DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlNodeInterface.c - edk2 - Git at Google

 /** @file
   AML Node Interface.

   Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>

   SPDX-License-Identifier: BSD-2-Clause-Patent
 **/

 #include <AmlNodeDefines.h>

 #include <AmlCoreInterface.h>
 #include <ResourceData/AmlResourceData.h>
 #include <String/AmlString.h>
 #include <Tree/AmlNode.h>
 #include <Tree/AmlTree.h>
 #include <Utils/AmlUtility.h>

 /** Returns the tree node type (Root/Object/Data).

   @param [in] Node  Pointer to a Node.

   @return The node type.
            EAmlNodeUnknown if invalid parameter.
 **/
 EAML_NODE_TYPE
 EFIAPI
 AmlGetNodeType (
   IN  AML_NODE_HEADER  *Node
   )
 {
   if (!IS_AML_NODE_VALID (Node)) {
     ASSERT (0);
     return EAmlNodeUnknown;
   }

   return Node->NodeType;
 }

 /** Get the RootNode information.
     The Node must be a root node.

   @param  [in]  RootNode          Pointer to a root node.
   @param  [out] SdtHeaderBuffer   Buffer to copy the ACPI DSDT/SSDT header to.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlGetRootNodeInfo (
   IN  AML_ROOT_NODE                *RootNode,
   OUT EFI_ACPI_DESCRIPTION_HEADER  *SdtHeaderBuffer
   )
 {
   if (!IS_AML_ROOT_NODE (RootNode)  ||
       (SdtHeaderBuffer == NULL))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   CopyMem (
     SdtHeaderBuffer,
     RootNode->SdtHeader,
     sizeof (EFI_ACPI_DESCRIPTION_HEADER)
     );

   return EFI_SUCCESS;
 }

 /** Get the ObjectNode information.
     The Node must be an object node.

   @ingroup NodeInterfaceApi

   @param  [in]  ObjectNode        Pointer to an object node.
   @param  [out] OpCode            Pointer holding the OpCode.
                                   Optional, can be NULL.
   @param  [out] SubOpCode         Pointer holding the SubOpCode.
                                   Optional, can be NULL.
   @param  [out] PkgLen            Pointer holding the PkgLen.
                                   The PkgLen is 0 for nodes
                                   not having the Pkglen attribute.
                                   Optional, can be NULL.
   @param  [out] IsNameSpaceNode   Pointer holding TRUE if the node is defining
                                   or changing the NameSpace scope.
                                   E.g.: The "Name ()" and "Scope ()" ASL
                                   statements add/modify the NameSpace scope.
                                   Their corresponding node are NameSpace nodes.
                                   Optional, can be NULL.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlGetObjectNodeInfo (
   IN  AML_OBJECT_NODE  *ObjectNode,
   OUT UINT8            *OpCode            OPTIONAL,
   OUT UINT8            *SubOpCode         OPTIONAL,
   OUT UINT32           *PkgLen            OPTIONAL,
   OUT BOOLEAN          *IsNameSpaceNode   OPTIONAL
   )
 {
   if (!IS_AML_OBJECT_NODE (ObjectNode)) {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   if (OpCode != NULL) {
     *OpCode = ObjectNode->AmlByteEncoding->OpCode;
   }

   if (SubOpCode != NULL) {
     *SubOpCode = ObjectNode->AmlByteEncoding->SubOpCode;
   }

   if (PkgLen != NULL) {
     *PkgLen = ObjectNode->PkgLen;
   }

   if (IsNameSpaceNode != NULL) {
     *IsNameSpaceNode = AmlNodeHasAttribute (ObjectNode, AML_IN_NAMESPACE);
   }

   return EFI_SUCCESS;
 }

 /** Returns the count of the fixed arguments for the input Node.

   @param  [in]  Node  Pointer to an object node.

   @return Number of fixed arguments of the object node.
           Return 0 if the node is not an object node.
 **/
 UINT8
 AmlGetFixedArgumentCount (
   IN  AML_OBJECT_NODE  *Node
   )
 {
   if (IS_AML_OBJECT_NODE (Node) &&
       (Node->AmlByteEncoding != NULL))
   {
     return (UINT8)Node->AmlByteEncoding->MaxIndex;
   }

   return 0;
 }

 /** Get the data type of the DataNode.
     The Node must be a data node.

