ShellProtocol.c

Go to the documentation of this file.

 
#include "Shell.h"
 
#define INIT_NAME_BUFFER_SIZE  128
 
EFI_STATUS
EFIAPI
EfiShellClose (
  IN SHELL_FILE_HANDLE  FileHandle
  )
{
  ShellFileHandleRemove (FileHandle);
  return (FileHandleClose (ConvertShellHandleToEfiFileProtocol (FileHandle)));
}
 
BOOLEAN
InternalShellProtocolIsBlockIoPresent (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePathCopy;
  EFI_STATUS                Status;
  EFI_HANDLE                Handle;
 
  Handle = NULL;
 
  DevicePathCopy = (EFI_DEVICE_PATH_PROTOCOL *)DevicePath;
  Status         = gBS->LocateDevicePath (&gEfiBlockIoProtocolGuid, &DevicePathCopy, &Handle);
 
  if ((Handle != NULL) && (!EFI_ERROR (Status))) {
    return (TRUE);
  }
 
  return (FALSE);
}
 
BOOLEAN
InternalShellProtocolIsSimpleFileSystemPresent (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePathCopy;
  EFI_STATUS                Status;
  EFI_HANDLE                Handle;
 
  Handle = NULL;
 
  DevicePathCopy = (EFI_DEVICE_PATH_PROTOCOL *)DevicePath;
  Status         = gBS->LocateDevicePath (&gEfiSimpleFileSystemProtocolGuid, &DevicePathCopy, &Handle);
 
  if ((Handle != NULL) && (!EFI_ERROR (Status))) {
    return (TRUE);
  }
 
  return (FALSE);
}
 
EFI_STATUS
EFIAPI
EfiShellSetMap (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath OPTIONAL,
  IN CONST CHAR16                    *Mapping
  )
{
  EFI_STATUS      Status;
  SHELL_MAP_LIST  *MapListNode;
 
  if (Mapping == NULL) {
    return (EFI_INVALID_PARAMETER);
  }
 
  if (Mapping[StrLen (Mapping)-1] != ':') {
    return (EFI_INVALID_PARAMETER);
  }
 
  //
  // Delete the mapping
  //
  if (DevicePath == NULL) {
    if (IsListEmpty (&gShellMapList.Link)) {
      return (EFI_NOT_FOUND);
    }
 
    for ( MapListNode = (SHELL_MAP_LIST *)GetFirstNode (&gShellMapList.Link)
          ; !IsNull (&gShellMapList.Link, &MapListNode->Link)
          ; MapListNode = (SHELL_MAP_LIST *)GetNextNode (&gShellMapList.Link, &MapListNode->Link)
          )
    {
      if (StringNoCaseCompare (&MapListNode->MapName, &Mapping) == 0) {
        RemoveEntryList (&MapListNode->Link);
        SHELL_FREE_NON_NULL (MapListNode->DevicePath);
        SHELL_FREE_NON_NULL (MapListNode->MapName);
        SHELL_FREE_NON_NULL (MapListNode->CurrentDirectoryPath);
        FreePool (MapListNode);
        return (EFI_SUCCESS);
      }
    } // for loop
 
    //
    // We didn't find one to delete
    //
    return (EFI_NOT_FOUND);
  }
 
  //
  // make sure this is a valid to add device path
  //
  if (  !InternalShellProtocolIsSimpleFileSystemPresent (DevicePath)
     && !InternalShellProtocolIsBlockIoPresent (DevicePath))
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  //
  // First make sure there is no old mapping
  //
  Status = EfiShellSetMap (NULL, Mapping);
  if ((Status != EFI_SUCCESS) && (Status != EFI_NOT_FOUND)) {
    return (Status);
  }
 
  //
  // now add the new one.
  //
  Status = ShellCommandAddMapItemAndUpdatePath (Mapping, DevicePath, 0, FALSE);
 
  return (Status);
}
 
CONST EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
EfiShellGetDevicePathFromMap (
  IN CONST CHAR16  *Mapping
  )
{
  SHELL_MAP_LIST  *MapListItem;
  CHAR16          *NewName;
  UINTN           Size;
 
  NewName = NULL;
  Size    = 0;
 
  StrnCatGrow (&NewName, &Size, Mapping, 0);
  if (Mapping[StrLen (Mapping)-1] != L':') {
    StrnCatGrow (&NewName, &Size, L":", 0);
  }
 
  MapListItem = ShellCommandFindMapItem (NewName);
 
  FreePool (NewName);
 
  if (MapListItem != NULL) {
    return (MapListItem->DevicePath);
  }
 
  return (NULL);
}
 
CONST CHAR16 *
EFIAPI
EfiShellGetMapFromDevicePath (
  IN OUT EFI_DEVICE_PATH_PROTOCOL  **DevicePath
  )
{
  SHELL_MAP_LIST  *Node;
  CHAR16          *PathForReturn;
  UINTN           PathSize;
 
  //  EFI_HANDLE                  PathHandle;
  //  EFI_HANDLE                  MapHandle;
  //  EFI_STATUS                  Status;
  //  EFI_DEVICE_PATH_PROTOCOL    *DevicePathCopy;
  //  EFI_DEVICE_PATH_PROTOCOL    *MapPathCopy;
 
  if ((DevicePath == NULL) || (*DevicePath == NULL)) {
    return (NULL);
  }
 
  PathForReturn = NULL;
  PathSize      = 0;
 
  for ( Node = (SHELL_MAP_LIST *)GetFirstNode (&gShellMapList.Link)
        ; !IsNull (&gShellMapList.Link, &Node->Link)
        ; Node = (SHELL_MAP_LIST *)GetNextNode (&gShellMapList.Link, &Node->Link)
        )
  {
    //
    // check for exact match
    //
    if (DevicePathCompare (DevicePath, &Node->DevicePath) == 0) {
      ASSERT ((PathForReturn == NULL && PathSize == 0) || (PathForReturn != NULL));
      if (PathSize != 0) {
        PathForReturn = StrnCatGrow (&PathForReturn, &PathSize, L";", 0);
      }
 
      PathForReturn = StrnCatGrow (&PathForReturn, &PathSize, Node->MapName, 0);
    }
  }
 
  if (PathForReturn != NULL) {
    while (!IsDevicePathEndType (*DevicePath)) {
      *DevicePath = NextDevicePathNode (*DevicePath);
    }
 
    //
    // Do not call SetDevicePathEndNode() if the device path node is already the
    // end of an entire device path.
    //
    if (!IsDevicePathEnd (*DevicePath)) {
      SetDevicePathEndNode (*DevicePath);
    }
  }
 
  /*
    if (PathForReturn == NULL) {
      PathSize = 0;
 
