[PATCH v1 23/30] DynamicTablesPkg: AML Core interface

["Sami Mujawar" <sami.mujawar@arm.com>]

From: Pierre Gondois <pierre.gondois@arm.com>

AML Core interface APIs are internal APIs of the
AmlLib library. These APIs can be used to:
 - Create/Delete/Clone an AML tree/node
 - Get/update Fixed and Variable arguments
 - Serialize an AML tree.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
---
 DynamicTablesPkg/Library/Common/AmlLib/AmlCoreInterface.h | 767 ++++++++++++++++++++
 1 file changed, 767 insertions(+)

diff --git a/DynamicTablesPkg/Library/Common/AmlLib/AmlCoreInterface.h b/DynamicTablesPkg/Library/Common/AmlLib/AmlCoreInterface.h
new file mode 100644
index 0000000000000000000000000000000000000000..9905cfe551b50eccb3576ff9bdb6a1b582199601
--- /dev/null
+++ b/DynamicTablesPkg/Library/Common/AmlLib/AmlCoreInterface.h
@@ -0,0 +1,767 @@
+/** @file
+  AML Core Interface.
+
+  Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef AML_CORE_INTERFACE_H_
+#define AML_CORE_INTERFACE_H_
+
+/* This header file does not include internal Node definition,
+   i.e. AML_ROOT_NODE, AML_OBJECT_NODE, etc. The node definitions
+   must be included by the caller file. The function prototypes must
+   only expose AML_NODE_HANDLE, AML_ROOT_NODE_HANDLE, etc. node
+   definitions.
+   This allows to keep the functions defined here both internal and
+   potentially external. If necessary, any function of this file can
+   be exposed externally.
+   The Api folder is internal to the AmlLib, but should only use these
+   functions. They provide a "safe" way to interact with the AmlLib.
+*/
+
+#include <AmlDefines.h>
+#include <Include/Library/AmlLib/AmlLib.h>
+#include <ResourceData/AmlResourceData.h>
+
+/**
+  @defgroup CoreApis Core APIs
+  @ingroup AMLLib
+  @{
+    Core APIs are the main APIs of the library. They allow to:
+     - Create an AML tree;
+     - Delete an AML tree;
+     - Clone an AML tree/node;
+     - Serialize an AML tree (convert the tree to a DSDT/SSDT table).
+  @}
+*/
+
+/** Serialize a tree to create a DSDT/SSDT table.
+
+  If:
+   - the content of BufferSize is >= to the size needed to serialize the
+     definition block;
+   - Buffer is not NULL;
+   first serialize the ACPI DSDT/SSDT header from the root node,
+   then serialize the AML blob from the rest of the tree.
+
+  The content of BufferSize is always updated to the size needed to
+  serialize the definition block.
+
+  @ingroup CoreApis
+
+  @param  [in]      RootNode    Pointer to a root node.
+  @param  [in]      Buffer      Buffer to write the DSDT/SSDT table to.
+                                If Buffer is NULL, the size needed to
+                                serialize the DSDT/SSDT table is returned
+                                in BufferSize.
+  @param  [in, out] BufferSize  Pointer holding the size of the Buffer.
+                                Its content is always updated to the size
+                                needed to serialize the DSDT/SSDT table.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_BUFFER_TOO_SMALL    No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlSerializeTree (
+  IN      AML_ROOT_NODE_HANDLE    RootNode,
+  IN      UINT8                 * Buffer,     OPTIONAL
+  IN  OUT UINT32                * BufferSize
+  );
+
+/** Clone a node.
+
+  This function does not clone the children nodes.
+  The cloned node returned is not attached to any tree.
+
+  @ingroup CoreApis
+
+  @param  [in]  Node        Pointer to a node.
+  @param  [out] ClonedNode  Pointer holding the cloned node.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_OUT_OF_RESOURCES    Could not allocate memory.