   @param  [in]  DataNode  Pointer to a data node.
   @param  [out] DataType  Pointer holding the data type of the data buffer.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlGetNodeDataType (
   IN  AML_DATA_NODE        *DataNode,
   OUT EAML_NODE_DATA_TYPE  *DataType
   )
 {
   if (!IS_AML_DATA_NODE (DataNode)  ||
       (DataType == NULL))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   *DataType = DataNode->DataType;

   return EFI_SUCCESS;
 }

 /** Get the descriptor Id of the resource data element
     contained in the DataNode.

   The Node must be a data node.
   The Node must have the resource data type, i.e. have the
   EAmlNodeDataTypeResourceData data type.

   @param  [in]  DataNode          Pointer to a data node containing a
                                   resource data element.
   @param  [out] ResourceDataType  Pointer holding the descriptor Id of
                                   the resource data.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlGetResourceDataType (
   IN  AML_DATA_NODE  *DataNode,
   OUT AML_RD_HEADER  *ResourceDataType
   )
 {
   if (!IS_AML_DATA_NODE (DataNode)  ||
       (ResourceDataType == NULL)    ||
       (DataNode->DataType != EAmlNodeDataTypeResourceData))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   *ResourceDataType = AmlRdGetDescId (DataNode->Buffer);

   return EFI_SUCCESS;
 }

 /** Get the data buffer and size of the DataNode.
     The Node must be a data node.

   BufferSize is always updated to the size of buffer of the DataNode.

   If:
    - the content of BufferSize is >= to the DataNode's buffer size;
    - Buffer is not NULL;
   then copy the content of the DataNode's buffer in Buffer.

   @param  [in]      DataNode      Pointer to a data node.
   @param  [out]     Buffer        Buffer to write the data to.
                                   Optional, if NULL, only update BufferSize.
   @param  [in, out] BufferSize    Pointer holding:
                                    - At entry, the size of the Buffer;
                                    - At exit, the size of the DataNode's
                                      buffer size.

   @retval EFI_SUCCESS           The function completed successfully.
   @retval EFI_INVALID_PARAMETER Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlGetDataNodeBuffer (
   IN      AML_DATA_NODE  *DataNode,
   OUT UINT8              *Buffer        OPTIONAL,
   IN  OUT UINT32         *BufferSize
   )
 {
   if (!IS_AML_DATA_NODE (DataNode) ||
       (BufferSize == NULL))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   if ((*BufferSize >= DataNode->Size)  &&
       (Buffer != NULL))
   {
     CopyMem (Buffer, DataNode->Buffer, DataNode->Size);
   }

   *BufferSize = DataNode->Size;

   return EFI_SUCCESS;
 }

 /** Update the ACPI DSDT/SSDT table header.

   The input SdtHeader information is copied to the tree RootNode.
   The table Length field is automatically updated.
   The checksum field is only updated when serializing the tree.

   @param  [in]  RootNode    Pointer to a root node.
   @param  [in]  SdtHeader   Pointer to an ACPI DSDT/SSDT table header.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlUpdateRootNode (
   IN        AML_ROOT_NODE                *RootNode,
   IN  CONST EFI_ACPI_DESCRIPTION_HEADER  *SdtHeader
   )
 {
   EFI_STATUS  Status;
   UINT32      Length;

   if (!IS_AML_ROOT_NODE (RootNode)  ||
       (SdtHeader == NULL)           ||
       ((SdtHeader->Signature !=
         EFI_ACPI_6_3_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) &&
        (SdtHeader->Signature !=
         EFI_ACPI_6_3_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE)))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   CopyMem (
     RootNode->SdtHeader,
     SdtHeader,
     sizeof (EFI_ACPI_DESCRIPTION_HEADER)
     );

   // Update the Length field.
   Status = AmlComputeSize ((AML_NODE_HEADER *)RootNode, &Length);
   if (EFI_ERROR (Status)) {
     ASSERT (0);
     return Status;
   }

   RootNode->SdtHeader->Length = Length +
                                 (UINT32)sizeof (EFI_ACPI_DESCRIPTION_HEADER);

   return Status;
 }

 /** Update an object node representing an integer with a new value.

