURCES;\r
    }\r
  }\r
  //\r
  // If there's an error, free the buffer\r
  //\r
  if (!TryAgain && EFI_ERROR (*Status) && (*Buffer != NULL)) {\r
    FreePool (*Buffer);\r
    *Buffer = NULL;\r
  }\r
\r
  return TryAgain;\r
}\r
\r
/**\r
  Function returns the value of the specified variable.\r
\r
\r
  @param Name            A Null-terminated Unicode string that is\r
                         the name of the vendor's variable.\r
  @param VendorGuid      A unique identifier for the vendor.\r
\r
  @return               The payload of the variable.\r
  @retval NULL          If the variable can't be read.\r
\r
**/\r
VOID *\r
EfiLibGetVariable (\r
  IN CHAR16               *Name,\r
  IN EFI_GUID             *VendorGuid\r
  )\r
{\r
  UINTN VarSize;\r
\r
  return BdsLibGetVariableAndSize (Name, VendorGuid, &VarSize);\r
}\r
\r
/**\r
  Function deletes the variable specified by VarName and VarGuid.\r
\r
  @param VarName           A Null-terminated Unicode string that is\r
                           the name of the vendor's variable.\r
\r
  @param VarGuid           A unique identifier for the vendor.\r
\r
  @retval  EFI_SUCCESS           The variable was found and removed\r
  @retval  EFI_UNSUPPORTED       The variable store was inaccessible\r
  @retval  EFI_OUT_OF_RESOURCES  The temporary buffer was not available\r
  @retval  EFI_NOT_FOUND         The variable was not found\r
\r
**/\r
EFI_STATUS\r
EfiLibDeleteVariable (\r
  IN CHAR16   *VarName,\r
  IN EFI_GUID *VarGuid\r
  )\r
{\r
  VOID        *VarBuf;\r
  EFI_STATUS  Status;\r
\r
  VarBuf  = EfiLibGetVariable (VarName, VarGuid);\r
  Status  = EFI_NOT_FOUND;\r
\r
  if (VarBuf != NULL) {\r
    //\r
    // Delete variable from Storage\r
    //\r
    Status = gRT->SetVariable (\r
                    VarName,\r
                    VarGuid,\r
                    EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,\r
                    0,\r
                    NULL\r
                    );\r
    //\r
    // Deleting variable with current variable implementation shouldn't fail.\r
    //\r
    ASSERT_EFI_ERROR (Status);\r
    FreePool (VarBuf);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
\r
  Function gets the file system information from an open file descriptor,\r
  and stores it in a buffer allocated from pool.\r
\r
\r
  @param FHand           The file handle.\r
\r
  @return                A pointer to a buffer with file information.\r
  @retval                NULL is returned if failed to get Vaolume Label Info.\r
\r
**/\r
EFI_FILE_SYSTEM_VOLUME_LABEL *\r
EfiLibFileSystemVolumeLabelInfo (\r
  IN EFI_FILE_HANDLE      FHand\r
  )\r
{\r
  EFI_STATUS                        Status;\r
  EFI_FILE_SYSTEM_VOLUME_LABEL      *Buffer;\r
  UINTN                             BufferSize;\r
  //\r
  // Initialize for GrowBuffer loop\r
  //\r
  Buffer      = NULL;\r
  BufferSize  = SIZE_OF_EFI_FILE_SYSTEM_VOLUME_LABEL + 200;\r
\r
  //\r
  // Call the real function\r
  //\r
  while (EfiGrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {\r
    Status = FHand->GetInfo (\r
                      FHand,\r
                      &gEfiFileSystemVolumeLabelInfoIdGuid,\r
                      &BufferSize,\r
                      Buffer\r
                      );\r
  }\r
\r
  return Buffer;\r
}\r
\r
/**\r
  Duplicate a string.\r
\r
  @param Src             The source.\r
\r
  @return A new string which is duplicated copy of the source.\r
  @retval NULL If there is not enough memory.\r
\r