      DevicePathCopy = DuplicateDevicePath(*DevicePath);
      ASSERT(DevicePathCopy != NULL);
      Status = gBS->LocateDevicePath(&gEfiSimpleFileSystemProtocolGuid, &DevicePathCopy, &PathHandle);
      ASSERT_EFI_ERROR(Status);
      //
      //  check each of the device paths we have to get the root of the path for consist mappings
      //
      for ( Node = (SHELL_MAP_LIST *)GetFirstNode(&gShellMapList.Link)
          ; !IsNull(&gShellMapList.Link, &Node->Link)
          ; Node = (SHELL_MAP_LIST *)GetNextNode(&gShellMapList.Link, &Node->Link)
         ){
        if ((Node->Flags & SHELL_MAP_FLAGS_CONSIST) == 0) {
          continue;
        }
        MapPathCopy = DuplicateDevicePath(Node->DevicePath);
        ASSERT(MapPathCopy != NULL);
        Status = gBS->LocateDevicePath(&gEfiSimpleFileSystemProtocolGuid, &MapPathCopy, &MapHandle);
        if (MapHandle == PathHandle) {
 
          *DevicePath = DevicePathCopy;
 
          MapPathCopy = NULL;
          DevicePathCopy = NULL;
          PathForReturn = StrnCatGrow(&PathForReturn, &PathSize, Node->MapName, 0);
          PathForReturn = StrnCatGrow(&PathForReturn, &PathSize, L";", 0);
          break;
        }
      }
      //
      // now add on the non-consistent mappings
      //
      for ( Node = (SHELL_MAP_LIST *)GetFirstNode(&gShellMapList.Link)
          ; !IsNull(&gShellMapList.Link, &Node->Link)
          ; Node = (SHELL_MAP_LIST *)GetNextNode(&gShellMapList.Link, &Node->Link)
         ){
        if ((Node->Flags & SHELL_MAP_FLAGS_CONSIST) != 0) {
          continue;
        }
        MapPathCopy = Node->DevicePath;
        ASSERT(MapPathCopy != NULL);
        Status = gBS->LocateDevicePath(&gEfiSimpleFileSystemProtocolGuid, &MapPathCopy, &MapHandle);
        if (MapHandle == PathHandle) {
          PathForReturn = StrnCatGrow(&PathForReturn, &PathSize, Node->MapName, 0);
          PathForReturn = StrnCatGrow(&PathForReturn, &PathSize, L";", 0);
          break;
        }
      }
    }
  */
 
  return (AddBufferToFreeList (PathForReturn));
}
 
CHAR16 *
EFIAPI
EfiShellGetFilePathFromDevicePath (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *Path
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePathCopy;
  EFI_DEVICE_PATH_PROTOCOL  *MapPathCopy;
  SHELL_MAP_LIST            *MapListItem;
  CHAR16                    *PathForReturn;
  UINTN                     PathSize;
  EFI_HANDLE                PathHandle;
  EFI_HANDLE                MapHandle;
  EFI_STATUS                Status;
  FILEPATH_DEVICE_PATH      *FilePath;
  FILEPATH_DEVICE_PATH      *AlignedNode;
 
  PathForReturn = NULL;
  PathSize      = 0;
 
  DevicePathCopy = (EFI_DEVICE_PATH_PROTOCOL *)Path;
  ASSERT (DevicePathCopy != NULL);
  if (DevicePathCopy == NULL) {
    return (NULL);
  }
 
  Status = gBS->LocateDevicePath (&gEfiSimpleFileSystemProtocolGuid, &DevicePathCopy, &PathHandle);
 
  if (EFI_ERROR (Status)) {
    return (NULL);
  }
 
  //
  //  check each of the device paths we have to get the root of the path
  //
  for ( MapListItem = (SHELL_MAP_LIST *)GetFirstNode (&gShellMapList.Link)
        ; !IsNull (&gShellMapList.Link, &MapListItem->Link)
        ; MapListItem = (SHELL_MAP_LIST *)GetNextNode (&gShellMapList.Link, &MapListItem->Link)
        )
  {
    MapPathCopy = (EFI_DEVICE_PATH_PROTOCOL *)MapListItem->DevicePath;
    ASSERT (MapPathCopy != NULL);
    Status = gBS->LocateDevicePath (&gEfiSimpleFileSystemProtocolGuid, &MapPathCopy, &MapHandle);
    if (MapHandle == PathHandle) {
      ASSERT ((PathForReturn == NULL && PathSize == 0) || (PathForReturn != NULL));
      PathForReturn = StrnCatGrow (&PathForReturn, &PathSize, MapListItem->MapName, 0);
      //
      // go through all the remaining nodes in the device path
      //
      for ( FilePath = (FILEPATH_DEVICE_PATH *)DevicePathCopy
            ; !IsDevicePathEnd (&FilePath->Header)
            ; FilePath = (FILEPATH_DEVICE_PATH *)NextDevicePathNode (&FilePath->Header)
            )
      {
        //
        // If any node is not a file path node, then the conversion can not be completed
        //
        if ((DevicePathType (&FilePath->Header) != MEDIA_DEVICE_PATH) ||
            (DevicePathSubType (&FilePath->Header) != MEDIA_FILEPATH_DP))
        {
          if (PathForReturn != NULL) {
            FreePool (PathForReturn);
          }
 
          return NULL;
        }
 
        //
        // append the path part onto the filepath.
        //
        ASSERT ((PathForReturn == NULL && PathSize == 0) || (PathForReturn != NULL));
 
        AlignedNode = AllocateCopyPool (DevicePathNodeLength (FilePath), FilePath);
        if (AlignedNode == NULL) {
          if (PathForReturn != NULL) {
            FreePool (PathForReturn);
          }
 
          return NULL;
        }
 
        // File Path Device Path Nodes 'can optionally add a "\" separator to
        //  the beginning and/or the end of the Path Name string.'
        // (UEFI Spec 2.4 section 9.3.6.4).
        // If necessary, add a "\", but otherwise don't
        // (This is specified in the above section, and also implied by the
        //  UEFI Shell spec section 3.7)
        if ((PathSize != 0)                        &&
            (PathForReturn != NULL)                &&
            (PathForReturn[PathSize / sizeof (CHAR16) - 1] != L'\\') &&
            (AlignedNode->PathName[0]    != L'\\'))
        {
          PathForReturn = StrnCatGrow (&PathForReturn, &PathSize, L"\\", 1);
        }
 
