From af1a266670d040d2f4083ff309d732d648afba2a Mon Sep 17 00:00:00 2001 From: Angelos Mouzakitis Date: Tue, 10 Oct 2023 14:33:42 +0000 Subject: Add submodule dependency files Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec --- .../UefiDevicePathLib/DevicePathUtilities.c | 897 +++++++++++++++++++++ 1 file changed, 897 insertions(+) create mode 100644 roms/edk2/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c (limited to 'roms/edk2/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c') diff --git a/roms/edk2/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c b/roms/edk2/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c new file mode 100644 index 000000000..9274ef8dd --- /dev/null +++ b/roms/edk2/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c @@ -0,0 +1,897 @@ +/** @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 varibles. Multi-instance device paths should never be placed + on a Handle. + + Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent + +**/ + +#include "UefiDevicePathLib.h" + +// +// 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 + } +}; + +/** + 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 + ) +{ + 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_UINTN; + } + + 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; + } + } + + // + // FilePath must be a NULL-terminated string. + // + if (DevicePathType (DevicePath) == MEDIA_DEVICE_PATH && + DevicePathSubType (DevicePath) == MEDIA_FILEPATH_DP && + *(CHAR16 *)((UINT8 *)DevicePath + NodeLength - 2) != 0) { + 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 +UefiDevicePathLibGetDevicePathSize ( + IN 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 * +EFIAPI +UefiDevicePathLibDuplicateDevicePath ( + IN 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 * +EFIAPI +UefiDevicePathLibAppendDevicePath ( + IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL + IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL + ) +{ + 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 = CopyMem (NewDevicePath, FirstDevicePath, Size1); + // + // Over write FirstDevicePath EndNode and do the copy + // + DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath + + (Size1 - END_DEVICE_PATH_LENGTH)); + CopyMem (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 * +EFIAPI +UefiDevicePathLibAppendDevicePathNode ( + IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL + IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL + ) +{ + 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 = CopyMem (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); + + FreePool (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 * +EFIAPI +UefiDevicePathLibAppendDevicePathInstance ( + IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL + IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL + ) +{ + 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 = CopyMem (NewDevicePath, DevicePath, SrcSize);; + + while (!IsDevicePathEnd (TempDevicePath)) { + TempDevicePath = NextDevicePathNode (TempDevicePath); + } + + TempDevicePath->SubType = END_INSTANCE_DEVICE_PATH_SUBTYPE; + TempDevicePath = NextDevicePathNode (TempDevicePath); + CopyMem (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 * +EFIAPI +UefiDevicePathLibGetNextDevicePathInstance ( + IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath, + OUT 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 * +EFIAPI +UefiDevicePathLibCreateDeviceNode ( + IN UINT8 NodeType, + IN UINT8 NodeSubType, + IN 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 +EFIAPI +UefiDevicePathLibIsDevicePathMultiInstance ( + IN 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 * +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; +} + -- cgit