   The object node must have one of the following OpCodes:
    - AML_BYTE_PREFIX
    - AML_WORD_PREFIX
    - AML_DWORD_PREFIX
    - AML_QWORD_PREFIX
    - AML_ZERO_OP
    - AML_ONE_OP

   The following OpCode is not supported:
    - AML_ONES_OP

   @param  [in] IntegerOpNode   Pointer an object node containing an integer.
                                Must not be an object node with an AML_ONES_OP
                                OpCode.
   @param  [in] NewInteger      New integer value to set.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
 **/
 EFI_STATUS
 EFIAPI
 AmlUpdateInteger (
   IN  AML_OBJECT_NODE  *IntegerOpNode,
   IN  UINT64           NewInteger
   )
 {
   EFI_STATUS  Status;

   INT8  ValueWidthDiff;

   if (!IS_AML_OBJECT_NODE (IntegerOpNode)     ||
       (!IsIntegerNode (IntegerOpNode)         &&
        !IsSpecialIntegerNode (IntegerOpNode)) ||
       AmlNodeCompareOpCode (IntegerOpNode, AML_ONES_OP, 0))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   Status = AmlNodeSetIntegerValue (IntegerOpNode, NewInteger, &ValueWidthDiff);
   if (EFI_ERROR (Status)) {
     ASSERT (0);
     return Status;
   }

   // If the new size is different from the old size, propagate the new size.
   if (ValueWidthDiff != 0) {
     // Propagate the information.
     Status = AmlPropagateInformation (
                (AML_NODE_HEADER *)IntegerOpNode,
                (ValueWidthDiff > 0) ? TRUE : FALSE,
                ABS (ValueWidthDiff),
                0
                );
     if (EFI_ERROR (Status)) {
       ASSERT (0);
     }
   }

   return Status;
 }

 /** Update the buffer of a data node.

   Note: The data type of the buffer's content must match the data type of the
         DataNode. This is a hard restriction to prevent undesired behaviour.

   @param  [in]  DataNode  Pointer to a data node.
   @param  [in]  DataType  Data type of the Buffer's content.
   @param  [in]  Buffer    Buffer containing the new data. The content of
                           the Buffer is copied.
   @param  [in]  Size      Size of the Buffer.

   @retval EFI_SUCCESS             The function completed successfully.
   @retval EFI_INVALID_PARAMETER   Invalid parameter.
   @retval EFI_UNSUPPORTED         Operation not supporter.
 **/
 EFI_STATUS
 EFIAPI
 AmlUpdateDataNode (
   IN  AML_DATA_NODE        *DataNode,
   IN  EAML_NODE_DATA_TYPE  DataType,
   IN  UINT8                *Buffer,
   IN  UINT32               Size
   )
 {
   EFI_STATUS  Status;

   UINT32               ExpectedSize;
   AML_OBJECT_NODE      *ParentNode;
   EAML_NODE_DATA_TYPE  ExpectedArgType;
   EAML_PARSE_INDEX     Index;

   if (!IS_AML_DATA_NODE (DataNode)      ||
       (DataType > EAmlNodeDataTypeMax)  ||
       (Buffer == NULL)                  ||
       (Size == 0))
   {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   ParentNode = (AML_OBJECT_NODE *)AmlGetParent ((AML_NODE_HEADER *)DataNode);
   if (!IS_AML_OBJECT_NODE (ParentNode)) {
     ASSERT (0);
     return EFI_INVALID_PARAMETER;
   }

   // The NewNode and OldNode must have the same type.
   // We do not allow to change the argument type of a data node.
   // If required, the initial ASL template should be modified
   // accordingly.
   // It is however possible to interchange a raw buffer and a
   // resource data element, since raw data can be misinterpreted
   // as a resource data element.
   ExpectedArgType = DataNode->DataType;
   if ((ExpectedArgType != DataType)                         &&
       (((ExpectedArgType != EAmlNodeDataTypeRaw)            &&
         (ExpectedArgType != EAmlNodeDataTypeResourceData))  ||
        ((DataType != EAmlNodeDataTypeRaw)                   &&
         (DataType != EAmlNodeDataTypeResourceData))))
   {
     ASSERT (0);
     return EFI_UNSUPPORTED;
   }