**/\r
CHAR16 *\r
EfiStrDuplicate (\r
  IN CHAR16   *Src\r
  )\r
{\r
  CHAR16  *Dest;\r
  UINTN   Size;\r
\r
  Size  = StrSize (Src);\r
  Dest  = AllocateZeroPool (Size);\r
  ASSERT (Dest != NULL);\r
  if (Dest != NULL) {\r
    CopyMem (Dest, Src, Size);\r
  }\r
\r
  return Dest;\r
}\r
\r
/**\r
\r
  Function gets the file information from an open file descriptor, and stores it\r
  in a buffer allocated from pool.\r
\r
  @param FHand           File Handle.\r
\r
  @return                A pointer to a buffer with file information or NULL is returned\r
\r
**/\r
EFI_FILE_INFO *\r
EfiLibFileInfo (\r
  IN EFI_FILE_HANDLE      FHand\r
  )\r
{\r
  EFI_STATUS    Status;\r
  EFI_FILE_INFO *Buffer;\r
  UINTN         BufferSize;\r
\r
  //\r
  // Initialize for GrowBuffer loop\r
  //\r
  Buffer      = NULL;\r
  BufferSize  = SIZE_OF_EFI_FILE_INFO + 200;\r
\r
  //\r
  // Call the real function\r
  //\r
  while (EfiGrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {\r
    Status = FHand->GetInfo (\r
                      FHand,\r
                      &gEfiFileInfoGuid,\r
                      &BufferSize,\r
                      Buffer\r
                      );\r
  }\r
\r
  return Buffer;\r
}\r
\r
/**\r
  Function is used to determine the number of device path instances\r
  that exist in a device path.\r
\r
\r
  @param DevicePath      A pointer to a device path data structure.\r
\r
  @return This function counts and returns the number of device path instances\r
          in DevicePath.\r
\r
**/\r
UINTN\r
EfiDevicePathInstanceCount (\r
  IN EFI_DEVICE_PATH_PROTOCOL      *DevicePath\r
  )\r
{\r
  UINTN Count;\r
  UINTN Size;\r
\r
  Count = 0;\r
  while (GetNextDevicePathInstance (&DevicePath, &Size) != NULL) {\r
    Count += 1;\r
  }\r
\r
  return Count;\r
}\r
\r
/**\r
  Adjusts the size of a previously allocated buffer.\r
\r
\r
  @param OldPool         - A pointer to the buffer whose size is being adjusted.\r
  @param OldSize         - The size of the current buffer.\r
  @param NewSize         - The size of the new buffer.\r
\r
  @return   The newly allocated buffer.\r
  @retval   NULL  Allocation failed.\r
\r
**/\r
VOID *\r
EfiReallocatePool (\r
  IN VOID                 *OldPool,\r
  IN UINTN                OldSize,\r
  IN UINTN                NewSize\r
  )\r
{\r
  VOID  *NewPool;\r
\r
  NewPool = NULL;\r
  if (NewSize != 0) {\r
    NewPool = AllocateZeroPool (NewSize);\r
  }\r
\r
  if (OldPool != NULL) {\r
    if (NewPool != NULL) {\r
      CopyMem (NewPool, OldPool, OldSize < NewSize ? OldSize : NewSize);\r
    }\r
\r
    FreePool (OldPool);\r
  }\r
\r
  return NewPool;\r
}\r
\r
/**\r
  Get a string from the Data Hub record based on\r
  a device path.\r
\r
  @param DevPath         The device Path.\r
\r
  @return A string located from the Data Hub records based on\r
          the device path.\r
  @retval NULL  If failed to get the String from Data Hub.\r
\r
**/\r
UINT16 *\r
EfiLibStrFromDatahub (\r
  IN EFI_DEVICE_PATH_PROTOCOL                 *DevPath\r
  )\r
{\r
  return NULL;\r
}\r
\r
/**\r
\r
  Find the first instance of this Protocol\r
  in the system and return it's interface.\r
\r
\r
  @param ProtocolGuid    Provides the protocol to search for\r
  @param Interface       On return, a pointer to the first interface\r
                         that matches ProtocolGuid\r
\r
  @retval  EFI_SUCCESS      A protocol instance matching ProtocolGuid was found\r
  @retval  EFI_NOT_FOUND    No protocol instances were found that match ProtocolGuid\r
