[mirror_edk2.git] / IntelFrameworkModulePkg / Universal / SectionExtractionDxe / SectionExtraction.c

/**@file\r
  Section Extraction Protocol implementation.\r
  \r
  Stream database is implemented as a linked list of section streams,\r
  where each stream contains a linked list of children, which may be leaves or\r
  encapsulations.  \r
  \r
  Children that are encapsulations generate new stream entries\r
  when they are created.  Streams can also be created by calls to \r
  SEP->OpenSectionStream().\r
  \r
  The database is only created far enough to return the requested data from\r
  any given stream, or to determine that the requested data is not found.\r
  \r
  If a GUIDed encapsulation is encountered, there are three possiblilites.\r
  \r
  1) A support protocol is found, in which the stream is simply processed with\r
     the support protocol.\r
     \r
  2) A support protocol is not found, but the data is available to be read\r
     without processing.  In this case, the database is built up through the\r
     recursions to return the data, and a RPN event is set that will enable\r
     the stream in question to be refreshed if and when the required section\r
     extraction protocol is published.This insures the AuthenticationStatus \r
     does not become stale in the cache.\r
     \r
  3) A support protocol is not found, and the data is not available to be read\r
     without it.  This results in EFI_PROTOCOL_ERROR.\r
\r
Copyright (c) 2006, Intel Corporation                                                         \r
All rights reserved. This program and the accompanying materials                          \r
are licensed and made available under the terms and conditions of the BSD License         \r
which accompanies this distribution.  The full text of the license may be found at        \r
http://opensource.org/licenses/bsd-license.php                                            \r
                                                                                          \r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
\r
\r
**/\r
\r
#include "SectionExtraction.h"\r
\r
//\r
// Local defines and typedefs\r
//\r
#define CORE_SECTION_CHILD_SIGNATURE  EFI_SIGNATURE_32('S','X','C','S')\r
#define CHILD_SECTION_NODE_FROM_LINK(Node) \\r
  CR (Node, CORE_SECTION_CHILD_NODE, Link, CORE_SECTION_CHILD_SIGNATURE)\r
\r
typedef struct {\r
  UINT32                      Signature;\r
  LIST_ENTRY                  Link;\r
  UINT32                      Type;\r
  UINT32                      Size;\r
  //\r
  // StreamBase + OffsetInStream == pointer to section header in stream.  The\r
  // stream base is always known when walking the sections within.\r
  //\r
  UINT32                      OffsetInStream;\r
  //\r
  // Then EncapsulatedStreamHandle below is always 0 if the section is NOT an\r
  // encapsulating section.  Otherwise, it contains the stream handle\r
  // of the encapsulated stream.  This handle is ALWAYS produced any time an\r
  // encapsulating child is encountered, irrespective of whether the\r
  // encapsulated stream is processed further.\r
  //\r
  UINTN                       EncapsulatedStreamHandle;\r
  EFI_GUID                    *EncapsulationGuid;\r
} CORE_SECTION_CHILD_NODE;\r
\r
#define CORE_SECTION_STREAM_SIGNATURE EFI_SIGNATURE_32('S','X','S','S')\r
#define STREAM_NODE_FROM_LINK(Node) \\r
  CR (Node, CORE_SECTION_STREAM_NODE, Link, CORE_SECTION_STREAM_SIGNATURE)\r
\r
typedef struct {\r
  UINT32                      Signature;\r
  LIST_ENTRY                  Link;\r
  UINTN                       StreamHandle;\r
  UINT8                       *StreamBuffer;\r
  UINTN                       StreamLength;\r
  LIST_ENTRY                  Children;\r
  //\r
  // Authentication status is from GUIDed encapsulations.\r
  //\r
  UINT32                      AuthenticationStatus;\r
} CORE_SECTION_STREAM_NODE;\r
\r
#define NULL_STREAM_HANDLE    0\r
\r
typedef struct {\r
  CORE_SECTION_CHILD_NODE     *ChildNode;\r
  CORE_SECTION_STREAM_NODE    *ParentStream;\r
  VOID                        *Registration;\r
  EFI_EVENT                   Event;\r
} RPN_EVENT_CONTEXT;\r
  \r
  \r
EFI_EVENT\r
CoreCreateProtocolNotifyEvent (\r
  IN EFI_GUID             *ProtocolGuid,\r
  IN EFI_TPL              NotifyTpl,\r
  IN EFI_EVENT_NOTIFY     NotifyFunction,\r
  IN VOID                 *NotifyContext,\r
  OUT VOID                **Registration,\r
  IN  BOOLEAN             SignalFlag\r
  );\r
\r
//\r
// Local prototypes\r
//\r
\r
STATIC\r
BOOLEAN\r
ChildIsType (\r
  IN CORE_SECTION_STREAM_NODE                 *Stream,\r
  IN CORE_SECTION_CHILD_NODE                  *Child,\r
  IN EFI_SECTION_TYPE                         SearchType,\r
  IN EFI_GUID                                 *SectionDefinitionGuid\r
  );\r
\r
STATIC\r
VOID\r
EFIAPI\r
NotifyGuidedExtraction (\r
  IN  EFI_EVENT                             Event,\r
  IN  VOID                                  *RpnContext\r
  );\r
\r
STATIC\r
VOID\r
CreateGuidedExtractionRpnEvent (\r
  IN CORE_SECTION_STREAM_NODE                 *ParentStream,\r
  IN CORE_SECTION_CHILD_NODE                  *ChildNode\r
  );\r
\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
OpenSectionStream (\r
  IN     EFI_SECTION_EXTRACTION_PROTOCOL      *This,\r
  IN     UINTN                                SectionStreamLength,\r
  IN     VOID                                 *SectionStream,\r
     OUT UINTN                                *SectionStreamHandle\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
EFIAPI\r
GetSection (\r
  IN EFI_SECTION_EXTRACTION_PROTOCOL          *This,\r
  IN UINTN                                    SectionStreamHandle,\r
  IN EFI_SECTION_TYPE                         *SectionType,\r
  IN EFI_GUID                                 *SectionDefinitionGuid,\r
  IN UINTN                                    SectionInstance,\r
  IN VOID                                     **Buffer,\r
  IN OUT UINTN                                *BufferSize,\r
  OUT UINT32                                  *AuthenticationStatus\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
EFIAPI\r