   // Perform some compatibility checks.
   switch (DataType) {
     case EAmlNodeDataTypeNameString:
     {
       // Check the name contained in the Buffer is an AML name
       // with the right size.
       Status = AmlGetNameStringSize ((CONST CHAR8 *)Buffer, &ExpectedSize);
       if (EFI_ERROR (Status)  ||
           (Size != ExpectedSize))
       {
         ASSERT (0);
         return Status;
       }

       break;
     }
     case EAmlNodeDataTypeString:
     {
       ExpectedSize = 0;
       while (ExpectedSize < Size) {
         // Cf ACPI 6.3 specification 20.2.3 Data Objects Encoding.
         // AsciiCharList := Nothing | <AsciiChar AsciiCharList>
         // AsciiChar := 0x01 - 0x7F
         // NullChar := 0x00
         if (Buffer[ExpectedSize] > 0x7F) {
           ASSERT (0);
           return EFI_INVALID_PARAMETER;
         }

         ExpectedSize++;
       }

       if (ExpectedSize != Size) {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       break;
     }
     case EAmlNodeDataTypeUInt:
     {
       if (AmlIsNodeFixedArgument ((CONST AML_NODE_HEADER *)DataNode, &Index)) {
         if ((ParentNode->AmlByteEncoding == NULL) ||
             (ParentNode->AmlByteEncoding->Format == NULL))
         {
           ASSERT (0);
           return EFI_INVALID_PARAMETER;
         }

         // It is not possible to change the size of a fixed length UintX.
         // E.g. for PackageOp the first fixed argument is of type EAmlUInt8
         // and represents the count of elements. This type cannot be changed.
         if ((ParentNode->AmlByteEncoding->Format[Index] != EAmlObject) &&
             (DataNode->Size != Size))
         {
           ASSERT (0);
           return EFI_UNSUPPORTED;
         }
       }

       break;
     }
     case EAmlNodeDataTypeRaw:
     {
       // Check if the parent node has the byte list flag set.
       if (!AmlNodeHasAttribute (ParentNode, AML_HAS_BYTE_LIST)) {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       break;
     }
     case EAmlNodeDataTypeResourceData:
     {
       // The resource data can be either small or large resource data.
       // Small resource data must be at least 1 byte.
       // Large resource data must be at least as long as the header
       // of a large resource data.
       if (AML_RD_IS_LARGE (Buffer)  &&
           (Size < sizeof (ACPI_LARGE_RESOURCE_HEADER)))
       {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       // Check if the parent node has the byte list flag set.
       if (!AmlNodeHasAttribute (ParentNode, AML_HAS_BYTE_LIST)) {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       // Check the size of the buffer is equal to the resource data size
       // encoded in the input buffer.
       ExpectedSize = AmlRdGetSize (Buffer);
       if (ExpectedSize != Size) {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       Status = AmlSetRdListCheckSum (ParentNode, 0);
       if (EFI_ERROR (Status)) {
         ASSERT (0);
         return Status;
       }

       break;
     }
     case EAmlNodeDataTypeFieldPkgLen:
     {
       // Check the parent is a FieldNamed field element.
       if (!AmlNodeCompareOpCode (ParentNode, AML_FIELD_NAMED_OP, 0)) {
         ASSERT (0);
         return EFI_INVALID_PARAMETER;
       }

       break;
     }
     // None and reserved types.
     default:
     {
       ASSERT (0);
       return EFI_INVALID_PARAMETER;
       break;
     }
   } // switch

   // If the new size is different from the old size, propagate the new size.
   if (DataNode->Size != Size) {
     // Propagate the information.
     Status = AmlPropagateInformation (
                DataNode->NodeHeader.Parent,
                (Size > DataNode->Size) ? TRUE : FALSE,
                (Size > DataNode->Size) ?
                (Size - DataNode->Size) :
                (DataNode->Size - Size),
                0
                );
     if (EFI_ERROR (Status)) {
       ASSERT (0);
       return Status;
     }

     // Free the old DataNode buffer and allocate a new buffer to store the
     // new data.
     FreePool (DataNode->Buffer);
     DataNode->Buffer = AllocateZeroPool (Size);
     if (DataNode->Buffer == NULL) {
       ASSERT (0);
       return EFI_OUT_OF_RESOURCES;
     }

     DataNode->Size = Size;
   }

   CopyMem (DataNode->Buffer, Buffer, Size);

   return EFI_SUCCESS;
 }
	/** @file
	AML Node Interface.

	Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>

	SPDX-License-Identifier: BSD-2-Clause-Patent
	**/

	#include <AmlNodeDefines.h>

	#include <AmlCoreInterface.h>
	#include <ResourceData/AmlResourceData.h>
	#include <String/AmlString.h>
	#include <Tree/AmlNode.h>
	#include <Tree/AmlTree.h>
	#include <Utils/AmlUtility.h>

	/** Returns the tree node type (Root/Object/Data).

	@param [in] Node Pointer to a Node.

	@return The node type.
	EAmlNodeUnknown if invalid parameter.
	**/
	EAML_NODE_TYPE
	EFIAPI
	AmlGetNodeType (
	IN AML_NODE_HEADER *Node
	)
	{
	if (!IS_AML_NODE_VALID (Node)) {
	ASSERT (0);
	return EAmlNodeUnknown;
	}

	return Node->NodeType;
	}

	/** Get the RootNode information.
	The Node must be a root node.

	@param [in] RootNode Pointer to a root node.
	@param [out] SdtHeaderBuffer Buffer to copy the ACPI DSDT/SSDT header to.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlGetRootNodeInfo (
	IN AML_ROOT_NODE *RootNode,
	OUT EFI_ACPI_DESCRIPTION_HEADER *SdtHeaderBuffer
	)
	{
	if (!IS_AML_ROOT_NODE (RootNode) \|\|
	(SdtHeaderBuffer == NULL))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	CopyMem (
	SdtHeaderBuffer,
	RootNode->SdtHeader,
	sizeof (EFI_ACPI_DESCRIPTION_HEADER)
	);

	return EFI_SUCCESS;
	}

	/** Get the ObjectNode information.
	The Node must be an object node.

	@ingroup NodeInterfaceApi

	@param [in] ObjectNode Pointer to an object node.
	@param [out] OpCode Pointer holding the OpCode.
	Optional, can be NULL.
	@param [out] SubOpCode Pointer holding the SubOpCode.
	Optional, can be NULL.
	@param [out] PkgLen Pointer holding the PkgLen.
	The PkgLen is 0 for nodes
	not having the Pkglen attribute.
	Optional, can be NULL.
	@param [out] IsNameSpaceNode Pointer holding TRUE if the node is defining
	or changing the NameSpace scope.
	E.g.: The "Name ()" and "Scope ()" ASL
	statements add/modify the NameSpace scope.
	Their corresponding node are NameSpace nodes.
	Optional, can be NULL.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlGetObjectNodeInfo (
	IN AML_OBJECT_NODE *ObjectNode,
	OUT UINT8 *OpCode OPTIONAL,
	OUT UINT8 *SubOpCode OPTIONAL,
	OUT UINT32 *PkgLen OPTIONAL,
	OUT BOOLEAN *IsNameSpaceNode OPTIONAL
	)
	{
	if (!IS_AML_OBJECT_NODE (ObjectNode)) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	if (OpCode != NULL) {
	*OpCode = ObjectNode->AmlByteEncoding->OpCode;
	}

	if (SubOpCode != NULL) {
	*SubOpCode = ObjectNode->AmlByteEncoding->SubOpCode;
	}

	if (PkgLen != NULL) {
	*PkgLen = ObjectNode->PkgLen;
	}

	if (IsNameSpaceNode != NULL) {
	*IsNameSpaceNode = AmlNodeHasAttribute (ObjectNode, AML_IN_NAMESPACE);
	}

	return EFI_SUCCESS;
	}

	/** Returns the count of the fixed arguments for the input Node.

	@param [in] Node Pointer to an object node.

