/** @file Library instance that implement UEFI Device Path Library class based on protocol gEfiDevicePathUtilitiesProtocolGuid. Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at http://opensource.org/licenses/bsd-license.php. THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ #include <Uefi.h> #include <Protocol/DevicePathUtilities.h> #include <Protocol/DevicePathToText.h> #include <Protocol/DevicePathFromText.h> #include <Library/DevicePathLib.h> #include <Library/DebugLib.h> #include <Library/BaseLib.h> #include <Library/MemoryAllocationLib.h> #include <Library/BaseMemoryLib.h> #include <Library/UefiBootServicesTableLib.h> #include <Library/PcdLib.h> GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_UTILITIES_PROTOCOL *mDevicePathLibDevicePathUtilities = NULL; GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *mDevicePathLibDevicePathToText = NULL; GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *mDevicePathLibDevicePathFromText = NULL; // // Template for an end-of-device path node. // GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = { END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE, { END_DEVICE_PATH_LENGTH, 0 } }; /** The constructor function caches the pointer to DevicePathUtilites protocol. The constructor function locates DevicePathUtilities protocol from protocol database. It will ASSERT() if that operation fails and it will always return EFI_SUCCESS. @param ImageHandle The firmware allocated handle for the EFI image. @param SystemTable A pointer to the EFI System Table. @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS. **/ EFI_STATUS EFIAPI DevicePathLibConstructor ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { EFI_STATUS Status; Status = gBS->LocateProtocol ( &gEfiDevicePathUtilitiesProtocolGuid, NULL, (VOID**) &mDevicePathLibDevicePathUtilities ); ASSERT_EFI_ERROR (Status); ASSERT (mDevicePathLibDevicePathUtilities != NULL); return Status; } /** Determine whether a given device path is valid. If DevicePath is NULL, then ASSERT(). @param DevicePath A pointer to a device path data structure. @param MaxSize The maximum size of the device path data structure. @retval TRUE DevicePath is valid. @retval FALSE The length of any node node in the DevicePath is less than sizeof (EFI_DEVICE_PATH_PROTOCOL). @retval FALSE If MaxSize is not zero, the size of the DevicePath exceeds MaxSize. @retval FALSE If PcdMaximumDevicePathNodeCount is not zero, the node count of the DevicePath exceeds PcdMaximumDevicePathNodeCount. **/ BOOLEAN EFIAPI IsDevicePathValid ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, IN UINTN MaxSize ) { UINTN Count; UINTN Size; UINTN NodeLength; ASSERT (DevicePath != NULL); if (MaxSize == 0) { MaxSize = MAX_UINTN; } // // Validate the input size big enough to touch the first node. // if (MaxSize < sizeof (EFI_DEVICE_PATH_PROTOCOL)) { return FALSE; } for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) { NodeLength = DevicePathNodeLength (DevicePath); if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) { return FALSE; } if (NodeLength > MAX_UINTN - Size) { return FALSE; } Size += NodeLength; // // Validate next node before touch it. // if (Size > MaxSize - END_DEVICE_PATH_LENGTH ) { return FALSE; } if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) { Count++; if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) { return FALSE; } } } // // Only return TRUE when the End Device Path node is valid. // return (BOOLEAN) (DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH); } /** Returns the Type field of a device path node. Returns the Type field of the device path node specified by Node. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @return The Type field of the device path node specified by Node. **/ UINT8 EFIAPI DevicePathType ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type; } /** Returns the SubType field of a device path node. Returns the SubType field of the device path node specified by Node. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @return The SubType field of the device path node specified by Node. **/ UINT8 EFIAPI DevicePathSubType ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType; } /** Returns the 16-bit Length field of a device path node. Returns the 16-bit Length field of the device path node specified by Node. Node is not required to be aligned on a 16-bit boundary, so it is recommended that a function such as ReadUnaligned16() be used to extract the contents of the Length field. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @return The 16-bit Length field of the device path node specified by Node. **/ UINTN EFIAPI DevicePathNodeLength ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]); } /** Returns a pointer to the next node in a device path. Returns a pointer to the device path node that follows the device path node specified by Node. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @return a pointer to the device path node that follows the device path node specified by Node. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI NextDevicePathNode ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node)); } /** Determines if a device path node is an end node of a device path. This includes nodes that are the end of a device path instance and nodes that are the end of an entire device path. Determines if the device path node specified by Node is an end node of a device path. This includes nodes that are the end of a device path instance and nodes that are the end of an entire device path. If Node represents an end node of a device path, then TRUE is returned. Otherwise, FALSE is returned. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @retval TRUE The device path node specified by Node is an end node of a device path. @retval FALSE The device path node specified by Node is not an end node of a device path. **/ BOOLEAN EFIAPI IsDevicePathEndType ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE); } /** Determines if a device path node is an end node of an entire device path. Determines if a device path node specified by Node is an end node of an entire device path. If Node represents the end of an entire device path, then TRUE is returned. Otherwise, FALSE is returned. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @retval TRUE The device path node specified by Node is the end of an entire device path. @retval FALSE The device path node specified by Node is not the end of an entire device path. **/ BOOLEAN EFIAPI IsDevicePathEnd ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE); } /** Determines if a device path node is an end node of a device path instance. Determines if a device path node specified by Node is an end node of a device path instance. If Node represents the end of a device path instance, then TRUE is returned. Otherwise, FALSE is returned. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. @retval TRUE The device path node specified by Node is the end of a device path instance. @retval FALSE The device path node specified by Node is not the end of a device path instance. **/ BOOLEAN EFIAPI IsDevicePathEndInstance ( IN CONST VOID *Node ) { ASSERT (Node != NULL); return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE); } /** Sets the length, in bytes, of a device path node. Sets the length of the device path node specified by Node to the value specified by NodeLength. NodeLength is returned. Node is not required to be aligned on a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16() be used to set the contents of the Length field. If Node is NULL, then ASSERT(). If NodeLength >= SIZE_64KB, then ASSERT(). If NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL), then ASSERT(). @param Node A pointer to a device path node data structure. @param Length The length, in bytes, of the device path node. @return Length **/ UINT16 EFIAPI SetDevicePathNodeLength ( IN OUT VOID *Node, IN UINTN Length ) { ASSERT (Node != NULL); ASSERT ((Length >= sizeof (EFI_DEVICE_PATH_PROTOCOL)) && (Length < SIZE_64KB)); return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length)); } /** Fills in all the fields of a device path node that is the end of an entire device path. Fills in all the fields of a device path node specified by Node so Node represents the end of an entire device path. The Type field of Node is set to END_DEVICE_PATH_TYPE, the SubType field of Node is set to END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16() be used to set the contents of the Length field. If Node is NULL, then ASSERT(). @param Node A pointer to a device path node data structure. **/ VOID EFIAPI SetDevicePathEndNode ( OUT VOID *Node ) { ASSERT (Node != NULL); CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath)); } /** Returns the size of a device path in bytes. This function returns the size, in bytes, of the device path data structure specified by DevicePath including the end of device path node. If DevicePath is NULL or invalid, then 0 is returned. @param DevicePath A pointer to a device path data structure. @retval 0 If DevicePath is NULL or invalid. @retval Others The size of a device path in bytes. **/ UINTN EFIAPI GetDevicePathSize ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath ) { return mDevicePathLibDevicePathUtilities->GetDevicePathSize (DevicePath); } /** Creates a new copy of an existing device path. This function allocates space for a new copy of the device path specified by DevicePath. If DevicePath is NULL, then NULL is returned. If the memory is successfully allocated, then the contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned. The memory for the new device path is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. @param DevicePath A pointer to a device path data structure. @retval NULL If DevicePath is NULL or invalid. @retval Others A pointer to the duplicated device path. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI DuplicateDevicePath ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath ) { return mDevicePathLibDevicePathUtilities->DuplicateDevicePath (DevicePath); } /** Creates a new device path by appending a second device path to a first device path. This function creates a new device path by appending a copy of SecondDevicePath to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from SecondDevicePath is retained. The newly created device path is returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is returned. If there is not enough memory for the newly allocated buffer, then NULL is returned. The memory for the new device path is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. @param FirstDevicePath A pointer to a device path data structure. @param SecondDevicePath A pointer to a device path data structure. @retval NULL If there is not enough memory for the newly allocated buffer. @retval NULL If FirstDevicePath or SecondDevicePath is invalid. @retval Others A pointer to the new device path if success. Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI AppendDevicePath ( IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL ) { return mDevicePathLibDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath); } /** Creates a new path by appending the device node to the device path. This function creates a new device path by appending a copy of the device node specified by DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer. The end-of-device-path device node is moved after the end of the appended device node. If DevicePathNode is NULL then a copy of DevicePath is returned. If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device path device node is returned. If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path device node is returned. If there is not enough memory to allocate space for the new device path, then NULL is returned. The memory is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. @param DevicePath A pointer to a device path data structure. @param DevicePathNode A pointer to a single device path node. @retval NULL If there is not enough memory for the new device path. @retval Others A pointer to the new device path if success. A copy of DevicePathNode followed by an end-of-device-path node if both FirstDevicePath and SecondDevicePath are NULL. A copy of an end-of-device-path node if both FirstDevicePath and SecondDevicePath are NULL. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI AppendDevicePathNode ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL ) { return mDevicePathLibDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode); } /** Creates a new device path by appending the specified device path instance to the specified device path. This function creates a new device path by appending a copy of the device path instance specified by DevicePathInstance to a copy of the device path specified by DevicePath in a allocated buffer. The end-of-device-path device node is moved after the end of the appended device path instance and a new end-of-device-path-instance node is inserted between. If DevicePath is NULL, then a copy if DevicePathInstance is returned. If DevicePathInstance is NULL, then NULL is returned. If DevicePath or DevicePathInstance is invalid, then NULL is returned. If there is not enough memory to allocate space for the new device path, then NULL is returned. The memory is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. @param DevicePath A pointer to a device path data structure. @param DevicePathInstance A pointer to a device path instance. @return A pointer to the new device path. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI AppendDevicePathInstance ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL ) { return mDevicePathLibDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance); } /** Creates a copy of the current device path instance and returns a pointer to the next device path instance. This function creates a copy of the current device path instance. It also updates DevicePath to point to the next device path instance in the device path (or NULL if no more) and updates Size to hold the size of the device path instance copy. If DevicePath is NULL, then NULL is returned. If there is not enough memory to allocate space for the new device path, then NULL is returned. The memory is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. If Size is NULL, then ASSERT(). @param DevicePath On input, this holds the pointer to the current device path instance. On output, this holds the pointer to the next device path instance or NULL if there are no more device path instances in the device path pointer to a device path data structure. @param Size On output, this holds the size of the device path instance, in bytes or zero, if DevicePath is NULL. @return A pointer to the current device path instance. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI GetNextDevicePathInstance ( IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath, OUT UINTN *Size ) { ASSERT (Size != NULL); return mDevicePathLibDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size); } /** Creates a device node. This function creates a new device node in a newly allocated buffer of size NodeLength and initializes the device path node header with NodeType and NodeSubType. The new device path node is returned. If NodeLength is smaller than a device path header, then NULL is returned. If there is not enough memory to allocate space for the new device path, then NULL is returned. The memory is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. @param NodeType The device node type for the new device node. @param NodeSubType The device node sub-type for the new device node. @param NodeLength The length of the new device node. @return The new device path. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI CreateDeviceNode ( IN UINT8 NodeType, IN UINT8 NodeSubType, IN UINT16 NodeLength ) { return mDevicePathLibDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength); } /** Determines if a device path is single or multi-instance. This function returns TRUE if the device path specified by DevicePath is multi-instance. Otherwise, FALSE is returned. If DevicePath is NULL or invalid, then FALSE is returned. @param DevicePath A pointer to a device path data structure. @retval TRUE DevicePath is multi-instance. @retval FALSE DevicePath is not multi-instance, or DevicePath is NULL or invalid. **/ BOOLEAN EFIAPI IsDevicePathMultiInstance ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath ) { return mDevicePathLibDevicePathUtilities->IsDevicePathMultiInstance (DevicePath); } /** Retrieves the device path protocol from a handle. This function returns the device path protocol from the handle specified by Handle. If Handle is NULL or Handle does not contain a device path protocol, then NULL is returned. @param Handle The handle from which to retrieve the device path protocol. @return The device path protocol from the handle specified by Handle. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI DevicePathFromHandle ( IN EFI_HANDLE Handle ) { EFI_DEVICE_PATH_PROTOCOL *DevicePath; EFI_STATUS Status; Status = gBS->HandleProtocol ( Handle, &gEfiDevicePathProtocolGuid, (VOID *) &DevicePath ); if (EFI_ERROR (Status)) { DevicePath = NULL; } return DevicePath; } /** Allocates a device path for a file and appends it to an existing device path. If Device is a valid device handle that contains a device path protocol, then a device path for the file specified by FileName is allocated and appended to the device path associated with the handle Device. The allocated device path is returned. If Device is NULL or Device is a handle that does not support the device path protocol, then a device path containing a single device path node for the file specified by FileName is allocated and returned. The memory for the new device path is allocated from EFI boot services memory. It is the responsibility of the caller to free the memory allocated. If FileName is NULL, then ASSERT(). If FileName is not aligned on a 16-bit boundary, then ASSERT(). @param Device A pointer to a device handle. This parameter is optional and may be NULL. @param FileName A pointer to a Null-terminated Unicode string. @return The allocated device path. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI FileDevicePath ( IN EFI_HANDLE Device, OPTIONAL IN CONST CHAR16 *FileName ) { UINTN Size; FILEPATH_DEVICE_PATH *FilePath; EFI_DEVICE_PATH_PROTOCOL *DevicePath; EFI_DEVICE_PATH_PROTOCOL *FileDevicePath; DevicePath = NULL; Size = StrSize (FileName); FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH); if (FileDevicePath != NULL) { FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath; FilePath->Header.Type = MEDIA_DEVICE_PATH; FilePath->Header.SubType = MEDIA_FILEPATH_DP; CopyMem (&FilePath->PathName, FileName, Size); SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH); SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header)); if (Device != NULL) { DevicePath = DevicePathFromHandle (Device); } DevicePath = AppendDevicePath (DevicePath, FileDevicePath); FreePool (FileDevicePath); } return DevicePath; } /** Locate and return the protocol instance identified by the ProtocolGuid. @param ProtocolGuid The GUID of the protocol. @return A pointer to the protocol instance or NULL when absent. **/ VOID * UefiDevicePathLibLocateProtocol ( EFI_GUID *ProtocolGuid ) { EFI_STATUS Status; VOID *Protocol; Status = gBS->LocateProtocol ( ProtocolGuid, NULL, (VOID**) &Protocol ); if (EFI_ERROR (Status)) { return NULL; } else { return Protocol; } } /** Converts a device node to its string representation. @param DeviceNode A Pointer to the device node to be converted. @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation of the display node is used, where applicable. If DisplayOnly is FALSE, then the longer text representation of the display node is used. @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text representation for a device node can be used, where applicable. @return A pointer to the allocated text representation of the device node or NULL if DeviceNode is NULL or there was insufficient memory. **/ CHAR16 * EFIAPI ConvertDeviceNodeToText ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode, IN BOOLEAN DisplayOnly, IN BOOLEAN AllowShortcuts ) { if (mDevicePathLibDevicePathToText == NULL) { mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid); } if (mDevicePathLibDevicePathToText != NULL) { return mDevicePathLibDevicePathToText->ConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts); } else { return NULL; } } /** Converts a device path to its text representation. @param DevicePath A Pointer to the device to be converted. @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation of the display node is used, where applicable. If DisplayOnly is FALSE, then the longer text representation of the display node is used. @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text representation for a device node can be used, where applicable. @return A pointer to the allocated text representation of the device path or NULL if DeviceNode is NULL or there was insufficient memory. **/ CHAR16 * EFIAPI ConvertDevicePathToText ( IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, IN BOOLEAN DisplayOnly, IN BOOLEAN AllowShortcuts ) { if (mDevicePathLibDevicePathToText == NULL) { mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid); } if (mDevicePathLibDevicePathToText != NULL) { return mDevicePathLibDevicePathToText->ConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts); } else { return NULL; } } /** Convert text to the binary representation of a device node. @param TextDeviceNode TextDeviceNode points to the text representation of a device node. Conversion starts with the first character and continues until the first non-device node character. @return A pointer to the EFI device node or NULL if TextDeviceNode is NULL or there was insufficient memory or text unsupported. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI ConvertTextToDeviceNode ( IN CONST CHAR16 *TextDeviceNode ) { if (mDevicePathLibDevicePathFromText == NULL) { mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid); } if (mDevicePathLibDevicePathFromText != NULL) { return mDevicePathLibDevicePathFromText->ConvertTextToDeviceNode (TextDeviceNode); } else { return NULL; } } /** Convert text to the binary representation of a device path. @param TextDevicePath TextDevicePath points to the text representation of a device path. Conversion starts with the first character and continues until the first non-device node character. @return A pointer to the allocated device path or NULL if TextDeviceNode is NULL or there was insufficient memory. **/ EFI_DEVICE_PATH_PROTOCOL * EFIAPI ConvertTextToDevicePath ( IN CONST CHAR16 *TextDevicePath ) { if (mDevicePathLibDevicePathFromText == NULL) { mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid); } if (mDevicePathLibDevicePathFromText != NULL) { return mDevicePathLibDevicePathFromText->ConvertTextToDevicePath (TextDevicePath); } else { return NULL; } }