        PathForReturn = StrnCatGrow (&PathForReturn, &PathSize, AlignedNode->PathName, 0);
        FreePool (AlignedNode);
      } // for loop of remaining nodes
    }
 
    if (PathForReturn != NULL) {
      break;
    }
  } // for loop of paths to check
 
  return (PathForReturn);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
EfiShellGetDevicePathFromFilePath (
  IN CONST CHAR16  *Path
  )
{
  CHAR16                          *MapName;
  CHAR16                          *NewPath;
  CONST CHAR16                    *Cwd;
  UINTN                           Size;
  CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_DEVICE_PATH_PROTOCOL        *DevicePathCopy;
  EFI_DEVICE_PATH_PROTOCOL        *DevicePathCopyForFree;
  EFI_DEVICE_PATH_PROTOCOL        *DevicePathForReturn;
  EFI_HANDLE                      Handle;
  EFI_STATUS                      Status;
 
  if (Path == NULL) {
    return (NULL);
  }
 
  MapName = NULL;
  NewPath = NULL;
 
  if (StrStr (Path, L":") == NULL) {
    Cwd = EfiShellGetCurDir (NULL);
    if (Cwd == NULL) {
      return (NULL);
    }
 
    Size    = StrSize (Cwd) + StrSize (Path);
    NewPath = AllocateZeroPool (Size);
    if (NewPath == NULL) {
      return (NULL);
    }
 
    StrCpyS (NewPath, Size/sizeof (CHAR16), Cwd);
    StrCatS (NewPath, Size/sizeof (CHAR16), L"\\");
    if (*Path == L'\\') {
      Path++;
      while (PathRemoveLastItem (NewPath)) {
      }
    }
 
    StrCatS (NewPath, Size/sizeof (CHAR16), Path);
    DevicePathForReturn = EfiShellGetDevicePathFromFilePath (NewPath);
    FreePool (NewPath);
    return (DevicePathForReturn);
  }
 
  Size = 0;
  //
  // find the part before (but including) the : for the map name
  //
  ASSERT ((MapName == NULL && Size == 0) || (MapName != NULL));
  MapName = StrnCatGrow (&MapName, &Size, Path, (StrStr (Path, L":")-Path+1));
  if ((MapName == NULL) || (MapName[StrLen (MapName)-1] != L':')) {
    return (NULL);
  }
 
  //
  // look up the device path in the map
  //
  DevicePath = EfiShellGetDevicePathFromMap (MapName);
  if (DevicePath == NULL) {
    //
    // Must have been a bad Mapname
    //
    return (NULL);
  }
 
  //
  // make a copy for LocateDevicePath to modify (also save a pointer to call FreePool with)
  //
  DevicePathCopyForFree = DevicePathCopy = DuplicateDevicePath (DevicePath);
  if (DevicePathCopy == NULL) {
    FreePool (MapName);
    return (NULL);
  }
 
  //
  // get the handle
  //
  Status = gBS->LocateDevicePath (&gEfiSimpleFileSystemProtocolGuid, &DevicePathCopy, &Handle);
  if (EFI_ERROR (Status)) {
    if (DevicePathCopyForFree != NULL) {
      FreePool (DevicePathCopyForFree);
    }
 
    FreePool (MapName);
    return (NULL);
  }
 
  //
  // build the full device path
  //
  if ((*(Path+StrLen (MapName)) != CHAR_NULL) &&
      (*(Path+StrLen (MapName)+1) == CHAR_NULL))
  {
    DevicePathForReturn = FileDevicePath (Handle, L"\\");
  } else {
    DevicePathForReturn = FileDevicePath (Handle, Path+StrLen (MapName));
  }
 
  FreePool (MapName);
  if (DevicePathCopyForFree != NULL) {
    FreePool (DevicePathCopyForFree);
  }
 
  return (DevicePathForReturn);
}
 
EFI_STATUS
EFIAPI
EfiShellGetDeviceName (
  IN EFI_HANDLE                   DeviceHandle,
  IN EFI_SHELL_DEVICE_NAME_FLAGS  Flags,
  IN CHAR8                        *Language,
  OUT CHAR16                      **BestDeviceName
  )
{
  EFI_STATUS                    Status;
  EFI_COMPONENT_NAME2_PROTOCOL  *CompName2;
  EFI_DEVICE_PATH_PROTOCOL      *DevicePath;
  EFI_HANDLE                    *HandleList;
  UINTN                         HandleCount;
  UINTN                         LoopVar;
  CHAR16                        *DeviceNameToReturn;
  CHAR8                         *Lang;
  UINTN                         ParentControllerCount;
  EFI_HANDLE                    *ParentControllerBuffer;
  UINTN                         ParentDriverCount;
  EFI_HANDLE                    *ParentDriverBuffer;
 
  if ((BestDeviceName == NULL) ||
      (DeviceHandle   == NULL)
      )
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  //
  // make sure one of the 2 supported bits is on
  //
  if (((Flags & EFI_DEVICE_NAME_USE_COMPONENT_NAME) == 0) &&
      ((Flags & EFI_DEVICE_NAME_USE_DEVICE_PATH) == 0))
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  DeviceNameToReturn = NULL;
  *BestDeviceName    = NULL;
  HandleList         = NULL;
  HandleCount        = 0;
  Lang               = NULL;
 
  if ((Flags & EFI_DEVICE_NAME_USE_COMPONENT_NAME) != 0) {
    Status = ParseHandleDatabaseByRelationship (
               NULL,
               DeviceHandle,
               HR_DRIVER_BINDING_HANDLE|HR_DEVICE_DRIVER,
               &HandleCount,
               &HandleList
               );
    for (LoopVar = 0; LoopVar < HandleCount; LoopVar++) {
      //
      // Go through those handles until we get one that passes for GetComponentName
      //
      Status = gBS->OpenProtocol (
                      HandleList[LoopVar],
                      &gEfiComponentName2ProtocolGuid,
                      (VOID **)&CompName2,
                      gImageHandle,
                      NULL,
                      EFI_OPEN_PROTOCOL_GET_PROTOCOL
                      );
      if (EFI_ERROR (Status)) {
        Status = gBS->OpenProtocol (
                        HandleList[LoopVar],
                        &gEfiComponentNameProtocolGuid,
                        (VOID **)&CompName2,
                        gImageHandle,
                        NULL,
                        EFI_OPEN_PROTOCOL_GET_PROTOCOL
                        );
      }
 
      if (EFI_ERROR (Status)) {
        continue;
      }
 
      Lang = GetBestLanguageForDriver (CompName2->SupportedLanguages, Language, FALSE);
      if (Lang == NULL) {
        continue;
      }
 