	@return Number of fixed arguments of the object node.
	Return 0 if the node is not an object node.
	**/
	UINT8
	AmlGetFixedArgumentCount (
	IN AML_OBJECT_NODE *Node
	)
	{
	if (IS_AML_OBJECT_NODE (Node) &&
	(Node->AmlByteEncoding != NULL))
	{
	return (UINT8)Node->AmlByteEncoding->MaxIndex;
	}

	return 0;
	}

	/** Get the data type of the DataNode.
	The Node must be a data node.

	@param [in] DataNode Pointer to a data node.
	@param [out] DataType Pointer holding the data type of the data buffer.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlGetNodeDataType (
	IN AML_DATA_NODE *DataNode,
	OUT EAML_NODE_DATA_TYPE *DataType
	)
	{
	if (!IS_AML_DATA_NODE (DataNode) \|\|
	(DataType == NULL))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	*DataType = DataNode->DataType;

	return EFI_SUCCESS;
	}

	/** Get the descriptor Id of the resource data element
	contained in the DataNode.

	The Node must be a data node.
	The Node must have the resource data type, i.e. have the
	EAmlNodeDataTypeResourceData data type.

	@param [in] DataNode Pointer to a data node containing a
	resource data element.
	@param [out] ResourceDataType Pointer holding the descriptor Id of
	the resource data.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlGetResourceDataType (
	IN AML_DATA_NODE *DataNode,
	OUT AML_RD_HEADER *ResourceDataType
	)
	{
	if (!IS_AML_DATA_NODE (DataNode) \|\|
	(ResourceDataType == NULL) \|\|
	(DataNode->DataType != EAmlNodeDataTypeResourceData))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	*ResourceDataType = AmlRdGetDescId (DataNode->Buffer);

	return EFI_SUCCESS;
	}

	/** Get the data buffer and size of the DataNode.
	The Node must be a data node.

	BufferSize is always updated to the size of buffer of the DataNode.

	If:
	- the content of BufferSize is >= to the DataNode's buffer size;
	- Buffer is not NULL;
	then copy the content of the DataNode's buffer in Buffer.

	@param [in] DataNode Pointer to a data node.
	@param [out] Buffer Buffer to write the data to.
	Optional, if NULL, only update BufferSize.
	@param [in, out] BufferSize Pointer holding:
	- At entry, the size of the Buffer;
	- At exit, the size of the DataNode's
	buffer size.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlGetDataNodeBuffer (
	IN AML_DATA_NODE *DataNode,
	OUT UINT8 *Buffer OPTIONAL,
	IN OUT UINT32 *BufferSize
	)
	{
	if (!IS_AML_DATA_NODE (DataNode) \|\|
	(BufferSize == NULL))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	if ((*BufferSize >= DataNode->Size) &&
	(Buffer != NULL))
	{
	CopyMem (Buffer, DataNode->Buffer, DataNode->Size);
	}

	*BufferSize = DataNode->Size;

	return EFI_SUCCESS;
	}

	/** Update the ACPI DSDT/SSDT table header.

	The input SdtHeader information is copied to the tree RootNode.
	The table Length field is automatically updated.
	The checksum field is only updated when serializing the tree.

	@param [in] RootNode Pointer to a root node.
	@param [in] SdtHeader Pointer to an ACPI DSDT/SSDT table header.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlUpdateRootNode (
	IN AML_ROOT_NODE *RootNode,
	IN CONST EFI_ACPI_DESCRIPTION_HEADER *SdtHeader
	)
	{
	EFI_STATUS Status;
	UINT32 Length;

	if (!IS_AML_ROOT_NODE (RootNode) \|\|
	(SdtHeader == NULL) \|\|
	((SdtHeader->Signature !=
	EFI_ACPI_6_3_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) &&
	(SdtHeader->Signature !=
	EFI_ACPI_6_3_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE)))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	CopyMem (
	RootNode->SdtHeader,
	SdtHeader,
	sizeof (EFI_ACPI_DESCRIPTION_HEADER)
	);

	// Update the Length field.
	Status = AmlComputeSize ((AML_NODE_HEADER *)RootNode, &Length);
	if (EFI_ERROR (Status)) {
	ASSERT (0);
	return Status;
	}

	RootNode->SdtHeader->Length = Length +
	(UINT32)sizeof (EFI_ACPI_DESCRIPTION_HEADER);

	return Status;
	}

	/** Update an object node representing an integer with a new value.