CloseSectionStream (\r
  IN  EFI_SECTION_EXTRACTION_PROTOCOL         *This,\r
  IN  UINTN                                   StreamHandleToClose\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
FindStreamNode (\r
  IN  UINTN                                   SearchHandle,\r
  OUT CORE_SECTION_STREAM_NODE                **FoundStream\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
FindChildNode (\r
  IN     CORE_SECTION_STREAM_NODE             *SourceStream,\r
  IN     EFI_SECTION_TYPE                     SearchType,\r
  IN     UINTN                                *SectionInstance,\r
  IN     EFI_GUID                             *SectionDefinitionGuid,\r
  OUT    CORE_SECTION_CHILD_NODE              **FoundChild,\r
  OUT    CORE_SECTION_STREAM_NODE             **FoundStream,\r
  OUT    UINT32                               *AuthenticationStatus\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
CreateChildNode (\r
  IN     CORE_SECTION_STREAM_NODE             *Stream,\r
  IN     UINT32                               ChildOffset,\r
  OUT    CORE_SECTION_CHILD_NODE              **ChildNode\r
  );\r
  \r
STATIC\r
VOID\r
FreeChildNode (\r
  IN  CORE_SECTION_CHILD_NODE                 *ChildNode\r
  );\r
  \r
STATIC\r
EFI_STATUS\r
OpenSectionStreamEx (\r
  IN     UINTN                                SectionStreamLength,\r
  IN     VOID                                 *SectionStream,\r
  IN     BOOLEAN                              AllocateBuffer,\r
  IN     UINT32                               AuthenticationStatus,   \r
     OUT UINTN                                *SectionStreamHandle\r
  );\r
  \r
STATIC\r
BOOLEAN\r
IsValidSectionStream (\r
  IN  VOID                                    *SectionStream,\r
  IN  UINTN                                   SectionStreamLength\r
  );\r
\r
//\r
// Module globals\r
//\r
LIST_ENTRY mStreamRoot = INITIALIZE_LIST_HEAD_VARIABLE (mStreamRoot);\r
\r
EFI_HANDLE mSectionExtractionHandle = NULL;\r
\r
EFI_SECTION_EXTRACTION_PROTOCOL mSectionExtraction = { \r
  OpenSectionStream, \r
  GetSection, \r
  CloseSectionStream\r
};\r
\r
/**\r
  Entry point of the section extraction code. Initializes an instance of the \r
  section extraction interface and installs it on a new handle.\r
\r
  @param ImageHandle   EFI_HANDLE: A handle for the image that is initializing this driver\r
  @param SystemTable   EFI_SYSTEM_TABLE: A pointer to the EFI system table        \r
\r
  @retval EFI_SUCCESS            Driver initialized successfully\r
  @retval EFI_OUT_OF_RESOURCES   Could not allocate needed resources\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
SectionExtractionEntryPoint (\r
  IN EFI_HANDLE                   ImageHandle,\r
  IN EFI_SYSTEM_TABLE             *SystemTable\r
  )\r
{\r
  EFI_STATUS                         Status;\r
\r
  //\r
  // Install SEP to a new handle\r
  //\r
  Status = gBS->InstallProtocolInterface (\r
                  &mSectionExtractionHandle,\r
                  &gEfiSectionExtractionProtocolGuid,\r
                  EFI_NATIVE_INTERFACE,\r
                  &mSectionExtraction\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r
\r
/**\r
  SEP member function.  This function creates and returns a new section stream\r
  handle to represent the new section stream.\r
\r
  @param This                 Indicates the calling context.\r
  @param SectionStreamLength  Size in bytes of the section stream.\r
  @param SectionStream        Buffer containing the new section stream.\r
  @param SectionStreamHandle  A pointer to a caller allocated UINTN that on output\r
                              contains the new section stream handle.\r
\r
  @retval EFI_SUCCESS\r
  @retval EFI_OUT_OF_RESOURCES  memory allocation failed.\r
  @retval EFI_INVALID_PARAMETER section stream does not end concident with end of\r
                                last section.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
OpenSectionStream (\r
  IN     EFI_SECTION_EXTRACTION_PROTOCOL           *This,\r
  IN     UINTN                                     SectionStreamLength,\r
  IN     VOID                                      *SectionStream,\r
     OUT UINTN                                     *SectionStreamHandle\r
  )\r
{\r
  //\r
  // Check to see section stream looks good...\r
  //\r
  if (!IsValidSectionStream (SectionStream, SectionStreamLength)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
  \r
  return OpenSectionStreamEx ( \r
          SectionStreamLength, \r
          SectionStream,\r
          TRUE,\r
          0,\r
          SectionStreamHandle\r
          );\r
}\r
  \r
/**\r
  SEP member function.  Retrieves requested section from section stream.\r
\r
  @param This:                 Pointer to SEP instance.\r
  @param SectionStreamHandle:  The section stream from which to extract the requested\r
                               section.\r
  @param SectionType:         A pointer to the type of section to search for.\r
  @param SectionDefinitionGuid: If the section type is EFI_SECTION_GUID_DEFINED, then\r
                                SectionDefinitionGuid indicates which of these types\r
                                of sections to search for.\r
  @param SectionInstance:      Indicates which instance of the requested section to\r
                               return.\r
  @param Buffer:               Double indirection to buffer.  If *Buffer is non-null on\r
                               input, then the buffer is caller allocated.  If\r
                               *Buffer is NULL, then the buffer is callee allocated.\r
                               In either case, the requried buffer size is returned\r
                               in *BufferSize.\r
  @param BufferSize:           On input, indicates the size of *Buffer if *Buffer is\r
                               non-null on input.  On output, indicates the required\r
                               size (allocated size if callee allocated) of *Buffer.\r
  @param AuthenticationStatus: Indicates the authentication status of the retrieved\r
                               section.\r
\r
 \r
