#include "UefiDevicePathLib.h"

Functions
EFI_STATUS EFIAPI	UefiDevicePathLibOptionalDevicePathProtocolConstructor (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

UINTN EFIAPI	GetDevicePathSize (IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	DuplicateDevicePath (IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	AppendDevicePath (IN CONST EFI_DEVICE_PATH_PROTOCOL FirstDevicePath OPTIONAL, IN CONST EFI_DEVICE_PATH_PROTOCOL SecondDevicePath OPTIONAL)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	AppendDevicePathNode (IN CONST EFI_DEVICE_PATH_PROTOCOL DevicePath OPTIONAL, IN CONST EFI_DEVICE_PATH_PROTOCOL DevicePathNode OPTIONAL)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	AppendDevicePathInstance (IN CONST EFI_DEVICE_PATH_PROTOCOL DevicePath OPTIONAL, IN CONST EFI_DEVICE_PATH_PROTOCOL DevicePathInstance OPTIONAL)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	GetNextDevicePathInstance (IN OUT EFI_DEVICE_PATH_PROTOCOL *DevicePath, OUT UINTN Size)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	CreateDeviceNode (IN UINT8 NodeType, IN UINT8 NodeSubType, IN UINT16 NodeLength)

BOOLEAN EFIAPI	IsDevicePathMultiInstance (IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath)

VOID *	UefiDevicePathLibLocateProtocol (EFI_GUID *ProtocolGuid)

CHAR16 *EFIAPI	ConvertDeviceNodeToText (IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode, IN BOOLEAN DisplayOnly, IN BOOLEAN AllowShortcuts)

CHAR16 *EFIAPI	ConvertDevicePathToText (IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, IN BOOLEAN DisplayOnly, IN BOOLEAN AllowShortcuts)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	ConvertTextToDeviceNode (IN CONST CHAR16 *TextDeviceNode)

EFI_DEVICE_PATH_PROTOCOL *EFIAPI	ConvertTextToDevicePath (IN CONST CHAR16 *TextDevicePath)

Variables
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

Detailed Description

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 varibles. Multi-instance device paths should never be placed on a Handle.

Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file UefiDevicePathLibOptionalDevicePathProtocol.c.

Function Documentation

◆ AppendDevicePath()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI AppendDevicePath	(	IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath	OPTIONAL,
		IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath	OPTIONAL
	)

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.

Parameters

FirstDevicePath	A pointer to a device path data structure.
SecondDevicePath	A pointer to a device path data structure.

Return values

NULL	If there is not enough memory for the newly allocated buffer.
NULL	If FirstDevicePath or SecondDevicePath is invalid.
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.

Definition at line 136 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ AppendDevicePathInstance()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI AppendDevicePathInstance	(	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath	OPTIONAL,
		IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance	OPTIONAL
	)

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.

Parameters

DevicePath	A pointer to a device path data structure.
DevicePathInstance	A pointer to a device path instance.

Returns: A pointer to the new device path.

Definition at line 215 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ AppendDevicePathNode()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI AppendDevicePathNode	(	IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath	OPTIONAL,
		IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode	OPTIONAL
	)

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.

Parameters

DevicePath	A pointer to a device path data structure.
DevicePathNode	A pointer to a single device path node.

Return values

NULL	If there is not enough memory for the new device path.
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.

Definition at line 178 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ ConvertDeviceNodeToText()

CHAR16 *EFIAPI ConvertDeviceNodeToText	(	IN CONST EFI_DEVICE_PATH_PROTOCOL *	DeviceNode,
		IN BOOLEAN	DisplayOnly,
		IN BOOLEAN	AllowShortcuts
	)

Converts a device node to its string representation.

Parameters

DeviceNode	A Pointer to the device node to be converted.
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.
AllowShortcuts	If AllowShortcuts is TRUE, then the shortcut forms of text representation for a device node can be used, where applicable.

Returns: A pointer to the allocated text representation of the device node or NULL if DeviceNode is NULL or there was insufficient memory.