      Status = CompName2->GetControllerName (CompName2, DeviceHandle, NULL, Lang, &DeviceNameToReturn);
      FreePool (Lang);
      Lang = NULL;
      if (!EFI_ERROR (Status) && (DeviceNameToReturn != NULL)) {
        break;
      }
    }
 
    if (HandleList != NULL) {
      FreePool (HandleList);
    }
 
    //
    // Now check the parent controller using this as the child.
    //
    Status = PARSE_HANDLE_DATABASE_PARENTS (DeviceHandle, &ParentControllerCount, &ParentControllerBuffer);
    if ((DeviceNameToReturn == NULL) && !EFI_ERROR (Status)) {
      for (LoopVar = 0; LoopVar < ParentControllerCount; LoopVar++) {
        Status = PARSE_HANDLE_DATABASE_UEFI_DRIVERS (ParentControllerBuffer[LoopVar], &ParentDriverCount, &ParentDriverBuffer);
        if (!EFI_ERROR (Status)) {
          for (HandleCount = 0; HandleCount < ParentDriverCount; HandleCount++) {
            //
            // try using that driver's component name with controller and our driver as the child.
            //
            Status = gBS->OpenProtocol (
                            ParentDriverBuffer[HandleCount],
                            &gEfiComponentName2ProtocolGuid,
                            (VOID **)&CompName2,
                            gImageHandle,
                            NULL,
                            EFI_OPEN_PROTOCOL_GET_PROTOCOL
                            );
            if (EFI_ERROR (Status)) {
              Status = gBS->OpenProtocol (
                              ParentDriverBuffer[HandleCount],
                              &gEfiComponentNameProtocolGuid,
                              (VOID **)&CompName2,
                              gImageHandle,
                              NULL,
                              EFI_OPEN_PROTOCOL_GET_PROTOCOL
                              );
            }
 
            if (EFI_ERROR (Status)) {
              continue;
            }
 
            Lang = GetBestLanguageForDriver (CompName2->SupportedLanguages, Language, FALSE);
            if (Lang == NULL) {
              continue;
            }
 
            Status = CompName2->GetControllerName (CompName2, ParentControllerBuffer[LoopVar], DeviceHandle, Lang, &DeviceNameToReturn);
            FreePool (Lang);
            Lang = NULL;
            if (!EFI_ERROR (Status) && (DeviceNameToReturn != NULL)) {
              break;
            }
          }
 
          SHELL_FREE_NON_NULL (ParentDriverBuffer);
          if (!EFI_ERROR (Status) && (DeviceNameToReturn != NULL)) {
            break;
          }
        }
      }
 
      SHELL_FREE_NON_NULL (ParentControllerBuffer);
    }
 
    //
    // dont return on fail since we will try device path if that bit is on
    //
    if (DeviceNameToReturn != NULL) {
      ASSERT (BestDeviceName != NULL);
      StrnCatGrow (BestDeviceName, NULL, DeviceNameToReturn, 0);
      return (EFI_SUCCESS);
    }
  }
 
  if ((Flags & EFI_DEVICE_NAME_USE_DEVICE_PATH) != 0) {
    Status = gBS->OpenProtocol (
                    DeviceHandle,
                    &gEfiDevicePathProtocolGuid,
                    (VOID **)&DevicePath,
                    gImageHandle,
                    NULL,
                    EFI_OPEN_PROTOCOL_GET_PROTOCOL
                    );
    if (!EFI_ERROR (Status)) {
      //
      // use device path to text on the device path
      //
      *BestDeviceName = ConvertDevicePathToText (DevicePath, TRUE, TRUE);
      return (EFI_SUCCESS);
    }
  }
 
  //
  // none of the selected bits worked.
  //
  return (EFI_NOT_FOUND);
}
 
EFI_STATUS
EFIAPI
EfiShellOpenRootByHandle (
  IN EFI_HANDLE          DeviceHandle,
  OUT SHELL_FILE_HANDLE  *FileHandle
  )
{
  EFI_STATUS                       Status;
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL  *SimpleFileSystem;
  EFI_FILE_PROTOCOL                *RealFileHandle;
  EFI_DEVICE_PATH_PROTOCOL         *DevPath;
 
  //
  // get the simple file system interface
  //
  Status = gBS->OpenProtocol (
                  DeviceHandle,
                  &gEfiSimpleFileSystemProtocolGuid,
                  (VOID **)&SimpleFileSystem,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return (EFI_NOT_FOUND);
  }
 
  Status = gBS->OpenProtocol (
                  DeviceHandle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID **)&DevPath,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return (EFI_NOT_FOUND);
  }
 
  //
  // Open the root volume now...
  //
  Status = SimpleFileSystem->OpenVolume (SimpleFileSystem, &RealFileHandle);
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  *FileHandle = ConvertEfiFileProtocolToShellHandle (RealFileHandle, EfiShellGetMapFromDevicePath (&DevPath));
  return (EFI_SUCCESS);
}
 
EFI_STATUS
EFIAPI
EfiShellOpenRoot (
  IN EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  OUT SHELL_FILE_HANDLE        *FileHandle
  )
{
  EFI_STATUS  Status;
  EFI_HANDLE  Handle;
 
  if (FileHandle == NULL) {
    return (EFI_INVALID_PARAMETER);
  }
 
  //
  // find the handle of the device with that device handle and the file system
  //
  Status = gBS->LocateDevicePath (
                  &gEfiSimpleFileSystemProtocolGuid,
                  &DevicePath,
                  &Handle
                  );
  if (EFI_ERROR (Status)) {
    return (EFI_NOT_FOUND);
  }
 
  return (EfiShellOpenRootByHandle (Handle, FileHandle));
}
 
BOOLEAN
EFIAPI
EfiShellBatchIsActive (
  VOID
  )
{
  if (ShellCommandGetCurrentScriptFile () == NULL) {
    return (FALSE);
  }
 
  return (TRUE);
}
 
EFI_STATUS
InternalOpenFileDevicePath (
  IN OUT EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  OUT SHELL_FILE_HANDLE            *FileHandle,
  IN UINT64                        OpenMode,
  IN UINT64                        Attributes OPTIONAL
  )
{
  EFI_STATUS            Status;
  FILEPATH_DEVICE_PATH  *FilePathNode;
  EFI_HANDLE            Handle;
  SHELL_FILE_HANDLE     ShellHandle;
  EFI_FILE_PROTOCOL     *Handle1;
  EFI_FILE_PROTOCOL     *Handle2;
  FILEPATH_DEVICE_PATH  *AlignedNode;
 
  if (FileHandle == NULL) {
    return (EFI_INVALID_PARAMETER);
  }
 
  *FileHandle  = NULL;
  Handle1      = NULL;
  Handle2      = NULL;
  Handle       = NULL;
  ShellHandle  = NULL;
  FilePathNode = NULL;
  AlignedNode  = NULL;
 