\r
**/\r
EFI_STATUS\r
EfiLibLocateProtocol (\r
  IN  EFI_GUID    *ProtocolGuid,\r
  OUT VOID        **Interface\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  Status = gBS->LocateProtocol (\r
                  ProtocolGuid,\r
                  NULL,\r
                  (VOID **) Interface\r
                  );\r
  return Status;\r
}\r
\r
Commit	Line	Data
5c08e117	1	/** @file\r
	2	Utility routines used by boot maintenance modules.\r
	3	\r
0a6f4824	4	Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.<BR>\r
180a5a35	5	This program and the accompanying materials\r
5c08e117	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	**/\r
	14	\r
	15	#include "BootMaint.h"\r
	16	\r
5c08e117	17	/**\r
	18	\r
	19	Function opens and returns a file handle to the root directory of a volume.\r
	20	\r
	21	@param DeviceHandle A handle for a device\r
	22	\r
	23	@return A valid file handle or NULL is returned\r
	24	\r
	25	**/\r
	26	EFI_FILE_HANDLE\r
	27	EfiLibOpenRoot (\r
	28	IN EFI_HANDLE DeviceHandle\r
	29	)\r
	30	{\r
	31	EFI_STATUS Status;\r
	32	EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Volume;\r
	33	EFI_FILE_HANDLE File;\r
	34	\r
	35	File = NULL;\r
	36	\r
	37	//\r
	38	// File the file system interface to the device\r
	39	//\r
	40	Status = gBS->HandleProtocol (\r
	41	DeviceHandle,\r
	42	&gEfiSimpleFileSystemProtocolGuid,\r
	43	(VOID *) &Volume\r
	44	);\r
	45	\r
	46	//\r
	47	// Open the root directory of the volume\r
	48	//\r
	49	if (!EFI_ERROR (Status)) {\r
	50	Status = Volume->OpenVolume (\r
	51	Volume,\r
	52	&File\r
	53	);\r
	54	}\r
	55	//\r
	56	// Done\r
	57	//\r
	58	return EFI_ERROR (Status) ? NULL : File;\r
	59	}\r
	60	\r
	61	/**\r
	62	\r
	63	Helper function called as part of the code needed\r
	64	to allocate the proper sized buffer for various\r
	65	EFI interfaces.\r
	66	\r
	67	\r
	68	@param Status Current status\r
	69	@param Buffer Current allocated buffer, or NULL\r
	70	@param BufferSize Current buffer size needed\r
	71	\r
	72	@retval TRUE if the buffer was reallocated and the caller\r
	73	should try the API again.\r
	74	@retval FALSE The caller should not call this function again.\r
	75	\r
	76	**/\r
	77	BOOLEAN\r
	78	EfiGrowBuffer (\r
	79	IN OUT EFI_STATUS *Status,\r
	80	IN OUT VOID **Buffer,\r
81	IN UINTN BufferSize\r
82	)\r
83	{\r
84	BOOLEAN TryAgain;\r
85	\r
86	//\r
87	// If this is an initial request, buffer will be null with a new buffer size\r
88	//\r
89	if ((*Buffer == NULL) && (BufferSize != 0)) {\r
90	*Status = EFI_BUFFER_TOO_SMALL;\r
91	}\r
92	//\r
93	// If the status code is "buffer too small", resize the buffer\r
94	//\r
95	TryAgain = FALSE;\r
96	if (*Status == EFI_BUFFER_TOO_SMALL) {\r
97	\r
98	if (*Buffer != NULL) {\r
99	FreePool (*Buffer);\r
100	}\r
101	\r
102	*Buffer = AllocateZeroPool (BufferSize);\r
103	\r
104	if (*Buffer != NULL) {\r
105	TryAgain = TRUE;\r
106	} else {\r
107	*Status = EFI_OUT_OF_RESOURCES;\r
108	}\r
109	}\r
110	//\r
111	// If there's an error, free the buffer\r
112	//\r
113	if (!TryAgain && EFI_ERROR (Status) && (Buffer != NULL)) {\r
114	FreePool (*Buffer);\r
115	*Buffer = NULL;\r
116	}\r
117	\r
118	return TryAgain;\r
119	}\r
120	\r
121	/**\r
122	Function returns the value of the specified variable.\r
123	\r
124	\r
125	@param Name A Null-terminated Unicode string that is\r
126	the name of the vendor's variable.\r
127	@param VendorGuid A unique identifier for the vendor.\r
128	\r
129	@return The payload of the variable.\r
130	@retval NULL If the variable can't be read.\r
