| /** @file |
| Provides library functions to construct and parse UEFI Device Paths. |
| |
| This library provides defines, macros, and functions to help create and parse |
| EFI_DEVICE_PATH_PROTOCOL structures. |
| |
| Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR> |
| SPDX-License-Identifier: BSD-2-Clause-Patent |
| |
| **/ |
| |
| #ifndef __DEVICE_PATH_LIB_H__ |
| #define __DEVICE_PATH_LIB_H__ |
| |
| #define END_DEVICE_PATH_LENGTH (sizeof (EFI_DEVICE_PATH_PROTOCOL)) |
| |
| /** |
| 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 |
| EFIAPI |
| IsDevicePathValid ( |
| IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, |
| IN UINTN MaxSize |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 >= 0x10000, 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 * |
| EFIAPI |
| DuplicateDevicePath ( |
| IN CONST EFI_DEVICE_PATH_PROTOCOL *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 |
| ); |
| |
| /** |
| 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 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 |
| ); |
| |
| /** |
| 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 secified 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 |
| ); |
| |
| /** |
| 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 * |
| EFIAPI |
| GetNextDevicePathInstance ( |
| IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath, |
| OUT UINTN *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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| /** |
| 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 |
| ); |
| |
| #endif |