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- /** @file
- Device Path services. The thing to remember is device paths are built out of
- nodes. The device path is terminated by an end node that is length
- sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)
- all over this file.
- The only place where multi-instance device paths are supported is in
- environment variables. Multi-instance device paths should never be placed
- on a Handle.
- Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
- SPDX-License-Identifier: BSD-2-Clause-Patent
- **/
- #include "UefiDevicePathLib.h"
- #include <Protocol/DevicePathUtilities.h>
- //
- // Template for an end-of-device path node.
- //
- CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {
- END_DEVICE_PATH_TYPE,
- END_ENTIRE_DEVICE_PATH_SUBTYPE,
- {
- END_DEVICE_PATH_LENGTH,
- 0
- }
- };
- /**
- Determine whether a given device path is valid.
- @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 DevicePath is NULL.
- @retval FALSE Maxsize is less than sizeof(EFI_DEVICE_PATH_PROTOCOL).
- @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
- IsDevicePathValid (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
- UINTN MaxSize
- )
- {
- UINTN Count;
- UINTN Size;
- UINTN NodeLength;
- //
- // Validate the input whether exists and its size big enough to touch the first node
- //
- if (DevicePath == NULL || (MaxSize > 0 && MaxSize < END_DEVICE_PATH_LENGTH)) {
- return FALSE;
- }
- if (MaxSize == 0) {
- MaxSize = MAX_UINT32;
- }
- 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_UINT32 - Size) {
- return FALSE;
- }
- Size += NodeLength;
- //
- // Validate next node before touch it.
- //
- if (Size > MaxSize - END_DEVICE_PATH_LENGTH ) {
- return FALSE;
- }
- Count++;
- if (Count >= MAX_DEVICE_PATH_NODE_COUNT) {
- 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
- DevicePathType (
- 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
- DevicePathSubType (
- 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
- DevicePathNodeLength (
- 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 *
- NextDevicePathNode (
- 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
- IsDevicePathEndType (
- 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
- IsDevicePathEnd (
- 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
- IsDevicePathEndInstance (
- 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
- SetDevicePathNodeLength (
- VOID *Node,
- 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
- SetDevicePathEndNode (
- VOID *Node
- )
- {
- ASSERT (Node != NULL);
- memcpy (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
- UefiDevicePathLibGetDevicePathSize (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
- )
- {
- CONST EFI_DEVICE_PATH_PROTOCOL *Start;
- if (DevicePath == NULL) {
- return 0;
- }
- if (!IsDevicePathValid (DevicePath, 0)) {
- return 0;
- }
- //
- // Search for the end of the device path structure
- //
- Start = DevicePath;
- while (!IsDevicePathEnd (DevicePath)) {
- DevicePath = NextDevicePathNode (DevicePath);
- }
- //
- // Compute the size and add back in the size of the end device path structure
- //
- return ((UINTN) DevicePath - (UINTN) Start) + DevicePathNodeLength (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 DevicePath is NULL or invalid.
- @retval Others A pointer to the duplicated device path.
- **/
- EFI_DEVICE_PATH_PROTOCOL *
- UefiDevicePathLibDuplicateDevicePath (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
- )
- {
- UINTN Size;
- //
- // Compute the size
- //
- Size = GetDevicePathSize (DevicePath);
- if (Size == 0) {
- return NULL;
- }
- //
- // Allocate space for duplicate device path
- //
- return AllocateCopyPool (Size, 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 *
- UefiDevicePathLibAppendDevicePath (
- CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath,
- CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath
- )
- {
- UINTN Size;
- UINTN Size1;
- UINTN Size2;
- EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
- EFI_DEVICE_PATH_PROTOCOL *DevicePath2;
- //
- // If there's only 1 path, just duplicate it.
- //
- if (FirstDevicePath == NULL) {
- return DuplicateDevicePath ((SecondDevicePath != NULL) ? SecondDevicePath : &mUefiDevicePathLibEndDevicePath);
- }
- if (SecondDevicePath == NULL) {
- return DuplicateDevicePath (FirstDevicePath);
- }
- if (!IsDevicePathValid (FirstDevicePath, 0) || !IsDevicePathValid (SecondDevicePath, 0)) {
- return NULL;
- }
- //
- // Allocate space for the combined device path. It only has one end node of
- // length EFI_DEVICE_PATH_PROTOCOL.