  @retval EFI_SUCCESS:        Section was retrieved successfully\r
  @retval EFI_PROTOCOL_ERROR: A GUID defined section was encountered in the section \r
                        stream with its EFI_GUIDED_SECTION_PROCESSING_REQUIRED\r
                        bit set, but there was no corresponding GUIDed Section \r
                        Extraction Protocol in the handle database.  *Buffer is \r
                        unmodified.\r
  @retval EFI_NOT_FOUND:      An error was encountered when parsing the SectionStream.\r
                        This indicates the SectionStream  is not correctly \r
                        formatted.\r
  @retval EFI_NOT_FOUND:      The requested section does not exist.\r
  @retval EFI_OUT_OF_RESOURCES: The system has insufficient resources to process the \r
                        request.\r
  @retval EFI_INVALID_PARAMETER: The SectionStreamHandle does not exist.\r
  @retval EFI_WARN_TOO_SMALL: The size of the caller allocated input buffer is \r
                        insufficient to contain the requested section.  The \r
                        input buffer is filled and contents are section contents\r
                        are truncated.\r
\r
**/  \r
STATIC\r
EFI_STATUS\r
EFIAPI\r
GetSection (\r
  IN EFI_SECTION_EXTRACTION_PROTOCOL                    *This,\r
  IN UINTN                                              SectionStreamHandle,\r
  IN EFI_SECTION_TYPE                                   *SectionType,\r
  IN EFI_GUID                                           *SectionDefinitionGuid,\r
  IN UINTN                                              SectionInstance,\r
  IN VOID                                               **Buffer,\r
  IN OUT UINTN                                          *BufferSize,\r
  OUT UINT32                                            *AuthenticationStatus\r
  )\r
\r
{\r
  CORE_SECTION_STREAM_NODE                              *StreamNode;\r
  EFI_TPL                                               OldTpl;\r
  EFI_STATUS                                            Status;\r
  CORE_SECTION_CHILD_NODE                               *ChildNode;\r
  CORE_SECTION_STREAM_NODE                              *ChildStreamNode;\r
  UINTN                                                 CopySize;\r
  UINT32                                                ExtractedAuthenticationStatus;\r
  UINTN                                                 Instance;\r
  UINT8                                                 *CopyBuffer;\r
  UINTN                                                 SectionSize;\r
  \r
\r
  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);\r
  Instance = SectionInstance + 1;\r
  \r
  //\r
  // Locate target stream\r
  //\r
  Status = FindStreamNode (SectionStreamHandle, &StreamNode);\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_INVALID_PARAMETER;\r
    goto GetSection_Done;\r
  }\r
  \r
  //\r
  // Found the stream, now locate and return the appropriate section\r
  //\r
  if (SectionType == NULL) {\r
    //\r
    // SectionType == NULL means return the WHOLE section stream...\r
    //\r
    CopySize = StreamNode->StreamLength;\r
    CopyBuffer = StreamNode->StreamBuffer;\r
    *AuthenticationStatus = StreamNode->AuthenticationStatus;\r
  } else {\r
    //\r
    // There's a requested section type, so go find it and return it...\r
    //\r
    Status = FindChildNode (\r
                      StreamNode, \r
                      *SectionType, \r
                      &Instance, \r
                      SectionDefinitionGuid,\r
                      &ChildNode,\r
                      &ChildStreamNode, \r
                      &ExtractedAuthenticationStatus\r
                      );\r
    if (EFI_ERROR (Status)) {\r
      goto GetSection_Done;\r
    }\r
    CopySize = ChildNode->Size - sizeof (EFI_COMMON_SECTION_HEADER);\r
    CopyBuffer = ChildStreamNode->StreamBuffer + ChildNode->OffsetInStream + sizeof (EFI_COMMON_SECTION_HEADER);\r
    *AuthenticationStatus = ExtractedAuthenticationStatus;\r
  }   \r
    \r
  SectionSize = CopySize;  \r
  if (*Buffer != NULL) {\r
    //\r
    // Caller allocated buffer.  Fill to size and return required size...\r
    //\r
    if (*BufferSize < CopySize) {\r
      Status = EFI_WARN_BUFFER_TOO_SMALL;\r
      CopySize = *BufferSize;\r
    }\r
  } else {\r
    //\r
    // Callee allocated buffer.  Allocate buffer and return size.\r
    //\r
    *Buffer = AllocatePool (CopySize);\r
    if (*Buffer == NULL) {\r
      Status = EFI_OUT_OF_RESOURCES;\r
      goto GetSection_Done;\r
    }\r
  }\r
  CopyMem (*Buffer, CopyBuffer, CopySize);\r
  *BufferSize = SectionSize;\r
  \r
GetSection_Done:\r
  gBS->RestoreTPL (OldTpl);\r
  return Status;\r
}\r
\r
/**\r
  SEP member function.  Deletes an existing section stream\r
\r
  @param This                - Indicates the calling context.\r
  @param StreamHandleToClose - Indicates the stream to close\r
\r
  @retval EFI_SUCCESS\r
  @retval EFI_OUT_OF_RESOURCES - memory allocation failed.\r
  @retval EFI_INVALID_PARAMETER - section stream does not end concident with end of\r
                          last section.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
CloseSectionStream (\r
  IN  EFI_SECTION_EXTRACTION_PROTOCOL           *This,\r
  IN  UINTN                                     StreamHandleToClose\r
  )\r
\r
{\r
  CORE_SECTION_STREAM_NODE                      *StreamNode;\r
  EFI_TPL                                       OldTpl;\r
  EFI_STATUS                                    Status;\r
  LIST_ENTRY                                    *Link;\r
  CORE_SECTION_CHILD_NODE                       *ChildNode;\r
  \r
  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);\r
  \r
  //\r
  // Locate target stream\r
  //\r
  Status = FindStreamNode (StreamHandleToClose, &StreamNode);\r
  if (!EFI_ERROR (Status)) {\r
    //\r
    // Found the stream, so close it\r
    //\r
    RemoveEntryList (&StreamNode->Link);\r
    while (!IsListEmpty (&StreamNode->Children)) {\r
      Link = GetFirstNode (&StreamNode->Children);\r
      ChildNode = CHILD_SECTION_NODE_FROM_LINK (Link);\r
      FreeChildNode (ChildNode);\r