+**/
+EFI_STATUS
+EFIAPI
+AmlCloneNode (
+  IN  AML_NODE_HANDLE   Node,
+  OUT AML_NODE_HANDLE * ClonedNode
+  );
+
+/**
+  @defgroup TreeModificationApis Tree modification APIs
+  @ingroup AMLLib
+  @{
+    Tree modification APIs allow to add/remove/replace nodes that are in a
+    variable list of arguments.
+
+    No interface is provided to add/remove/replace nodes that are in a fixed
+    list of arguments. Indeed, these nodes are the spine of the tree and a
+    mismanipulation would make the tree inconsistent.
+
+    It is however possible to modify the content of fixed argument nodes via
+    @ref NodeInterfaceApis APIs.
+  @}
+*/
+
+/** Remove the Node from its parent's variable list of arguments.
+
+  The function will fail if the Node is in its parent's fixed
+  argument list.
+  The Node is not deleted. The deletion is done separately
+  from the removal.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  Node  Pointer to a Node.
+                      Must be a data node or an object node.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlRemoveNodeFromVarArgList (
+  IN  AML_NODE_HANDLE   Node
+  );
+
+/** Add the NewNode to the head of the variable list of arguments
+    of the ParentNode.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  ParentNode  Pointer to the parent node.
+                            Must be a root or an object node.
+  @param  [in]  NewNode     Pointer to the node to add.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlVarListAddHead (
+  IN  AML_NODE_HANDLE   ParentNode,
+  IN  AML_NODE_HANDLE   NewNode
+  );
+
+/** Add the NewNode to the tail of the variable list of arguments
+    of the ParentNode.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  ParentNode  Pointer to the parent node.
+                            Must be a root or an object node.
+  @param  [in]  NewNode     Pointer to the node to add.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlVarListAddTail (
+  IN  AML_NODE_HANDLE   ParentNode,
+  IN  AML_NODE_HANDLE   NewNode
+  );
+
+/** Add the NewNode before the Node in the list of variable
+    arguments of the Node's parent.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  Node      Pointer to a node.
+                          Must be a root or an object node.
+  @param  [in]  NewNode   Pointer to the node to add.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlVarListAddBefore (
+  IN  AML_NODE_HANDLE   Node,
+  IN  AML_NODE_HANDLE   NewNode
+  );
+
+/** Add the NewNode after the Node in the variable list of arguments
+    of the Node's parent.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  Node      Pointer to a node.
+                          Must be a root or an object node.
+  @param  [in]  NewNode   Pointer to the node to add.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlVarListAddAfter (
+  IN  AML_NODE_HANDLE   Node,
+  IN  AML_NODE_HANDLE   NewNode
+  );
+
+/** Append a Resource Data node to the BufferOpNode.
+
+  The Resource Data node is added at the end of the variable
+  list of arguments of the BufferOpNode, but before the End Tag.
+  If no End Tag is found, the function returns an error.
+
+  @param  [in]  BufferOpNode  Buffer node containing resource data elements.
+  @param  [in]  NewRdNode     The new Resource Data node to add.
+
+  @retval  EFI_SUCCESS            The function completed successfully.
+  @retval  EFI_INVALID_PARAMETER  Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlAppendRdNode (
+  IN  AML_OBJECT_NODE_HANDLE   BufferOpNode,
+  IN  AML_DATA_NODE_HANDLE     NewRdNode
+  );
+
+/** Replace the OldNode, which is in a variable list of arguments,
+    with the NewNode.
+
+  Note: This function unlinks the OldNode from the tree. It is the callers
+        responsibility to delete the OldNode if needed.
+
+  @ingroup TreeModificationApis
+
+  @param  [in]  OldNode   Pointer to the node to replace.
+                          Must be a data node or an object node.
+  @param  [in]  NewNode   The new node to insert.
+                          Must be a data node or an object node.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlReplaceVariableArgument (
+  IN  AML_NODE_HANDLE   OldNode,
+  IN  AML_NODE_HANDLE   NewNode
+  );
+
+/**
+  @defgroup NodeInterfaceApis Node Interface APIs
+  @ingroup AMLLib
+  @{
+    Node Interface APIs allow to query information from a node. Some functions
+    expect a specific node type among the root/object/data node types.