  Status = EfiShellOpenRoot (DevicePath, &ShellHandle);
 
  if (!EFI_ERROR (Status)) {
    Handle1 = ConvertShellHandleToEfiFileProtocol (ShellHandle);
    if (Handle1 != NULL) {
      //
      // chop off the beginning part before the file system part...
      //
      Status = gBS->LocateDevicePath (
                      &gEfiSimpleFileSystemProtocolGuid,
                      &DevicePath,
                      &Handle
                      );
      if (!EFI_ERROR (Status)) {
        //
        // To access as a file system, the file path should only
        // contain file path components.  Follow the file path nodes
        // and find the target file
        //
        for ( FilePathNode = (FILEPATH_DEVICE_PATH *)DevicePath
              ; !IsDevicePathEnd (&FilePathNode->Header)
              ; FilePathNode = (FILEPATH_DEVICE_PATH *)NextDevicePathNode (&FilePathNode->Header)
              )
        {
          SHELL_FREE_NON_NULL (AlignedNode);
          AlignedNode = AllocateCopyPool (DevicePathNodeLength (FilePathNode), FilePathNode);
          //
          // For file system access each node should be a file path component
          //
          if ((DevicePathType (&FilePathNode->Header) != MEDIA_DEVICE_PATH) ||
              (DevicePathSubType (&FilePathNode->Header) != MEDIA_FILEPATH_DP)
              )
          {
            Status = EFI_UNSUPPORTED;
            break;
          }
 
          //
          // Open this file path node
          //
          Handle2 = Handle1;
          Handle1 = NULL;
 
          //
          // if this is the last node in the DevicePath always create (if that was requested).
          //
          if (IsDevicePathEnd ((NextDevicePathNode (&FilePathNode->Header)))) {
            Status = Handle2->Open (
                                Handle2,
                                &Handle1,
                                AlignedNode->PathName,
                                OpenMode,
                                Attributes
                                );
          } else {
            //
            //  This is not the last node and we dont want to 'create' existing
            //  directory entries...
            //
 
            //
            // open without letting it create
            // prevents error on existing files/directories
            //
            Status = Handle2->Open (
                                Handle2,
                                &Handle1,
                                AlignedNode->PathName,
                                OpenMode &~EFI_FILE_MODE_CREATE,
                                Attributes
                                );
            //
            // if above failed now open and create the 'item'
            // if OpenMode EFI_FILE_MODE_CREATE bit was on (but disabled above)
            //
            if ((EFI_ERROR (Status)) && ((OpenMode & EFI_FILE_MODE_CREATE) != 0)) {
              Status = Handle2->Open (
                                  Handle2,
                                  &Handle1,
                                  AlignedNode->PathName,
                                  OpenMode,
                                  Attributes
                                  );
            }
          }
 
          //
          // Close the last node
          //
          ShellInfoObject.NewEfiShellProtocol->CloseFile (Handle2);
 
          //
          // If there's been an error, stop
          //
          if (EFI_ERROR (Status)) {
            break;
          }
        } // for loop
      }
    }
  }
 
  SHELL_FREE_NON_NULL (AlignedNode);
  if (EFI_ERROR (Status)) {
    if (Handle1 != NULL) {
      ShellInfoObject.NewEfiShellProtocol->CloseFile (Handle1);
    }
  } else {
    *FileHandle = ConvertEfiFileProtocolToShellHandle (Handle1, ShellFileHandleGetPath (ShellHandle));
  }
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellCreateFile (
  IN CONST CHAR16        *FileName,
  IN UINT64              FileAttribs,
  OUT SHELL_FILE_HANDLE  *FileHandle
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_STATUS                Status;
  BOOLEAN                   Volatile;
 
  //
  // Is this for an environment variable
  // do we start with >v
  //
  if (StrStr (FileName, L">v") == FileName) {
    Status = IsVolatileEnv (FileName + 2, &Volatile);
    if (EFI_ERROR (Status)) {
      return Status;
    }
 
    if (!Volatile) {
      return (EFI_INVALID_PARAMETER);
    }
 
    *FileHandle = CreateFileInterfaceEnv (FileName+2);
    return (EFI_SUCCESS);
  }
 
  //
  // We are opening a regular file.
  //
  DevicePath = EfiShellGetDevicePathFromFilePath (FileName);
  if (DevicePath == NULL) {
    return (EFI_NOT_FOUND);
  }
 
  Status = InternalOpenFileDevicePath (DevicePath, FileHandle, EFI_FILE_MODE_READ|EFI_FILE_MODE_WRITE|EFI_FILE_MODE_CREATE, FileAttribs);
  FreePool (DevicePath);
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellRegisterGuidName (
  IN CONST EFI_GUID  *Guid,
  IN CONST CHAR16    *GuidName
  )
{
  return (AddNewGuidNameMapping (Guid, GuidName, NULL));
}
 
EFI_STATUS
EFIAPI
EfiShellOpenFileByName (
  IN CONST CHAR16        *FileName,
  OUT SHELL_FILE_HANDLE  *FileHandle,
  IN UINT64              OpenMode
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_STATUS                Status;
  BOOLEAN                   Volatile;
 
  *FileHandle = NULL;
 
  //
  // Is this for StdIn
  //
  if (StrCmp (FileName, L">i") == 0) {
    //
    // make sure not writing to StdIn
    //
    if ((OpenMode & EFI_FILE_MODE_WRITE) != 0) {
      return (EFI_INVALID_PARAMETER);
    }
 
    *FileHandle = ShellInfoObject.NewShellParametersProtocol->StdIn;
    ASSERT (*FileHandle != NULL);
    return (EFI_SUCCESS);
  }
 
  //
  // Is this for StdOut
  //
  if (StrCmp (FileName, L">o") == 0) {
    //
    // make sure not writing to StdIn
    //
    if ((OpenMode & EFI_FILE_MODE_READ) != 0) {
      return (EFI_INVALID_PARAMETER);
    }
 
    *FileHandle = &FileInterfaceStdOut;
    return (EFI_SUCCESS);
  }
 
  //
  // Is this for NUL / NULL file
  //
  if ((gUnicodeCollation->StriColl (gUnicodeCollation, (CHAR16 *)FileName, L"NUL") == 0) ||
      (gUnicodeCollation->StriColl (gUnicodeCollation, (CHAR16 *)FileName, L"NULL") == 0))
  {
    *FileHandle = &FileInterfaceNulFile;
    return (EFI_SUCCESS);
  }
 
  //
  // Is this for StdErr
  //
  if (StrCmp (FileName, L">e") == 0) {
    //
    // make sure not writing to StdIn
    //
    if ((OpenMode & EFI_FILE_MODE_READ) != 0) {
      return (EFI_INVALID_PARAMETER);
    }
 
    *FileHandle = &FileInterfaceStdErr;
    return (EFI_SUCCESS);
  }
 
  //
  // Is this for an environment variable
  // do we start with >v
  //
  if (StrStr (FileName, L">v") == FileName) {
    Status = IsVolatileEnv (FileName + 2, &Volatile);
    if (EFI_ERROR (Status)) {
      return Status;
    }
 
    if (!Volatile &&
        ((OpenMode & EFI_FILE_MODE_WRITE) != 0))
    {
      return (EFI_INVALID_PARAMETER);
    }
 