    }\r
    gBS->FreePool (StreamNode->StreamBuffer);\r
    gBS->FreePool (StreamNode);\r
    Status = EFI_SUCCESS;\r
  } else {\r
    Status = EFI_INVALID_PARAMETER;\r
  }\r
  \r
  gBS->RestoreTPL (OldTpl);\r
  return Status;\r
}\r
\r
/**\r
  Worker function.  Determine if the input stream:child matches the input type.\r
\r
  @param Stream              - Indicates the section stream associated with the child\r
  @param Child               - Indicates the child to check\r
  @param SearchType          - Indicates the type of section to check against for\r
  @param SectionDefinitionGuid - Indicates the GUID to check against if the type is\r
                        EFI_SECTION_GUID_DEFINED\r
\r
  @retval TRUE                - The child matches\r
  @retval FALSE               - The child doesn't match\r
\r
**/\r
STATIC\r
BOOLEAN\r
ChildIsType (\r
  IN CORE_SECTION_STREAM_NODE *Stream,\r
  IN CORE_SECTION_CHILD_NODE  *Child,\r
  IN EFI_SECTION_TYPE         SearchType,\r
  IN EFI_GUID                 *SectionDefinitionGuid\r
  )\r
{\r
  EFI_GUID_DEFINED_SECTION    *GuidedSection;\r
  \r
  if (SearchType == EFI_SECTION_ALL) {\r
    return TRUE;\r
  }\r
  if (Child->Type != SearchType) {\r
    return FALSE;\r
  }\r
  if (SearchType != EFI_SECTION_GUID_DEFINED) {\r
    return TRUE;\r
  }\r
  GuidedSection = (EFI_GUID_DEFINED_SECTION * )(Stream->StreamBuffer + Child->OffsetInStream);\r
  return CompareGuid (&GuidedSection->SectionDefinitionGuid, SectionDefinitionGuid);\r
}\r
\r
/**\r
  Worker function  Recursively searches / builds section stream database\r
  looking for requested section.\r
\r
\r
  @param SourceStream        - Indicates the section stream in which to do the search.\r
  @param SearchType          - Indicates the type of section to search for.\r
  @param SectionInstance     - Indicates which instance of section to find.  This is\r
                        an in/out parameter to deal with recursions.\r
  @param SectionDefinitionGuid  - Guid of section definition\r
  @param FoundChild          - Output indicating the child node that is found.\r
  @param FoundStream         - Output indicating which section stream the child was\r
                        found in.  If this stream was generated as a result of\r
                        an encapsulation section, the streamhandle is visible\r
                        within the SEP driver only.\r
  @param AuthenticationStatus- Indicates the authentication status of the found section.\r
\r
  @retval EFI_SUCCESS         - Child node was found and returned.\r
  @retval EFI_OUT_OF_RESOURCES- Memory allocation failed.\r
  @retval EFI_NOT_FOUND       - Requested child node does not exist.\r
  @retval EFI_PROTOCOL_ERROR  - a required GUIDED section extraction protocol does not\r
                        exist\r
\r
**/\r
STATIC\r
EFI_STATUS\r
FindChildNode (\r
  IN     CORE_SECTION_STREAM_NODE                   *SourceStream,\r
  IN     EFI_SECTION_TYPE                           SearchType,\r
  IN OUT UINTN                                      *SectionInstance,\r
  IN     EFI_GUID                                   *SectionDefinitionGuid,\r
  OUT    CORE_SECTION_CHILD_NODE                    **FoundChild,\r
  OUT    CORE_SECTION_STREAM_NODE                   **FoundStream,\r
  OUT    UINT32                                     *AuthenticationStatus\r
  )\r
\r
{\r
  CORE_SECTION_CHILD_NODE                       *CurrentChildNode;\r
  CORE_SECTION_CHILD_NODE                       *RecursedChildNode;\r
  CORE_SECTION_STREAM_NODE                      *RecursedFoundStream;\r
  UINT32                                        NextChildOffset;\r
  EFI_STATUS                                    ErrorStatus;\r
  EFI_STATUS                                    Status;\r
  \r
  CurrentChildNode = NULL;\r
  ErrorStatus = EFI_NOT_FOUND;\r
  \r
  if (SourceStream->StreamLength == 0) {\r
    return EFI_NOT_FOUND;\r
  }\r
  \r
  if (IsListEmpty (&SourceStream->Children) && \r
                   SourceStream->StreamLength > sizeof (EFI_COMMON_SECTION_HEADER)) {\r
    //\r
    // This occurs when a section stream exists, but no child sections\r
    // have been parsed out yet.  Therefore, extract the first child and add it\r
    // to the list of children so we can get started.\r
    //\r
    Status = CreateChildNode (SourceStream, 0, &CurrentChildNode);\r
    if (EFI_ERROR (Status)) {\r
      return Status;\r
    }\r
  }\r
  \r
  //\r
  // At least one child has been parsed out of the section stream.  So, walk\r
  // through the sections that have already been parsed out looking for the\r
  // requested section, if necessary, continue parsing section stream and\r
  // adding children until either the requested section is found, or we run\r
  // out of data\r
  //\r
  CurrentChildNode = CHILD_SECTION_NODE_FROM_LINK (GetFirstNode(&SourceStream->Children));\r
\r
  for (;;) {\r
    if (ChildIsType (SourceStream, CurrentChildNode, SearchType, SectionDefinitionGuid)) {\r
      //\r
      // The type matches, so check the instance count to see if it's the one we want\r
      //\r
      (*SectionInstance)--;\r
      if (*SectionInstance == 0) {\r
        //\r
        // Got it!\r
        //\r
        *FoundChild = CurrentChildNode;\r
        *FoundStream = SourceStream;\r
        *AuthenticationStatus = SourceStream->AuthenticationStatus;\r
        return EFI_SUCCESS;\r
      }\r
    }\r
    \r
    if (CurrentChildNode->EncapsulatedStreamHandle != NULL_STREAM_HANDLE) {\r
      //\r
      // If the current node is an encapsulating node, recurse into it...\r
      //\r
      Status = FindChildNode (\r
                (CORE_SECTION_STREAM_NODE *)CurrentChildNode->EncapsulatedStreamHandle,\r
                SearchType,\r
                SectionInstance,\r
                SectionDefinitionGuid,\r
                &RecursedChildNode,\r
                &RecursedFoundStream,\r
                AuthenticationStatus\r
                );\r
      //\r
      // If the status is not EFI_SUCCESS, just save the error code and continue\r
      // to find the request child node in the rest stream.\r
      //\r
      if (*SectionInstance == 0) {\r