131	\r
132	**/\r
133	VOID *\r
134	EfiLibGetVariable (\r
135	IN CHAR16 *Name,\r
136	IN EFI_GUID *VendorGuid\r
137	)\r
138	{\r
139	UINTN VarSize;\r
140	\r
141	return BdsLibGetVariableAndSize (Name, VendorGuid, &VarSize);\r
142	}\r
143	\r
144	/**\r
145	Function deletes the variable specified by VarName and VarGuid.\r
146	\r
147	@param VarName A Null-terminated Unicode string that is\r
148	the name of the vendor's variable.\r
0a6f4824	149	\r
5c08e117	150	@param VarGuid A unique identifier for the vendor.\r
	151	\r
	152	@retval EFI_SUCCESS The variable was found and removed\r
	153	@retval EFI_UNSUPPORTED The variable store was inaccessible\r
	154	@retval EFI_OUT_OF_RESOURCES The temporary buffer was not available\r
	155	@retval EFI_NOT_FOUND The variable was not found\r
	156	\r
	157	**/\r
	158	EFI_STATUS\r
	159	EfiLibDeleteVariable (\r
	160	IN CHAR16 *VarName,\r
	161	IN EFI_GUID *VarGuid\r
	162	)\r
	163	{\r
	164	VOID *VarBuf;\r
	165	EFI_STATUS Status;\r
	166	\r
	167	VarBuf = EfiLibGetVariable (VarName, VarGuid);\r
	168	Status = EFI_NOT_FOUND;\r
	169	\r
	170	if (VarBuf != NULL) {\r
	171	//\r
	172	// Delete variable from Storage\r
	173	//\r
16e5944a RN	174	Status = gRT->SetVariable (\r
	175	VarName,\r
	176	VarGuid,\r
	177	EFI_VARIABLE_BOOTSERVICE_ACCESS \| EFI_VARIABLE_RUNTIME_ACCESS \| EFI_VARIABLE_NON_VOLATILE,\r
	178	0,\r
	179	NULL\r
	180	);\r
69fc8f08 RN	181	//\r
	182	// Deleting variable with current variable implementation shouldn't fail.\r
	183	//\r
	184	ASSERT_EFI_ERROR (Status);\r
5c08e117	185	FreePool (VarBuf);\r
	186	}\r
	187	\r
	188	return Status;\r
	189	}\r
	190	\r
	191	/**\r
	192	\r
	193	Function gets the file system information from an open file descriptor,\r
	194	and stores it in a buffer allocated from pool.\r
	195	\r
	196	\r
	197	@param FHand The file handle.\r
	198	\r
	199	@return A pointer to a buffer with file information.\r
	200	@retval NULL is returned if failed to get Vaolume Label Info.\r
	201	\r
	202	**/\r
	203	EFI_FILE_SYSTEM_VOLUME_LABEL *\r
	204	EfiLibFileSystemVolumeLabelInfo (\r
	205	IN EFI_FILE_HANDLE FHand\r
	206	)\r
	207	{\r
	208	EFI_STATUS Status;\r
	209	EFI_FILE_SYSTEM_VOLUME_LABEL *Buffer;\r
	210	UINTN BufferSize;\r
	211	//\r
	212	// Initialize for GrowBuffer loop\r
	213	//\r
	214	Buffer = NULL;\r
	215	BufferSize = SIZE_OF_EFI_FILE_SYSTEM_VOLUME_LABEL + 200;\r
	216	\r
	217	//\r
	218	// Call the real function\r
	219	//\r
	220	while (EfiGrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {\r
	221	Status = FHand->GetInfo (\r
	222	FHand,\r
	223	&gEfiFileSystemVolumeLabelInfoIdGuid,\r
	224	&BufferSize,\r
	225	Buffer\r
	226	);\r
	227	}\r
	228	\r
	229	return Buffer;\r
	230	}\r
	231	\r
	232	/**\r
	233	Duplicate a string.\r
	234	\r
	235	@param Src The source.\r
	236	\r
	237	@return A new string which is duplicated copy of the source.\r
	238	@retval NULL If there is not enough memory.\r
	239	\r
	240	**/\r
	241	CHAR16 *\r
	242	EfiStrDuplicate (\r
	243	IN CHAR16 *Src\r
	244	)\r
	245	{\r
	246	CHAR16 *Dest;\r
	247	UINTN Size;\r
	248	\r
249	Size = StrSize (Src);\r
250	Dest = AllocateZeroPool (Size);\r
251	ASSERT (Dest != NULL);\r
252	if (Dest != NULL) {\r
253	CopyMem (Dest, Src, Size);\r
254	}\r
255	\r
256	return Dest;\r
257	}\r
258	\r
259	/**\r
260	\r
261	Function gets the file information from an open file descriptor, and stores it\r
262	in a buffer allocated from pool.\r
263	\r
264	@param FHand File Handle.\r
265	\r
266	@return A pointer to a buffer with file information or NULL is returned\r