    *FileHandle = CreateFileInterfaceEnv (FileName+2);
    return (EFI_SUCCESS);
  }
 
  //
  // We are opening a regular file.
  //
  DevicePath = EfiShellGetDevicePathFromFilePath (FileName);
 
  if (DevicePath == NULL) {
    return (EFI_NOT_FOUND);
  }
 
  //
  // Copy the device path, open the file, then free the memory
  //
  Status = InternalOpenFileDevicePath (DevicePath, FileHandle, OpenMode, 0); // 0 = no specific file attributes
  FreePool (DevicePath);
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellDeleteFileByName (
  IN CONST CHAR16  *FileName
  )
{
  SHELL_FILE_HANDLE  FileHandle;
  EFI_STATUS         Status;
 
  FileHandle = NULL;
 
  //
  // get a handle to the file
  //
  Status = EfiShellCreateFile (
             FileName,
             0,
             &FileHandle
             );
  if (EFI_ERROR (Status)) {
    return (Status);
  }
 
  //
  // now delete the file
  //
  ShellFileHandleRemove (FileHandle);
  return (ShellInfoObject.NewEfiShellProtocol->DeleteFile (FileHandle));
}
 
VOID
EFIAPI
EfiShellDisablePageBreak (
  VOID
  )
{
  ShellInfoObject.PageBreakEnabled = FALSE;
}
 
VOID
EFIAPI
EfiShellEnablePageBreak (
  VOID
  )
{
  ShellInfoObject.PageBreakEnabled = TRUE;
}
 
EFI_STATUS
InternalShellExecuteDevicePath (
  IN CONST EFI_HANDLE                *ParentImageHandle,
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  IN CONST CHAR16                    *CommandLine OPTIONAL,
  IN CONST CHAR16                    **Environment OPTIONAL,
  OUT EFI_STATUS                     *StartImageStatus OPTIONAL
  )
{
  EFI_STATUS                     Status;
  EFI_STATUS                     StartStatus;
  EFI_STATUS                     CleanupStatus;
  EFI_HANDLE                     NewHandle;
  EFI_LOADED_IMAGE_PROTOCOL      *LoadedImage;
  LIST_ENTRY                     OrigEnvs;
  EFI_SHELL_PARAMETERS_PROTOCOL  ShellParamsProtocol;
  CHAR16                         *ImagePath;
  UINTN                          Index;
  CHAR16                         *Walker;
  CHAR16                         *NewCmdLine;
 
  if (ParentImageHandle == NULL) {
    return (EFI_INVALID_PARAMETER);
  }
 
  InitializeListHead (&OrigEnvs);
  ZeroMem (&ShellParamsProtocol, sizeof (EFI_SHELL_PARAMETERS_PROTOCOL));
 
  NewHandle = NULL;
 
  NewCmdLine = AllocateCopyPool (StrSize (CommandLine), CommandLine);
  if (NewCmdLine == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  for (Walker = NewCmdLine; Walker != NULL && *Walker != CHAR_NULL; Walker++) {
    if ((*Walker == L'^') && (*(Walker+1) == L'#')) {
      CopyMem (Walker, Walker+1, StrSize (Walker) - sizeof (Walker[0]));
    }
  }
 
  //
  // Load the image with:
  // FALSE - not from boot manager and NULL, 0 being not already in memory
  //
  Status = gBS->LoadImage (
                  FALSE,
                  *ParentImageHandle,
                  (EFI_DEVICE_PATH_PROTOCOL *)DevicePath,
                  NULL,
                  0,
                  &NewHandle
                  );
 
  if (EFI_ERROR (Status)) {
    if (NewHandle != NULL) {
      gBS->UnloadImage (NewHandle);
    }
 
    FreePool (NewCmdLine);
    return (Status);
  }
 
  Status = gBS->OpenProtocol (
                  NewHandle,
                  &gEfiLoadedImageProtocolGuid,
                  (VOID **)&LoadedImage,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
 
  if (!EFI_ERROR (Status)) {
    //
    // If the image is not an app abort it.
    //
    if (LoadedImage->ImageCodeType != EfiLoaderCode) {
      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_SHELL_IMAGE_NOT_APP),
        ShellInfoObject.HiiHandle
        );
      goto UnloadImage;
    }
 
    ASSERT (LoadedImage->LoadOptionsSize == 0);
    if (NewCmdLine != NULL) {
      LoadedImage->LoadOptionsSize = (UINT32)StrSize (NewCmdLine);
      LoadedImage->LoadOptions     = (VOID *)NewCmdLine;
    }
 
    //
    // Save our current environment settings for later restoration if necessary
    //
    if (Environment != NULL) {
      Status = GetEnvironmentVariableList (&OrigEnvs);
      if (!EFI_ERROR (Status)) {
        Status = SetEnvironmentVariables (Environment);
      }
    }
 
    //
    // Initialize and install a shell parameters protocol on the image.
    //
    ShellParamsProtocol.StdIn  = ShellInfoObject.NewShellParametersProtocol->StdIn;
    ShellParamsProtocol.StdOut = ShellInfoObject.NewShellParametersProtocol->StdOut;
    ShellParamsProtocol.StdErr = ShellInfoObject.NewShellParametersProtocol->StdErr;
    Status                     = UpdateArgcArgv (&ShellParamsProtocol, NewCmdLine, Efi_Application, NULL, NULL);
    if (EFI_ERROR (Status)) {
      goto UnloadImage;
    }
 
    //
    // Replace Argv[0] with the full path of the binary we're executing:
    // If the command line was "foo", the binary might be called "foo.efi".
    // "The first entry in [Argv] is always the full file path of the
    //  executable" - UEFI Shell Spec section 2.3
    //
    ImagePath = EfiShellGetFilePathFromDevicePath (DevicePath);
    // The image we're executing isn't necessarily in a filesystem - it might
    // be memory mapped. In this case EfiShellGetFilePathFromDevicePath will
    // return NULL, and we'll leave Argv[0] as UpdateArgcArgv set it.
    if (ImagePath != NULL) {
      if (ShellParamsProtocol.Argv == NULL) {
        // Command line was empty or null.
        // (UpdateArgcArgv sets Argv to NULL when CommandLine is "" or NULL)
        ShellParamsProtocol.Argv = AllocatePool (sizeof (CHAR16 *));
        if (ShellParamsProtocol.Argv == NULL) {
          Status = EFI_OUT_OF_RESOURCES;
          goto UnloadImage;
        }
 
        ShellParamsProtocol.Argc = 1;
      } else {
        // Free the string UpdateArgcArgv put in Argv[0];
        FreePool (ShellParamsProtocol.Argv[0]);
      }
 
      ShellParamsProtocol.Argv[0] = ImagePath;
    }
 
    Status = gBS->InstallProtocolInterface (&NewHandle, &gEfiShellParametersProtocolGuid, EFI_NATIVE_INTERFACE, &ShellParamsProtocol);
    ASSERT_EFI_ERROR (Status);
 