        ASSERT_EFI_ERROR (Status);\r
        *FoundChild = RecursedChildNode;\r
        *FoundStream = RecursedFoundStream;\r
        return EFI_SUCCESS;\r
      } else {\r
        ErrorStatus = Status;\r
      }\r
    }\r
    \r
    if (!IsNodeAtEnd (&SourceStream->Children, &CurrentChildNode->Link)) {\r
      //\r
      // We haven't found the child node we're interested in yet, but there's\r
      // still more nodes that have already been parsed so get the next one\r
      // and continue searching..\r
      //\r
      CurrentChildNode = CHILD_SECTION_NODE_FROM_LINK (GetNextNode (&SourceStream->Children, &CurrentChildNode->Link));\r
    } else {\r
      //\r
      // We've exhausted children that have already been parsed, so see if\r
      // there's any more data and continue parsing out more children if there\r
      // is.\r
      //\r
      NextChildOffset = CurrentChildNode->OffsetInStream + CurrentChildNode->Size;\r
      //\r
      // Round up to 4 byte boundary\r
      //\r
      NextChildOffset += 3;\r
      NextChildOffset &= ~(UINTN)3;\r
      if (NextChildOffset <= SourceStream->StreamLength - sizeof (EFI_COMMON_SECTION_HEADER)) {\r
        //\r
        // There's an unparsed child remaining in the stream, so create a new child node\r
        //\r
        Status = CreateChildNode (SourceStream, NextChildOffset, &CurrentChildNode);\r
        if (EFI_ERROR (Status)) {\r
          return Status;\r
        }\r
      } else {\r
        ASSERT (EFI_ERROR (ErrorStatus));\r
        return ErrorStatus;\r
      }\r
    }\r
  }\r
}\r
\r
/**\r
  Worker function.  Constructor for new child nodes.\r
\r
  @param Stream              - Indicates the section stream in which to add the child.\r
  @param ChildOffset         - Indicates the offset in Stream that is the beginning\r
                        of the child section.\r
  @param ChildNode           - Indicates the Callee allocated and initialized child.\r
\r
  @retval EFI_SUCCESS         - Child node was found and returned.\r
  @retval EFI_OUT_OF_RESOURCES- Memory allocation failed.\r
  @retval EFI_PROTOCOL_ERROR  - Encapsulation sections produce new stream handles when\r
                        the child node is created.  If the section type is GUID\r
                        defined, and the extraction GUID does not exist, and\r
                        producing the stream requires the GUID, then a protocol\r
                        error is generated and no child is produced.\r
  Values returned by OpenSectionStreamEx.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
CreateChildNode (\r
  IN     CORE_SECTION_STREAM_NODE              *Stream,\r
  IN     UINT32                                ChildOffset,\r
     OUT CORE_SECTION_CHILD_NODE               **ChildNode\r
  )\r
{\r
  EFI_STATUS                                   Status;\r
  EFI_COMMON_SECTION_HEADER                    *SectionHeader;\r
  EFI_COMPRESSION_SECTION                      *CompressionHeader;\r
  EFI_GUID_DEFINED_SECTION                     *GuidedHeader;\r
  EFI_DECOMPRESS_PROTOCOL                      *Decompress;\r
  EFI_GUIDED_SECTION_EXTRACTION_PROTOCOL       *GuidedExtraction;\r
  VOID                                         *NewStreamBuffer;\r
  VOID                                         *ScratchBuffer;\r
  UINT32                                       ScratchSize;\r
  UINTN                                        NewStreamBufferSize;\r
  UINT32                                       AuthenticationStatus;\r
  UINT32                                       SectionLength;\r
    \r
  CORE_SECTION_CHILD_NODE                      *Node;\r
\r
  SectionHeader = (EFI_COMMON_SECTION_HEADER *) (Stream->StreamBuffer + ChildOffset);\r
\r
  //\r
  // Allocate a new node\r
  //\r
  *ChildNode = AllocatePool (sizeof (CORE_SECTION_CHILD_NODE));\r
  Node = *ChildNode;\r
  if (Node == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
  \r
  //\r
  // Now initialize it\r
  //\r
  Node->Signature = CORE_SECTION_CHILD_SIGNATURE;\r
  Node->Type = SectionHeader->Type;\r
  Node->Size = SECTION_SIZE (SectionHeader);\r
  Node->OffsetInStream = ChildOffset;\r
  Node->EncapsulatedStreamHandle = NULL_STREAM_HANDLE;\r
  Node->EncapsulationGuid = NULL;\r
  \r
  //\r
  // If it's an encapsulating section, then create the new section stream also\r
  //\r
  switch (Node->Type) {\r
    case EFI_SECTION_COMPRESSION:\r
      //\r
      // Get the CompressionSectionHeader\r
      //\r
      ASSERT (Node->Size >= sizeof (EFI_COMPRESSION_SECTION));\r
      \r
      CompressionHeader = (EFI_COMPRESSION_SECTION *) SectionHeader;\r
      \r
      //\r
      // Allocate space for the new stream\r
      //\r
      if (CompressionHeader->UncompressedLength > 0) {\r
        NewStreamBufferSize = CompressionHeader->UncompressedLength;\r
        NewStreamBuffer = AllocatePool (NewStreamBufferSize);\r
        if (NewStreamBuffer == NULL) {\r
          gBS->FreePool (Node);\r
          return EFI_OUT_OF_RESOURCES;\r
        }\r
        \r
        if (CompressionHeader->CompressionType == EFI_NOT_COMPRESSED) {\r
          //\r
          // stream is not actually compressed, just encapsulated.  So just copy it.\r
          //\r
          CopyMem (NewStreamBuffer, CompressionHeader + 1, NewStreamBufferSize);\r
        } else if (CompressionHeader->CompressionType == EFI_STANDARD_COMPRESSION) {\r
          //\r
          // Only support the EFI_SATNDARD_COMPRESSION algorithm.\r
          // \r
\r
          //\r
          // Decompress the stream\r
          //\r
          Status = gBS->LocateProtocol (&gEfiDecompressProtocolGuid, NULL, (VOID **)&Decompress);\r
          \r
          ASSERT_EFI_ERROR (Status);\r
          \r
          Status = Decompress->GetInfo (\r
                                 Decompress,\r
                                 CompressionHeader + 1,\r
                                 Node->Size - sizeof (EFI_COMPRESSION_SECTION),\r
                                 (UINT32 *)&NewStreamBufferSize,\r
                                 &ScratchSize\r
                                 );\r