Definition at line 375 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ ConvertDevicePathToText()

CHAR16 *EFIAPI ConvertDevicePathToText	(	IN CONST EFI_DEVICE_PATH_PROTOCOL *	DevicePath,
		IN BOOLEAN	DisplayOnly,
		IN BOOLEAN	AllowShortcuts
	)

Converts a device path to its text representation.

Parameters

DevicePath	A Pointer to the device to be converted.
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.
AllowShortcuts	If AllowShortcuts is TRUE, then the shortcut forms of text representation for a device node can be used, where applicable.

Returns: A pointer to the allocated text representation of the device path or NULL if DeviceNode is NULL or there was insufficient memory.

Definition at line 409 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ ConvertTextToDeviceNode()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI ConvertTextToDeviceNode ( IN CONST CHAR16 * TextDeviceNode )

Convert text to the binary representation of a device node.

Parameters

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.

Returns: A pointer to the EFI device node or NULL if TextDeviceNode is NULL or there was insufficient memory or text unsupported.

Definition at line 439 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ ConvertTextToDevicePath()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI ConvertTextToDevicePath ( IN CONST CHAR16 * TextDevicePath )

Convert text to the binary representation of a device path.

Parameters

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.

Returns: A pointer to the allocated device path or NULL if TextDeviceNode is NULL or there was insufficient memory.

Definition at line 468 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ CreateDeviceNode()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI CreateDeviceNode	(	IN UINT8	NodeType,
		IN UINT8	NodeSubType,
		IN UINT16	NodeLength
	)

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.

Parameters

NodeType	The device node type for the new device node.
NodeSubType	The device node sub-type for the new device node.
NodeLength	The length of the new device node.

Returns: The new device path.

Definition at line 290 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ DuplicateDevicePath()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI DuplicateDevicePath ( IN CONST EFI_DEVICE_PATH_PROTOCOL * 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.

Parameters

DevicePath A pointer to a device path data structure.

Return values

NULL	DevicePath is NULL or invalid.
Others	A pointer to the duplicated device path.

Definition at line 99 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ GetDevicePathSize()

UINTN EFIAPI GetDevicePathSize ( IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath )

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.

Parameters

DevicePath A pointer to a device path data structure.

Return values

0	If DevicePath is NULL or invalid.
Others	The size of a device path in bytes.

Definition at line 70 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ GetNextDevicePathInstance()

EFI_DEVICE_PATH_PROTOCOL *EFIAPI GetNextDevicePathInstance	(	IN OUT EFI_DEVICE_PATH_PROTOCOL **	DevicePath,
		OUT UINTN *	Size
	)

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().

Parameters

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.
Size	On output, this holds the size of the device path instance, in bytes or zero, if DevicePath is NULL.

Returns: A pointer to the current device path instance.

Definition at line 257 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ IsDevicePathMultiInstance()

BOOLEAN EFIAPI IsDevicePathMultiInstance ( IN CONST EFI_DEVICE_PATH_PROTOCOL * 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.

Parameters

DevicePath A pointer to a device path data structure.

Return values

TRUE	DevicePath is multi-instance.
FALSE	DevicePath is not multi-instance, or DevicePath is NULL or invalid.

Definition at line 320 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ UefiDevicePathLibLocateProtocol()

VOID * UefiDevicePathLibLocateProtocol ( EFI_GUID * ProtocolGuid )

Locate and return the protocol instance identified by the ProtocolGuid.

Parameters

ProtocolGuid The GUID of the protocol.

Returns: A pointer to the protocol instance or NULL when absent.

Definition at line 339 of file UefiDevicePathLibOptionalDevicePathProtocol.c.

◆ UefiDevicePathLibOptionalDevicePathProtocolConstructor()

EFI_STATUS EFIAPI UefiDevicePathLibOptionalDevicePathProtocolConstructor	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

The constructor function caches the pointer to DevicePathUtilites protocol, DevicePathToText protocol and DevicePathFromText protocol.

The constructor function locates these three protocols from protocol database. It will caches the pointer to local protocol instance if that operation fails and it will always return EFI_SUCCESS.

Parameters