+
+    For instance, AmlGetRootNodeInfo expects to receive a root node.
+
+    E.g.: Query the node type, the ACPI header stored in the root node,
+          the OpCode/SubOpCode/PkgLen of an object node, the type of data
+          stored in a data node, etc.
+
+    These APIs also allow to update some information.
+
+    E.g.: The ACPI header stored in the root node, the buffer of a data node.
+
+    The information of object nodes and the data type of data nodes cannot be
+    modified. This prevents the creation of an inconsistent tree.
+
+    It is however possible to remove a node from a variable list of arguments
+    and replace it. Use the @ref TreeModificationApis APIs for this.
+  @}
+*/
+
+/** Returns the tree node type (Root/Object/Data).
+
+  @ingroup NodeInterfaceApis
+
+  @param [in] Node  Pointer to a Node.
+
+  @return The node type.
+           EAmlNodeUnknown if invalid parameter.
+**/
+EAML_NODE_TYPE
+EFIAPI
+AmlGetNodeType (
+  IN  AML_NODE_HANDLE   Node
+  );
+
+/** Get the RootNode information.
+    The Node must be a root node.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE            RootNode,
+  OUT EFI_ACPI_DESCRIPTION_HEADER   * SdtHeaderBuffer
+  );
+
+/** Get the ObjectNode information.
+    The Node must be an object node.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE    ObjectNode,
+  OUT UINT8                   * OpCode,           OPTIONAL
+  OUT UINT8                   * SubOpCode,        OPTIONAL
+  OUT UINT32                  * PkgLen,           OPTIONAL
+  OUT BOOLEAN                 * IsNameSpaceNode   OPTIONAL
+  );
+
+/** Returns the count of the fixed arguments for the input Node.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE  Node
+  );
+
+/** Get the data type of the DataNode.
+    The Node must be a data node.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE    DataNode,
+  OUT EAML_NODE_DATA_TYPE   * DataType
+  );
+
+/** 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.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE    DataNode,
+  OUT AML_RD_HEADER         * ResourceDataType
+  );
+
+/** 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.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE    DataNode,
+      OUT UINT8                 * Buffer,     OPTIONAL
+  IN  OUT UINT32                * BufferSize
+  );
+
+/** 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.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE            RootNode,
+  IN  CONST EFI_ACPI_DESCRIPTION_HEADER   * SdtHeader
+  );
+
+/** 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_HANDLE    IntegerOpNode,
+  IN  UINT64                    NewInteger
+  );
+
+/** 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.
+
+  @ingroup NodeInterfaceApis
+
+  @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_HANDLE    DataNode,
+  IN  EAML_NODE_DATA_TYPE     DataType,
+  IN  UINT8                 * Buffer,
+  IN  UINT32                  Size
+  );
+
+/**
+  @defgroup NavigationApis Navigation APIs
+  @ingroup AMLLib
+  @{
+    Navigation APIs allow to navigate in the AML tree. There are different
+    ways to navigate in the tree by:
+     - Direct relation (@ref CoreNavigationApis);
+     - Enumeration: enumerate all the nodes and call a callback function
+       (@ref EnumerationApis);
+     - Iteration: instantiate an iterator and use it to navigate
+       (@ref IteratorApis);
+     - NameSpace path: use the AML namespace to navigate the tree
+       (@ref NameSpaceApis).
+  @}
+*/
+
+/**
+  @defgroup CoreNavigationApis Core Navigation APIs
+  @ingroup NavigationApis
+  @{
+    Core Navigation APIs allow to get a node by specifying a relation.
+
+    E.g.: Get the parent, the n-th fixed argument, the next variable
+          argument, etc.
+  @}
+*/
+
+/** Get the parent node of the input Node.
+
+  @ingroup CoreNavigationApis
+
+  @param [in] Node  Pointer to a node.
+
+  @return The parent node of the input Node.
+          NULL otherwise.
+**/
+AML_NODE_HANDLE
+EFIAPI
+AmlGetParent (
+  IN  AML_NODE_HANDLE   Node
+  );
+
+/** Get the node at the input Index in the fixed argument list of the input
+    ObjectNode.