          ASSERT_EFI_ERROR (Status);\r
          ASSERT (NewStreamBufferSize == CompressionHeader->UncompressedLength);\r
\r
          ScratchBuffer = AllocatePool (ScratchSize);\r
          if (ScratchBuffer == NULL) {\r
            gBS->FreePool (Node);\r
            gBS->FreePool (NewStreamBuffer);\r
            return EFI_OUT_OF_RESOURCES;\r
          }\r
\r
          Status = Decompress->Decompress (\r
                                 Decompress,\r
                                 CompressionHeader + 1,\r
                                 Node->Size - sizeof (EFI_COMPRESSION_SECTION),\r
                                 NewStreamBuffer,\r
                                 (UINT32)NewStreamBufferSize,\r
                                 ScratchBuffer,\r
                                 ScratchSize\r
                                 );\r
          ASSERT_EFI_ERROR (Status);\r
          gBS->FreePool (ScratchBuffer);                                           \r
        }\r
      } else {\r
        NewStreamBuffer = NULL;\r
        NewStreamBufferSize = 0;\r
      }\r
      \r
      Status = OpenSectionStreamEx (\r
                 NewStreamBufferSize,\r
                 NewStreamBuffer,\r
                 FALSE,\r
                 Stream->AuthenticationStatus,\r
                 &Node->EncapsulatedStreamHandle\r
                 );\r
      if (EFI_ERROR (Status)) {\r
        gBS->FreePool (Node);\r
        gBS->FreePool (NewStreamBuffer);\r
        return Status;\r
      }\r
      break;\r
\r
    case EFI_SECTION_GUID_DEFINED:\r
      GuidedHeader = (EFI_GUID_DEFINED_SECTION *) SectionHeader;\r
      Node->EncapsulationGuid = &GuidedHeader->SectionDefinitionGuid;\r
      Status = gBS->LocateProtocol (Node->EncapsulationGuid, NULL, (VOID **)&GuidedExtraction);\r
      if (!EFI_ERROR (Status)) {\r
        //\r
        // NewStreamBuffer is always allocated by ExtractSection... No caller\r
        // allocation here.\r
        //\r
        Status = GuidedExtraction->ExtractSection (\r
                                     GuidedExtraction,\r
                                     GuidedHeader,\r
                                     &NewStreamBuffer,\r
                                     &NewStreamBufferSize,\r
                                     &AuthenticationStatus\r
                                     );\r
        if (EFI_ERROR (Status)) {\r
          gBS->FreePool (*ChildNode);\r
          return EFI_PROTOCOL_ERROR;\r
        }\r
        \r
        //\r
        // Make sure we initialize the new stream with the correct \r
        // authentication status for both aggregate and local status fields.\r
        //\r
        if (GuidedHeader->Attributes & EFI_GUIDED_SECTION_AUTH_STATUS_VALID) {\r
          //\r
          // OR in the parent stream's aggregate status.\r
          //\r
          AuthenticationStatus |= Stream->AuthenticationStatus & EFI_AGGREGATE_AUTH_STATUS_ALL;\r
        } else {\r
          //\r
          // since there's no authentication data contributed by the section,\r
          // just inherit the full value from our immediate parent.\r
          //\r
          AuthenticationStatus = Stream->AuthenticationStatus;\r
        }\r
        \r
        Status = OpenSectionStreamEx (\r
                   NewStreamBufferSize,\r
                   NewStreamBuffer,\r
                   FALSE,\r
                   AuthenticationStatus,\r
                   &Node->EncapsulatedStreamHandle\r
                   );\r
        if (EFI_ERROR (Status)) {\r
          gBS->FreePool (*ChildNode);\r
          gBS->FreePool (NewStreamBuffer);\r
          return Status;\r
        }\r
      } else {\r
        //\r
        // There's no GUIDed section extraction protocol available.\r
        //\r
        if (GuidedHeader->Attributes & EFI_GUIDED_SECTION_PROCESSING_REQUIRED) {\r
          //\r
          // If the section REQUIRES an extraction protocol, then we're toast\r
          //\r
          gBS->FreePool (*ChildNode);\r
          return EFI_PROTOCOL_ERROR;\r
        }\r
        \r
        //\r
        // Figure out the proper authentication status\r
        //\r
        AuthenticationStatus = Stream->AuthenticationStatus;\r
        if (GuidedHeader->Attributes & EFI_GUIDED_SECTION_AUTH_STATUS_VALID) {\r
          //\r
          //  The local status of the new stream is contained in \r
          //  AuthenticaionStatus.  This value needs to be ORed into the\r
          //  Aggregate bits also...\r
          //\r
          \r
          //\r
          // Clear out and initialize the local status\r
          //\r
          AuthenticationStatus &= ~EFI_LOCAL_AUTH_STATUS_ALL;\r
          AuthenticationStatus |= EFI_LOCAL_AUTH_STATUS_IMAGE_SIGNED | EFI_LOCAL_AUTH_STATUS_NOT_TESTED;\r
          //\r
          // OR local status into aggregate status\r
          //\r
          AuthenticationStatus |= AuthenticationStatus >> 16;\r
        }\r
        \r
        SectionLength = SECTION_SIZE (GuidedHeader);\r
        Status = OpenSectionStreamEx (\r
                   SectionLength - GuidedHeader->DataOffset,\r
                   (UINT8 *) GuidedHeader + GuidedHeader->DataOffset,\r
                   TRUE,\r
                   AuthenticationStatus,\r
                   &Node->EncapsulatedStreamHandle\r
                   );\r
        if (EFI_ERROR (Status)) {\r
          gBS->FreePool (Node);\r
          return Status;\r
        }\r
      }\r
      \r
      if ((AuthenticationStatus & EFI_LOCAL_AUTH_STATUS_ALL) == \r
            (EFI_LOCAL_AUTH_STATUS_IMAGE_SIGNED | EFI_LOCAL_AUTH_STATUS_NOT_TESTED)) {\r
        //\r
        // Need to register for RPN for when the required GUIDed extraction\r
        // protocol becomes available.  This will enable us to refresh the\r
        // AuthenticationStatus cached in the Stream if it's ever requested\r
        // again.\r
        //\r
        CreateGuidedExtractionRpnEvent (Stream, Node);\r
      }\r
      \r
      break;\r
\r
    default:\r
      \r
      //\r
      // Nothing to do if it's a leaf\r
      //\r
      break;\r
  }\r
  \r
  //\r
  // Last, add the new child node to the stream\r
  //\r