 
    //
    // now start the image and if the caller wanted the return code pass it to them...
    //
    if (!EFI_ERROR (Status)) {
      StartStatus = gBS->StartImage (
                           NewHandle,
                           0,
                           NULL
                           );
      if (StartImageStatus != NULL) {
        *StartImageStatus = StartStatus;
      }
 
      CleanupStatus = gBS->UninstallProtocolInterface (
                             NewHandle,
                             &gEfiShellParametersProtocolGuid,
                             &ShellParamsProtocol
                             );
      ASSERT_EFI_ERROR (CleanupStatus);
 
      goto FreeAlloc;
    }
 
UnloadImage:
    // Unload image - We should only get here if we didn't call StartImage
    gBS->UnloadImage (NewHandle);
 
FreeAlloc:
    // Free Argv (Allocated in UpdateArgcArgv)
    if (ShellParamsProtocol.Argv != NULL) {
      for (Index = 0; Index < ShellParamsProtocol.Argc; Index++) {
        if (ShellParamsProtocol.Argv[Index] != NULL) {
          FreePool (ShellParamsProtocol.Argv[Index]);
        }
      }
 
      FreePool (ShellParamsProtocol.Argv);
    }
  }
 
  // Restore environment variables
  if (!IsListEmpty (&OrigEnvs)) {
    CleanupStatus = SetEnvironmentVariableList (&OrigEnvs);
    ASSERT_EFI_ERROR (CleanupStatus);
  }
 
  FreePool (NewCmdLine);
 
  return (Status);
}
 
EFI_STATUS
InternalShellExecute (
  IN CONST CHAR16  *CommandLine OPTIONAL,
  IN CONST CHAR16  **Environment OPTIONAL,
  OUT EFI_STATUS   *StartImageStatus OPTIONAL
  )
{
  EFI_STATUS  Status;
  EFI_STATUS  CleanupStatus;
  LIST_ENTRY  OrigEnvs;
 
  InitializeListHead (&OrigEnvs);
 
  //
  // Save our current environment settings for later restoration if necessary
  //
  if (Environment != NULL) {
    Status = GetEnvironmentVariableList (&OrigEnvs);
    if (!EFI_ERROR (Status)) {
      Status = SetEnvironmentVariables (Environment);
    } else {
      return Status;
    }
  }
 
  Status = RunShellCommand (CommandLine, StartImageStatus);
 
  // Restore environment variables
  if (!IsListEmpty (&OrigEnvs)) {
    CleanupStatus = SetEnvironmentVariableList (&OrigEnvs);
    ASSERT_EFI_ERROR (CleanupStatus);
  }
 
  return (Status);
}
 
STATIC
BOOLEAN
NestingEnabled (
  VOID
  )
{
  EFI_STATUS  Status;
  CHAR16      *Temp;
  CHAR16      *Temp2;
  UINTN       TempSize;
  BOOLEAN     RetVal;
 
  RetVal = TRUE;
  Temp   = NULL;
  Temp2  = NULL;
 
  if (ShellInfoObject.ShellInitSettings.BitUnion.Bits.NoNest) {
    TempSize = 0;
    Temp     = NULL;
    Status   = SHELL_GET_ENVIRONMENT_VARIABLE (mNoNestingEnvVarName, &TempSize, Temp);
    if (Status == EFI_BUFFER_TOO_SMALL) {
      Temp = AllocateZeroPool (TempSize + sizeof (CHAR16));
      if (Temp != NULL) {
        Status = SHELL_GET_ENVIRONMENT_VARIABLE (mNoNestingEnvVarName, &TempSize, Temp);
      }
    }
 
    Temp2 = StrnCatGrow (&Temp2, NULL, mNoNestingTrue, 0);
    if ((Temp != NULL) && (Temp2 != NULL) && (StringNoCaseCompare (&Temp, &Temp2) == 0)) {
      //
      // Use the no nesting method.
      //
      RetVal = FALSE;
    }
  }
 
  SHELL_FREE_NON_NULL (Temp);
  SHELL_FREE_NON_NULL (Temp2);
  return (RetVal);
}
 
EFI_STATUS
EFIAPI
EfiShellExecute (
  IN EFI_HANDLE   *ParentImageHandle,
  IN CHAR16       *CommandLine OPTIONAL,
  IN CHAR16       **Environment OPTIONAL,
  OUT EFI_STATUS  *StatusCode OPTIONAL
  )
{
  EFI_STATUS                Status;
  CHAR16                    *Temp;
  EFI_DEVICE_PATH_PROTOCOL  *DevPath;
  UINTN                     Size;
 
  if ((PcdGet8 (PcdShellSupportLevel) < 1)) {
    return (EFI_UNSUPPORTED);
  }
 
  Temp = NULL;
  if (NestingEnabled ()) {
    DevPath = AppendDevicePath (ShellInfoObject.ImageDevPath, ShellInfoObject.FileDevPath);
    if (DevPath == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }
 
    DEBUG_CODE_BEGIN ();
    Temp = ConvertDevicePathToText (ShellInfoObject.FileDevPath, TRUE, TRUE);
    if (Temp != NULL) {
      FreePool (Temp);
    }
 
    Temp = ConvertDevicePathToText (ShellInfoObject.ImageDevPath, TRUE, TRUE);
    if (Temp != NULL) {
      FreePool (Temp);
    }
 
    if (DevPath != NULL) {
      Temp = ConvertDevicePathToText (DevPath, TRUE, TRUE);
    }
 
    if (Temp != NULL) {
      FreePool (Temp);
    }
 
    DEBUG_CODE_END ();
 
    Temp = NULL;
    Size = 0;
    ASSERT ((Temp == NULL && Size == 0) || (Temp != NULL));
    StrnCatGrow (&Temp, &Size, L"Shell.efi -exit ", 0);
    StrnCatGrow (&Temp, &Size, CommandLine, 0);
 
    Status = InternalShellExecuteDevicePath (
               ParentImageHandle,
               DevPath,
               Temp,
               (CONST CHAR16 **)Environment,
               StatusCode
               );
 
    //
    // de-allocate and return
    //
    FreePool (DevPath);
    FreePool (Temp);
  } else {
    Status = InternalShellExecute (
               (CONST CHAR16 *)CommandLine,
               (CONST CHAR16 **)Environment,
               StatusCode
               );
  }
 
  return (Status);
}
 
VOID
InternalFreeShellFileInfoNode (
  IN EFI_SHELL_FILE_INFO  *FileListNode
  )
{
  if (FileListNode->Info != NULL) {
    FreePool ((VOID *)FileListNode->Info);
  }
 
  if (FileListNode->FileName != NULL) {
    FreePool ((VOID *)FileListNode->FileName);
  }
 
  if (FileListNode->FullName != NULL) {
    FreePool ((VOID *)FileListNode->FullName);
  }
 
  if (FileListNode->Handle != NULL) {
    ShellInfoObject.NewEfiShellProtocol->CloseFile (FileListNode->Handle);
  }
 