- //
- Size1 = GetDevicePathSize (FirstDevicePath);
- Size2 = GetDevicePathSize (SecondDevicePath);
- Size = Size1 + Size2 - END_DEVICE_PATH_LENGTH;
- NewDevicePath = AllocatePool (Size);
- if (NewDevicePath != NULL) {
- NewDevicePath = memcpy (NewDevicePath, FirstDevicePath, Size1);
- //
- // Over write FirstDevicePath EndNode and do the copy
- //
- DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath +
- (Size1 - END_DEVICE_PATH_LENGTH));
- memcpy (DevicePath2, SecondDevicePath, Size2);
- }
- return NewDevicePath;
- }
- /**
- 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 *
- UefiDevicePathLibAppendDevicePathNode (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode
- )
- {
- EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
- EFI_DEVICE_PATH_PROTOCOL *NextNode;
- EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
- UINTN NodeLength;
- if (DevicePathNode == NULL) {
- return DuplicateDevicePath ((DevicePath != NULL) ? DevicePath : &mUefiDevicePathLibEndDevicePath);
- }
- //
- // Build a Node that has a terminator on it
- //
- NodeLength = DevicePathNodeLength (DevicePathNode);
- TempDevicePath = AllocatePool (NodeLength + END_DEVICE_PATH_LENGTH);
- if (TempDevicePath == NULL) {
- return NULL;
- }
- TempDevicePath = memcpy (TempDevicePath, DevicePathNode, NodeLength);
- //
- // Add and end device path node to convert Node to device path
- //
- NextNode = NextDevicePathNode (TempDevicePath);
- SetDevicePathEndNode (NextNode);
- //
- // Append device paths
- //
- NewDevicePath = AppendDevicePath (DevicePath, TempDevicePath);
- free (TempDevicePath);
- return NewDevicePath;
- }
- /**
- 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 *
- UefiDevicePathLibAppendDevicePathInstance (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance
- )
- {
- EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
- EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
- UINTN SrcSize;
- UINTN InstanceSize;
- if (DevicePath == NULL) {
- return DuplicateDevicePath (DevicePathInstance);
- }
- if (DevicePathInstance == NULL) {
- return NULL;
- }
- if (!IsDevicePathValid (DevicePath, 0) || !IsDevicePathValid (DevicePathInstance, 0)) {
- return NULL;
- }
- SrcSize = GetDevicePathSize (DevicePath);
- InstanceSize = GetDevicePathSize (DevicePathInstance);
- NewDevicePath = AllocatePool (SrcSize + InstanceSize);
- if (NewDevicePath != NULL) {
- TempDevicePath = memcpy (NewDevicePath, DevicePath, SrcSize);;
- while (!IsDevicePathEnd (TempDevicePath)) {
- TempDevicePath = NextDevicePathNode (TempDevicePath);
- }
- TempDevicePath->SubType = END_INSTANCE_DEVICE_PATH_SUBTYPE;
- TempDevicePath = NextDevicePathNode (TempDevicePath);
- memcpy (TempDevicePath, DevicePathInstance, InstanceSize);
- }
- return NewDevicePath;
- }
- /**
- 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 DevicePath points to a invalid device path, 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 *
- UefiDevicePathLibGetNextDevicePathInstance (
- EFI_DEVICE_PATH_PROTOCOL **DevicePath,
- UINTN *Size
- )
- {
- EFI_DEVICE_PATH_PROTOCOL *DevPath;
- EFI_DEVICE_PATH_PROTOCOL *ReturnValue;
- UINT8 Temp;
- ASSERT (Size != NULL);
- if (DevicePath == NULL || *DevicePath == NULL) {
- *Size = 0;
- return NULL;
- }
- if (!IsDevicePathValid (*DevicePath, 0)) {
- return NULL;
- }
- //
- // Find the end of the device path instance
- //
- DevPath = *DevicePath;
- while (!IsDevicePathEndType (DevPath)) {
- DevPath = NextDevicePathNode (DevPath);
- }
- //
- // Compute the size of the device path instance
- //
- *Size = ((UINTN) DevPath - (UINTN) (*DevicePath)) + sizeof (EFI_DEVICE_PATH_PROTOCOL);
- //
- // Make a copy and return the device path instance
- //
- Temp = DevPath->SubType;
- DevPath->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
- ReturnValue = DuplicateDevicePath (*DevicePath);
- DevPath->SubType = Temp;
- //
- // If DevPath is the end of an entire device path, then another instance
- // does not follow, so *DevicePath is set to NULL.
- //
- if (DevicePathSubType (DevPath) == END_ENTIRE_DEVICE_PATH_SUBTYPE) {
- *DevicePath = NULL;
- } else {
- *DevicePath = NextDevicePathNode (DevPath);
- }
- return ReturnValue;
- }
- /**
- 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 *
- UefiDevicePathLibCreateDeviceNode (
- UINT8 NodeType,
- UINT8 NodeSubType,
- UINT16 NodeLength
- )
- {
- EFI_DEVICE_PATH_PROTOCOL *DevicePath;
- if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
- //
- // NodeLength is less than the size of the header.
- //
- return NULL;
- }
- DevicePath = AllocateZeroPool (NodeLength);
- if (DevicePath != NULL) {
- DevicePath->Type = NodeType;
- DevicePath->SubType = NodeSubType;
- SetDevicePathNodeLength (DevicePath, NodeLength);
- }
- return DevicePath;
- }
- /**
- 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
- UefiDevicePathLibIsDevicePathMultiInstance (
- CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
- )
- {
- CONST EFI_DEVICE_PATH_PROTOCOL *Node;
- if (DevicePath == NULL) {
- return FALSE;
- }
- if (!IsDevicePathValid (DevicePath, 0)) {
- return FALSE;
- }
- Node = DevicePath;
- while (!IsDevicePathEnd (Node)) {
- if (IsDevicePathEndInstance (Node)) {
- return TRUE;
- }
- Node = NextDevicePathNode (Node);
- }
- return FALSE;
- }
- /**
- 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 *
- DevicePathFromHandle (
- 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 *
- FileDevicePath (
- EFI_HANDLE Device, OPTIONAL
- 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;
- memcpy (&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);
- free (FileDevicePath);
- }
- return DevicePath;
- }
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