  InsertTailList (&Stream->Children, &Node->Link);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Worker function.  Constructor for RPN event if needed to keep AuthenticationStatus\r
  cache correct when a missing GUIDED_SECTION_EXTRACTION_PROTOCOL appears...\r
\r
  @param ParentStream        - Indicates the parent of the ecnapsulation section (child)\r
  @param ChildNode           - Indicates the child node that is the encapsulation section.\r
\r
**/\r
STATIC\r
VOID\r
CreateGuidedExtractionRpnEvent (\r
  IN CORE_SECTION_STREAM_NODE       *ParentStream,\r
  IN CORE_SECTION_CHILD_NODE        *ChildNode\r
  )\r
{\r
  RPN_EVENT_CONTEXT *Context;\r
  \r
  //\r
  // Allocate new event structure and context\r
  //\r
  Context = AllocatePool (sizeof (RPN_EVENT_CONTEXT));\r
  ASSERT (Context != NULL);\r
  \r
  Context->ChildNode = ChildNode;\r
  Context->ParentStream = ParentStream;\r
 \r
  Context->Event = CoreCreateProtocolNotifyEvent (\r
                    Context->ChildNode->EncapsulationGuid,\r
                    TPL_NOTIFY,\r
                    NotifyGuidedExtraction,\r
                    Context,\r
                    &Context->Registration,\r
                    FALSE\r
                    );\r
}\r
  \r
/**\r
  RPN callback function.  Removes a stale section stream and re-initializes it\r
  with an updated AuthenticationStatus.\r
\r
  @param Event               - The event that fired\r
  @param RpnContext          - A pointer to the context that allows us to identify\r
                        the relevent encapsulation...\r
\r
**/  \r
STATIC\r
VOID\r
EFIAPI\r
NotifyGuidedExtraction (\r
  IN   EFI_EVENT   Event,\r
  IN   VOID        *RpnContext\r
  )\r
{\r
  EFI_STATUS                              Status;\r
  EFI_GUID_DEFINED_SECTION                *GuidedHeader;\r
  EFI_GUIDED_SECTION_EXTRACTION_PROTOCOL  *GuidedExtraction;\r
  VOID                                    *NewStreamBuffer;\r
  UINTN                                   NewStreamBufferSize;\r
  UINT32                                  AuthenticationStatus;\r
  RPN_EVENT_CONTEXT                       *Context;\r
  \r
  Context = RpnContext;\r
  \r
  Status = CloseSectionStream (&mSectionExtraction, Context->ChildNode->EncapsulatedStreamHandle);\r
  if (!EFI_ERROR (Status)) {\r
    //\r
    // The stream closed successfully, so re-open the stream with correct AuthenticationStatus\r
    //\r
  \r
    GuidedHeader = (EFI_GUID_DEFINED_SECTION *) \r
      (Context->ParentStream->StreamBuffer + Context->ChildNode->OffsetInStream);\r
    ASSERT (GuidedHeader->CommonHeader.Type == EFI_SECTION_GUID_DEFINED);\r
    \r
    Status = gBS->LocateProtocol (Context->ChildNode->EncapsulationGuid, NULL, (VOID **)&GuidedExtraction);\r
    ASSERT_EFI_ERROR (Status);\r
\r
    \r
    Status = GuidedExtraction->ExtractSection (\r
                                 GuidedExtraction,\r
                                 GuidedHeader,\r
                                 &NewStreamBuffer,\r
                                 &NewStreamBufferSize,\r
                                 &AuthenticationStatus\r
                                 );\r
    ASSERT_EFI_ERROR (Status);\r
    //\r
    // OR in the parent stream's aggregagate status.\r
    //\r
    AuthenticationStatus |= Context->ParentStream->AuthenticationStatus & EFI_AGGREGATE_AUTH_STATUS_ALL;\r
    Status = OpenSectionStreamEx (\r
               NewStreamBufferSize,\r
               NewStreamBuffer,\r
               FALSE,\r
               AuthenticationStatus,\r
               &Context->ChildNode->EncapsulatedStreamHandle\r
               );\r
    ASSERT_EFI_ERROR (Status);\r
  }\r
\r
  //\r
  //  If above, the stream  did not close successfully, it indicates it's\r
  //  alread been closed by someone, so just destroy the event and be done with\r
  //  it.\r
  //\r
  \r
  gBS->CloseEvent (Event);\r
  gBS->FreePool (Context);\r
}  \r
  \r
/**\r
  Worker function.  Destructor for child nodes.\r
\r
  @param ChildNode           - Indicates the node to destroy\r
\r
**/\r
STATIC\r
VOID\r
FreeChildNode (\r
  IN  CORE_SECTION_CHILD_NODE                   *ChildNode\r
  )\r
\r
{\r
  ASSERT (ChildNode->Signature == CORE_SECTION_CHILD_SIGNATURE);\r
  //\r
  // Remove the child from it's list\r
  //\r
  RemoveEntryList (&ChildNode->Link);\r
  \r
  if (ChildNode->EncapsulatedStreamHandle != NULL_STREAM_HANDLE) {\r
    //\r
    // If it's an encapsulating section, we close the resulting section stream.\r
    // CloseSectionStream will free all memory associated with the stream.\r
    //\r
    CloseSectionStream (&mSectionExtraction, ChildNode->EncapsulatedStreamHandle);\r
  }\r
  //\r
  // Last, free the child node itself\r
  //\r
  gBS->FreePool (ChildNode);\r
}  \r
\r
/**\r
  Worker function.  Constructor for section streams.\r
\r
  @param SectionStreamLength - Size in bytes of the section stream.\r
  @param SectionStream       - Buffer containing the new section stream.\r
  @param AllocateBuffer      - Indicates whether the stream buffer is to be copied\r
                          or the input buffer is to be used in place.\r
  @param AuthenticationStatus- Indicates the default authentication status for the\r
                          new stream.\r
  @param SectionStreamHandle - A pointer to a caller allocated section stream handle.\r
\r
  \r
  @retval EFI_SUCCESS         - Stream was added to stream database.\r
  @retval EFI_OUT_OF_RESOURCES - memory allocation failed.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
OpenSectionStreamEx (\r
  IN     UINTN                                     SectionStreamLength,\r
  IN     VOID                                      *SectionStream,\r
  IN     BOOLEAN                                   AllocateBuffer,\r
  IN     UINT32                                    AuthenticationStatus,   \r
     OUT UINTN                                     *SectionStreamHandle\r
  )\r
\r
{\r
  CORE_SECTION_STREAM_NODE    *NewStream;\r
  EFI_TPL                     OldTpl;\r
  \r
  //\r
  // Allocate a new stream\r
  //\r
  NewStream = AllocatePool (sizeof (CORE_SECTION_STREAM_NODE));\r