	The object node must have one of the following OpCodes:
	- AML_BYTE_PREFIX
	- AML_WORD_PREFIX
	- AML_DWORD_PREFIX
	- AML_QWORD_PREFIX
	- AML_ZERO_OP
	- AML_ONE_OP

	The following OpCode is not supported:
	- AML_ONES_OP

	@param [in] IntegerOpNode Pointer an object node containing an integer.
	Must not be an object node with an AML_ONES_OP
	OpCode.
	@param [in] NewInteger New integer value to set.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	**/
	EFI_STATUS
	EFIAPI
	AmlUpdateInteger (
	IN AML_OBJECT_NODE *IntegerOpNode,
	IN UINT64 NewInteger
	)
	{
	EFI_STATUS Status;

	INT8 ValueWidthDiff;

	if (!IS_AML_OBJECT_NODE (IntegerOpNode) \|\|
	(!IsIntegerNode (IntegerOpNode) &&
	!IsSpecialIntegerNode (IntegerOpNode)) \|\|
	AmlNodeCompareOpCode (IntegerOpNode, AML_ONES_OP, 0))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	Status = AmlNodeSetIntegerValue (IntegerOpNode, NewInteger, &ValueWidthDiff);
	if (EFI_ERROR (Status)) {
	ASSERT (0);
	return Status;
	}

	// If the new size is different from the old size, propagate the new size.
	if (ValueWidthDiff != 0) {
	// Propagate the information.
	Status = AmlPropagateInformation (
	(AML_NODE_HEADER *)IntegerOpNode,
	(ValueWidthDiff > 0) ? TRUE : FALSE,
	ABS (ValueWidthDiff),
	0
	);
	if (EFI_ERROR (Status)) {
	ASSERT (0);
	}
	}

	return Status;
	}

	/** Update the buffer of a data node.

	Note: The data type of the buffer's content must match the data type of the
	DataNode. This is a hard restriction to prevent undesired behaviour.

	@param [in] DataNode Pointer to a data node.
	@param [in] DataType Data type of the Buffer's content.
	@param [in] Buffer Buffer containing the new data. The content of
	the Buffer is copied.
	@param [in] Size Size of the Buffer.

	@retval EFI_SUCCESS The function completed successfully.
	@retval EFI_INVALID_PARAMETER Invalid parameter.
	@retval EFI_UNSUPPORTED Operation not supporter.
	**/
	EFI_STATUS
	EFIAPI
	AmlUpdateDataNode (
	IN AML_DATA_NODE *DataNode,
	IN EAML_NODE_DATA_TYPE DataType,
	IN UINT8 *Buffer,
	IN UINT32 Size
	)
	{
	EFI_STATUS Status;

	UINT32 ExpectedSize;
	AML_OBJECT_NODE *ParentNode;
	EAML_NODE_DATA_TYPE ExpectedArgType;
	EAML_PARSE_INDEX Index;

	if (!IS_AML_DATA_NODE (DataNode) \|\|
	(DataType > EAmlNodeDataTypeMax) \|\|
	(Buffer == NULL) \|\|
	(Size == 0))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	ParentNode = (AML_OBJECT_NODE )AmlGetParent ((AML_NODE_HEADER )DataNode);
	if (!IS_AML_OBJECT_NODE (ParentNode)) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	// The NewNode and OldNode must have the same type.
	// We do not allow to change the argument type of a data node.
	// If required, the initial ASL template should be modified
	// accordingly.
	// It is however possible to interchange a raw buffer and a
	// resource data element, since raw data can be misinterpreted
	// as a resource data element.
	ExpectedArgType = DataNode->DataType;
	if ((ExpectedArgType != DataType) &&
	(((ExpectedArgType != EAmlNodeDataTypeRaw) &&
	(ExpectedArgType != EAmlNodeDataTypeResourceData)) \|\|
	((DataType != EAmlNodeDataTypeRaw) &&
	(DataType != EAmlNodeDataTypeResourceData))))
	{
	ASSERT (0);
	return EFI_UNSUPPORTED;
	}