+
+  @ingroup CoreNavigationApis
+
+  @param  [in]  ObjectNode  Pointer to an object node.
+  @param  [in]  Index       The Index of the fixed argument to get.
+
+  @return The node at the input Index in the fixed argument list
+          of the input ObjectNode.
+          NULL otherwise, e.g. if the node is not an object node, or no
+          node is available at this Index.
+**/
+AML_NODE_HANDLE
+EFIAPI
+AmlGetFixedArgument (
+  IN  AML_OBJECT_NODE_HANDLE  ObjectNode,
+  IN  EAML_PARSE_INDEX        Index
+  );
+
+/** Get the sibling node among the nodes being in
+    the same variable argument list.
+
+  (ParentNode)  /-i                 # Child of fixed argument b
+      \        /
+       |- [a][b][c][d]              # Fixed Arguments
+       |- {(VarArgNode)->(f)->(g)}  # Variable Arguments
+             \
+              \-h                   # Child of variable argument e
+
+  Node must be in a variable list of arguments.
+  Traversal Order: VarArgNode, f, g, NULL
+
+  @ingroup CoreNavigationApis
+
+  @param  [in]  VarArgNode  Pointer to a node.
+                            Must be in a variable list of arguments.
+
+  @return The next node after VarArgNode in the variable list of arguments.
+          Return NULL if
+          - VarArgNode is the last node of the list, or
+          - VarArgNode is not part of a variable list of arguments.
+**/
+AML_NODE_HANDLE
+EFIAPI
+AmlGetSiblingVariableArgument (
+  IN  AML_NODE_HANDLE   VarArgNode
+  );
+
+/** Get the next variable argument.
+
+  (Node)        /-i           # Child of fixed argument b
+      \        /
+       |- [a][b][c][d]        # Fixed Arguments
+       |- {(e)->(f)->(g)}     # Variable Arguments
+             \
+              \-h             # Child of variable argument e
+
+  Traversal Order: e, f, g, NULL
+
+  @ingroup CoreNavigationApis
+
+  @param  [in]  Node        Pointer to a Root node or Object Node.
+  @param  [in]  CurrVarArg  Pointer to the Current Variable Argument.
+
+  @return The node after the CurrVarArg in the variable list of arguments.
+          If CurrVarArg is NULL, return the first node of the
+          variable argument list.
+          Return NULL if
+          - CurrVarArg is the last node of the list, or
+          - Node does not have a variable list of arguments.
+**/
+AML_NODE_HANDLE
+EFIAPI
+AmlGetNextVariableArgument (
+  IN  AML_NODE_HANDLE   Node,
+  IN  AML_NODE_HANDLE   CurrVarArg
+  );
+
+/** Get the previous variable argument.
+
+  (Node)        /-i           # Child of fixed argument b
+      \        /
+       |- [a][b][c][d]        # Fixed Arguments
+       |- {(e)->(f)->(g)}     # Variable Arguments
+             \
+              \-h             # Child of variable argument e
+
+  Traversal Order: g, f, e, NULL
+
+  @ingroup CoreNavigationApis
+
+  @param  [in]  Node        Pointer to a root node or an object node.
+  @param  [in]  CurrVarArg  Pointer to the Current Variable Argument.
+
+  @return The node before the CurrVarArg in the variable list of
+          arguments.
+          If CurrVarArg is NULL, return the last node of the
+          variable list of arguments.
+          Return NULL if:
+          - CurrVarArg is the first node of the list, or
+          - Node doesn't have a variable list of arguments.
+**/
+AML_NODE_HANDLE
+EFIAPI
+AmlGetPreviousVariableArgument (
+  IN  AML_NODE_HANDLE   Node,
+  IN  AML_NODE_HANDLE   CurrVarArg
+  );
+
+/**
+  @defgroup EnumerationApis Enumeration APIs
+  @ingroup NavigationApis
+  @{
+    Enumeration APIs are navigation APIs, allowing to call a callback function
+    on each node enumerated. Nodes are enumerated in the AML bytestream order,
+    i.e. in a depth first order.