  if (NewStream == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
  \r
  if (AllocateBuffer) { \r
    //\r
    // if we're here, we're double buffering, allocate the buffer and copy the\r
    // data in\r
    //\r
    if (SectionStreamLength > 0) {\r
      NewStream->StreamBuffer = AllocatePool (SectionStreamLength); \r
      if (NewStream->StreamBuffer == NULL) {\r
        gBS->FreePool (NewStream);\r
        return EFI_OUT_OF_RESOURCES;\r
      }\r
      //\r
      // Copy in stream data\r
      //\r
      CopyMem (NewStream->StreamBuffer, SectionStream, SectionStreamLength);\r
    } else {\r
      //\r
      // It's possible to have a zero length section stream.\r
      //\r
      NewStream->StreamBuffer = NULL;\r
    }\r
  } else {\r
    //\r
    // If were here, the caller has supplied the buffer (it's an internal call)\r
    // so just assign the buffer.  This happens when we open section streams\r
    // as a result of expanding an encapsulating section.\r
    //\r
    NewStream->StreamBuffer = SectionStream;\r
  }\r
  \r
  //\r
  // Initialize the rest of the section stream\r
  //\r
  NewStream->Signature = CORE_SECTION_STREAM_SIGNATURE;\r
  NewStream->StreamHandle = (UINTN) NewStream;\r
  NewStream->StreamLength = SectionStreamLength;\r
  InitializeListHead (&NewStream->Children);\r
  NewStream->AuthenticationStatus = AuthenticationStatus;\r
  \r
  //\r
  // Add new stream to stream list\r
  //\r
  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);\r
  InsertTailList (&mStreamRoot, &NewStream->Link);\r
  gBS->RestoreTPL (OldTpl);\r
\r
  *SectionStreamHandle = NewStream->StreamHandle;\r
  \r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Worker function.  Search stream database for requested stream handle.\r
\r
  @param SearchHandle        - Indicates which stream to look for.\r
  @param FoundStream         - Output pointer to the found stream.\r
\r
  @retval EFI_SUCCESS         - StreamHandle was found and *FoundStream contains\r
                          the stream node.\r
  @retval EFI_NOT_FOUND       - SearchHandle was not found in the stream database.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
FindStreamNode (\r
  IN  UINTN                                     SearchHandle,\r
  OUT CORE_SECTION_STREAM_NODE                  **FoundStream\r
  )\r
\r
{  \r
  CORE_SECTION_STREAM_NODE                      *StreamNode;\r
  \r
  if (!IsListEmpty (&mStreamRoot)) {\r
    StreamNode = STREAM_NODE_FROM_LINK (GetFirstNode (&mStreamRoot));\r
    for (;;) {\r
      if (StreamNode->StreamHandle == SearchHandle) {\r
        *FoundStream = StreamNode;\r
        return EFI_SUCCESS;\r
      } else if (IsNodeAtEnd (&mStreamRoot, &StreamNode->Link)) {\r
        break;\r
      } else {\r
        StreamNode = STREAM_NODE_FROM_LINK (GetNextNode (&mStreamRoot, &StreamNode->Link));\r
      }\r
    }\r
  }\r
  \r
  return EFI_NOT_FOUND;\r
}\r
\r
/**\r
\r
  Check if a stream is valid.\r
\r
  @param SectionStream         - The section stream to be checked\r
  @param SectionStreamLength   - The length of section stream\r
\r
  @return if a stream is valid.\r
**/\r
STATIC\r
BOOLEAN\r
IsValidSectionStream (\r
  IN  VOID              *SectionStream,\r
  IN  UINTN             SectionStreamLength\r
  )\r
\r
{\r
  UINTN                       TotalLength;\r
  UINTN                       SectionLength;\r
  EFI_COMMON_SECTION_HEADER   *SectionHeader;\r
  EFI_COMMON_SECTION_HEADER   *NextSectionHeader;\r
\r
  TotalLength = 0;\r
  SectionHeader = (EFI_COMMON_SECTION_HEADER *)SectionStream;\r
  \r
  while (TotalLength < SectionStreamLength) {\r
    SectionLength = SECTION_SIZE (SectionHeader);\r
    TotalLength += SectionLength;\r
\r
    if (TotalLength == SectionStreamLength) {\r
      return TRUE;    \r
    }\r
\r
    //\r
    // Move to the next byte following the section...\r
    //\r
    SectionHeader = (EFI_COMMON_SECTION_HEADER *) ((UINT8 *) SectionHeader + SectionLength);\r
    \r
    //\r
    // Figure out where the next section begins\r
    //\r
    NextSectionHeader = (EFI_COMMON_SECTION_HEADER *) ((UINTN) SectionHeader + 3);\r
    NextSectionHeader = (EFI_COMMON_SECTION_HEADER *) ((UINTN) NextSectionHeader & ~(UINTN)3);\r
    TotalLength += (UINTN) NextSectionHeader - (UINTN) SectionHeader;\r
    SectionHeader = NextSectionHeader;\r
  }\r
\r
  ASSERT (FALSE);\r
  return FALSE;\r
}\r
\r
/**\r
  Create a protocol notification event and return it.\r
\r
  @param ProtocolGuid    - Protocol to register notification event on.\r
\r
  @param NotifyTpl        - Maximum TPL to signal the NotifyFunction.\r
\r
  @param NotifyFuncition  - EFI notification routine.\r
\r
  @param NotifyContext   - Context passed into Event when it is created.\r
\r
  @param Registration    - Registration key returned from RegisterProtocolNotify().\r
\r
  @param SignalFlag      -  Boolean value to decide whether kick the event after register or not.\r
\r
  @return  The EFI_EVENT that has been registered to be signaled when a ProtocolGuid\r
           is added to the system.\r
\r
**/\r
EFI_EVENT\r
CoreCreateProtocolNotifyEvent (\r
  IN EFI_GUID             *ProtocolGuid,\r
  IN EFI_TPL              NotifyTpl,\r
  IN EFI_EVENT_NOTIFY     NotifyFunction,\r
  IN VOID                 *NotifyContext,\r
  OUT VOID                **Registration,\r
  IN  BOOLEAN             SignalFlag\r
  )\r
{\r
  EFI_STATUS              Status;\r
  EFI_EVENT               Event;\r
\r
  //\r
  // Create the event\r
  //\r
\r
  Status = gBS->CreateEvent (\r
            EVT_NOTIFY_SIGNAL,\r
            NotifyTpl,\r
            NotifyFunction,\r
            NotifyContext,\r
           &Event\r
            );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Register for protocol notifactions on this event\r
  //\r
\r
  Status = gBS->RegisterProtocolNotify (\r
            ProtocolGuid,\r
            Event,\r
            Registration\r
            );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  if (SignalFlag) {\r
    //\r
    // Kick the event so we will perform an initial pass of\r
    // current installed drivers\r
    //\r
    gBS->SignalEvent (Event);\r
  }\r
\r
  return Event;\r
}\r
\r
\r