	// Perform some compatibility checks.
	switch (DataType) {
	case EAmlNodeDataTypeNameString:
	{
	// Check the name contained in the Buffer is an AML name
	// with the right size.
	Status = AmlGetNameStringSize ((CONST CHAR8 *)Buffer, &ExpectedSize);
	if (EFI_ERROR (Status) \|\|
	(Size != ExpectedSize))
	{
	ASSERT (0);
	return Status;
	}

	break;
	}
	case EAmlNodeDataTypeString:
	{
	ExpectedSize = 0;
	while (ExpectedSize < Size) {
	// Cf ACPI 6.3 specification 20.2.3 Data Objects Encoding.
	// AsciiCharList := Nothing \| <AsciiChar AsciiCharList>
	// AsciiChar := 0x01 - 0x7F
	// NullChar := 0x00
	if (Buffer[ExpectedSize] > 0x7F) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	ExpectedSize++;
	}

	if (ExpectedSize != Size) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	break;
	}
	case EAmlNodeDataTypeUInt:
	{
	if (AmlIsNodeFixedArgument ((CONST AML_NODE_HEADER *)DataNode, &Index)) {
	if ((ParentNode->AmlByteEncoding == NULL) \|\|
	(ParentNode->AmlByteEncoding->Format == NULL))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	// It is not possible to change the size of a fixed length UintX.
	// E.g. for PackageOp the first fixed argument is of type EAmlUInt8
	// and represents the count of elements. This type cannot be changed.
	if ((ParentNode->AmlByteEncoding->Format[Index] != EAmlObject) &&
	(DataNode->Size != Size))
	{
	ASSERT (0);
	return EFI_UNSUPPORTED;
	}
	}

	break;
	}
	case EAmlNodeDataTypeRaw:
	{
	// Check if the parent node has the byte list flag set.
	if (!AmlNodeHasAttribute (ParentNode, AML_HAS_BYTE_LIST)) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	break;
	}
	case EAmlNodeDataTypeResourceData:
	{
	// The resource data can be either small or large resource data.
	// Small resource data must be at least 1 byte.
	// Large resource data must be at least as long as the header
	// of a large resource data.
	if (AML_RD_IS_LARGE (Buffer) &&
	(Size < sizeof (ACPI_LARGE_RESOURCE_HEADER)))
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	// Check if the parent node has the byte list flag set.
	if (!AmlNodeHasAttribute (ParentNode, AML_HAS_BYTE_LIST)) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	// Check the size of the buffer is equal to the resource data size
	// encoded in the input buffer.
	ExpectedSize = AmlRdGetSize (Buffer);
	if (ExpectedSize != Size) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	Status = AmlSetRdListCheckSum (ParentNode, 0);
	if (EFI_ERROR (Status)) {
	ASSERT (0);
	return Status;
	}

	break;
	}
	case EAmlNodeDataTypeFieldPkgLen:
	{
	// Check the parent is a FieldNamed field element.
	if (!AmlNodeCompareOpCode (ParentNode, AML_FIELD_NAMED_OP, 0)) {
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	}

	break;
	}
	// None and reserved types.
	default:
	{
	ASSERT (0);
	return EFI_INVALID_PARAMETER;
	break;
	}
	} // switch

	// If the new size is different from the old size, propagate the new size.
	if (DataNode->Size != Size) {
	// Propagate the information.
	Status = AmlPropagateInformation (
	DataNode->NodeHeader.Parent,
	(Size > DataNode->Size) ? TRUE : FALSE,
	(Size > DataNode->Size) ?
	(Size - DataNode->Size) :
	(DataNode->Size - Size),
	0
	);
	if (EFI_ERROR (Status)) {
	ASSERT (0);
	return Status;
	}

	// Free the old DataNode buffer and allocate a new buffer to store the
	// new data.
	FreePool (DataNode->Buffer);
	DataNode->Buffer = AllocateZeroPool (Size);
	if (DataNode->Buffer == NULL) {
	ASSERT (0);
	return EFI_OUT_OF_RESOURCES;
	}

	DataNode->Size = Size;
	}

	CopyMem (DataNode->Buffer, Buffer, Size);

	return EFI_SUCCESS;
	}