+  @}
+*/
+
+/**
+  Callback function prototype used when iterating through the tree.
+
+  @ingroup EnumerationApis
+
+  @param  [in]      Node      The Node currently being processed.
+  @param  [in, out] Context   A context for the callback function.
+                                Can be optional.
+  @param  [in, out] Status    End the enumeration if pointing to a value
+                                evaluated to TRUE.
+                                Can be optional.
+
+  @retval TRUE if the enumeration can continue or has finished without
+          interruption.
+  @retval FALSE if the enumeration needs to stopped or has stopped.
+**/
+typedef
+BOOLEAN
+(EFIAPI * EDKII_AML_TREE_ENUM_CALLBACK) (
+  IN       AML_NODE_HANDLE     Node,
+  IN  OUT  VOID              * Context,    OPTIONAL
+  IN  OUT  EFI_STATUS        * Status      OPTIONAL
+  );
+
+/** Enumerate all nodes of the subtree under the input Node in the AML
+    bytestream order (i.e. in a depth first order), and call the CallBack
+    function with the input Context.
+    The prototype of the Callback function is EDKII_AML_TREE_ENUM_CALLBACK.
+
+  @ingroup EnumerationApis
+
+  @param  [in]      Node      Enumerate nodes of the subtree under this Node.
+                              Must be a valid node.
+  @param  [in]      CallBack  Callback function to call on each node.
+  @param  [in, out] Context   Void pointer used to pass some information
+                              to the Callback function.
+                              Optional, can be NULL.
+  @param  [out]     Status    Optional parameter that can be used to get
+                              the status of the Callback function.
+                              If used, need to be init to EFI_SUCCESS.
+
+  @retval TRUE if the enumeration can continue or has finished without
+          interruption.
+  @retval FALSE if the enumeration needs to stopped or has stopped.
+**/
+BOOLEAN
+EFIAPI
+AmlEnumTree (
+  IN      AML_NODE_HANDLE                 Node,
+  IN      EDKII_AML_TREE_ENUM_CALLBACK    CallBack,
+  IN  OUT VOID                          * Context,  OPTIONAL
+      OUT EFI_STATUS                    * Status    OPTIONAL
+  );
+
+/**
+  @defgroup NameSpaceApis NameSpace APIs
+  @ingroup NavigationApis
+  @{
+    NameSpace APIs allow to find a node from an AML path, and reciprocally
+    get the AML path of a node.
+
+    These APIs only operate on "NameSpace nodes", i.e. nodes that are
+    part of the AML namespace. These are the root node and object nodes
+    acknowledged by AmlGetObjectNodeInfo in @ref NodeInterfaceApis.
+  @}
+*/
+
+/** Build the absolute ASL pathname to Node.
+
+  BufferSize is always updated to the size of the pathname.
+
+  If:
+   - the content of BufferSize is >= to the size of the pathname AND;
+   - Buffer is not NULL;
+  then copy the pathname in the Buffer. A buffer of the size
+  MAX_ASL_NAMESTRING_SIZE is big enough to receive any ASL pathname.
+
+  @ingroup NameSpaceApis
+
+  @param  [in]      Node            Node to build the absolute path to.
+                                    Must be a root node, or a namespace node.
+  @param  [out]     Buffer          Buffer to write the path to.
+                                    If NULL, only update *BufferSize.
+  @param  [in, out] BufferSize      Pointer holding:
+                                     - At entry, the size of the Buffer;
+                                     - At exit, the size of the pathname.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_BUFFER_TOO_SMALL    No space left in the buffer.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_OUT_OF_RESOURCES    Out of memory.
+**/
+EFI_STATUS
+EFIAPI
+AmlGetAslPathName (
+  IN      AML_NODE_HANDLE     Node,
+      OUT CHAR8             * Buffer,
+  IN  OUT UINT32            * BufferSize
+  );
+
+#endif // AML_CORE_INTERFACE_H_
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'