267	\r
268	**/\r
269	EFI_FILE_INFO *\r
270	EfiLibFileInfo (\r
271	IN EFI_FILE_HANDLE FHand\r
272	)\r
273	{\r
274	EFI_STATUS Status;\r
275	EFI_FILE_INFO *Buffer;\r
276	UINTN BufferSize;\r
277	\r
278	//\r
279	// Initialize for GrowBuffer loop\r
280	//\r
281	Buffer = NULL;\r
282	BufferSize = SIZE_OF_EFI_FILE_INFO + 200;\r
283	\r
284	//\r
285	// Call the real function\r
286	//\r
287	while (EfiGrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {\r
288	Status = FHand->GetInfo (\r
289	FHand,\r
290	&gEfiFileInfoGuid,\r
291	&BufferSize,\r
292	Buffer\r
293	);\r
294	}\r
295	\r
296	return Buffer;\r
297	}\r
298	\r
299	/**\r
300	Function is used to determine the number of device path instances\r
301	that exist in a device path.\r
302	\r
303	\r
304	@param DevicePath A pointer to a device path data structure.\r
305	\r
306	@return This function counts and returns the number of device path instances\r
307	in DevicePath.\r
308	\r
309	**/\r
310	UINTN\r
311	EfiDevicePathInstanceCount (\r
312	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
313	)\r
314	{\r
315	UINTN Count;\r
316	UINTN Size;\r
317	\r
318	Count = 0;\r
7ec9caab	319	while (GetNextDevicePathInstance (&DevicePath, &Size) != NULL) {\r
5c08e117	320	Count += 1;\r
	321	}\r
	322	\r
	323	return Count;\r
	324	}\r
	325	\r
	326	/**\r
	327	Adjusts the size of a previously allocated buffer.\r
	328	\r
	329	\r
	330	@param OldPool - A pointer to the buffer whose size is being adjusted.\r
	331	@param OldSize - The size of the current buffer.\r
	332	@param NewSize - The size of the new buffer.\r
	333	\r
	334	@return The newly allocated buffer.\r
	335	@retval NULL Allocation failed.\r
	336	\r
	337	**/\r
	338	VOID *\r
	339	EfiReallocatePool (\r
	340	IN VOID *OldPool,\r
	341	IN UINTN OldSize,\r
	342	IN UINTN NewSize\r
	343	)\r
	344	{\r
	345	VOID *NewPool;\r
	346	\r
	347	NewPool = NULL;\r
	348	if (NewSize != 0) {\r
	349	NewPool = AllocateZeroPool (NewSize);\r
	350	}\r
	351	\r
	352	if (OldPool != NULL) {\r
	353	if (NewPool != NULL) {\r
	354	CopyMem (NewPool, OldPool, OldSize < NewSize ? OldSize : NewSize);\r
	355	}\r
	356	\r
	357	FreePool (OldPool);\r
	358	}\r
	359	\r
	360	return NewPool;\r
	361	}\r
	362	\r
5c08e117	363	/**\r
0a6f4824	364	Get a string from the Data Hub record based on\r
5c08e117	365	a device path.\r
	366	\r
	367	@param DevPath The device Path.\r
	368	\r
	369	@return A string located from the Data Hub records based on\r
	370	the device path.\r
	371	@retval NULL If failed to get the String from Data Hub.\r
	372	\r
	373	**/\r
	374	UINT16 *\r
	375	EfiLibStrFromDatahub (\r
	376	IN EFI_DEVICE_PATH_PROTOCOL *DevPath\r
	377	)\r
	378	{\r
5c08e117	379	return NULL;\r
5c08e117	380	}\r
be9304f3 ED	381	\r
	382	/**\r
	383	\r
	384	Find the first instance of this Protocol\r
	385	in the system and return it's interface.\r
	386	\r
	387	\r
	388	@param ProtocolGuid Provides the protocol to search for\r
	389	@param Interface On return, a pointer to the first interface\r
	390	that matches ProtocolGuid\r
	391	\r
	392	@retval EFI_SUCCESS A protocol instance matching ProtocolGuid was found\r
	393	@retval EFI_NOT_FOUND No protocol instances were found that match ProtocolGuid\r
	394	\r
	395	**/\r
	396	EFI_STATUS\r
	397	EfiLibLocateProtocol (\r
	398	IN EFI_GUID *ProtocolGuid,\r
	399	OUT VOID **Interface\r
	400	)\r
	401	{\r
	402	EFI_STATUS Status;\r
	403	\r
	404	Status = gBS->LocateProtocol (\r
	405	ProtocolGuid,\r
	406	NULL,\r
	407	(VOID **) Interface\r
	408	);\r
	409	return Status;\r
	410	}\r
	411	\r