  FreePool (FileListNode);
}
 
EFI_STATUS
EFIAPI
EfiShellFreeFileList (
  IN EFI_SHELL_FILE_INFO  **FileList
  )
{
  EFI_SHELL_FILE_INFO  *ShellFileListItem;
 
  if ((FileList == NULL) || (*FileList == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  for ( ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetFirstNode (&(*FileList)->Link)
        ; !IsListEmpty (&(*FileList)->Link)
        ; ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetFirstNode (&(*FileList)->Link)
        )
  {
    RemoveEntryList (&ShellFileListItem->Link);
    InternalFreeShellFileInfoNode (ShellFileListItem);
  }
 
  InternalFreeShellFileInfoNode (*FileList);
  *FileList = NULL;
  return (EFI_SUCCESS);
}
 
EFI_STATUS
EFIAPI
EfiShellRemoveDupInFileList (
  IN EFI_SHELL_FILE_INFO  **FileList
  )
{
  EFI_STATUS           Status;
  EFI_SHELL_FILE_INFO  *Duplicates;
  EFI_SHELL_FILE_INFO  *ShellFileListItem;
  EFI_SHELL_FILE_INFO  *ShellFileListItem2;
  EFI_SHELL_FILE_INFO  *TempNode;
 
  if ((FileList == NULL) || (*FileList == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  Status = ShellSortFileList (
             FileList,
             &Duplicates,
             ShellSortFileListByFullName
             );
  if (!EFI_ERROR (Status)) {
    EfiShellFreeFileList (&Duplicates);
    return EFI_SUCCESS;
  }
 
  //
  // Fall back to the slow method that needs no extra memory, and so cannot
  // fail.
  //
  for ( ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetFirstNode (&(*FileList)->Link)
        ; !IsNull (&(*FileList)->Link, &ShellFileListItem->Link)
        ; ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetNextNode (&(*FileList)->Link, &ShellFileListItem->Link)
        )
  {
    for ( ShellFileListItem2 = (EFI_SHELL_FILE_INFO *)GetNextNode (&(*FileList)->Link, &ShellFileListItem->Link)
          ; !IsNull (&(*FileList)->Link, &ShellFileListItem2->Link)
          ; ShellFileListItem2 = (EFI_SHELL_FILE_INFO *)GetNextNode (&(*FileList)->Link, &ShellFileListItem2->Link)
          )
    {
      if (gUnicodeCollation->StriColl (
                               gUnicodeCollation,
                               (CHAR16 *)ShellFileListItem->FullName,
                               (CHAR16 *)ShellFileListItem2->FullName
                               ) == 0
          )
      {
        TempNode = (EFI_SHELL_FILE_INFO *)GetPreviousNode (
                                            &(*FileList)->Link,
                                            &ShellFileListItem2->Link
                                            );
        RemoveEntryList (&ShellFileListItem2->Link);
        InternalFreeShellFileInfoNode (ShellFileListItem2);
        // Set ShellFileListItem2 to PreviousNode so we don't access Freed
        // memory in GetNextNode in the loop expression above.
        ShellFileListItem2 = TempNode;
      }
    }
  }
 
  return (EFI_SUCCESS);
}
 
//
// This is the same structure as the external version, but it has no CONST qualifiers.
//
typedef struct {
  LIST_ENTRY           Link;      
  EFI_STATUS           Status;    
  CHAR16               *FullName; 
  CHAR16               *FileName; 
  SHELL_FILE_HANDLE    Handle;    
  EFI_FILE_INFO        *Info;     
} EFI_SHELL_FILE_INFO_NO_CONST;
 
EFI_SHELL_FILE_INFO *
InternalDuplicateShellFileInfo (
  IN       EFI_SHELL_FILE_INFO  *Node,
  IN BOOLEAN                    Save
  )
{
  EFI_SHELL_FILE_INFO_NO_CONST  *NewNode;
 
  //
  // try to confirm that the objects are in sync
  //
  ASSERT (sizeof (EFI_SHELL_FILE_INFO_NO_CONST) == sizeof (EFI_SHELL_FILE_INFO));
 
  NewNode = AllocateZeroPool (sizeof (EFI_SHELL_FILE_INFO));
  if (NewNode == NULL) {
    return (NULL);
  }
 
  NewNode->FullName = AllocateCopyPool (StrSize (Node->FullName), Node->FullName);
  NewNode->FileName = AllocateCopyPool (StrSize (Node->FileName), Node->FileName);
  NewNode->Info     = AllocateCopyPool ((UINTN)Node->Info->Size, Node->Info);
  if (  (NewNode->FullName == NULL)
     || (NewNode->FileName == NULL)
     || (NewNode->Info == NULL)
        )
  {
    SHELL_FREE_NON_NULL (NewNode->FullName);
    SHELL_FREE_NON_NULL (NewNode->FileName);
    SHELL_FREE_NON_NULL (NewNode->Info);
    SHELL_FREE_NON_NULL (NewNode);
    return (NULL);
  }
 
  NewNode->Status = Node->Status;
  NewNode->Handle = Node->Handle;
  if (!Save) {
    Node->Handle = NULL;
  }
 
  return ((EFI_SHELL_FILE_INFO *)NewNode);
}
 
EFI_SHELL_FILE_INFO *
CreateAndPopulateShellFileInfo (
  IN CONST CHAR16             *BasePath,
  IN CONST EFI_STATUS         Status,
  IN CONST CHAR16             *FileName,
  IN CONST SHELL_FILE_HANDLE  Handle,
  IN CONST EFI_FILE_INFO      *Info
  )
{
  EFI_SHELL_FILE_INFO  *ShellFileListItem;
  CHAR16               *TempString;
  UINTN                Size;
 
  TempString = NULL;
  Size       = 0;
 
  ShellFileListItem = AllocateZeroPool (sizeof (EFI_SHELL_FILE_INFO));
  if (ShellFileListItem == NULL) {
    return (NULL);
  }
 
  if ((Info != NULL) && (Info->Size != 0)) {
    ShellFileListItem->Info = AllocateZeroPool ((UINTN)Info->Size);
    if (ShellFileListItem->Info == NULL) {
      FreePool (ShellFileListItem);
      return (NULL);
    }
 
    CopyMem (ShellFileListItem->Info, Info, (UINTN)Info->Size);
  } else {
    ShellFileListItem->Info = NULL;
  }
 
  if (FileName != NULL) {
    ASSERT (TempString == NULL);
    ShellFileListItem->FileName = StrnCatGrow (&TempString, 0, FileName, 0);
    if (ShellFileListItem->FileName == NULL) {
      FreePool (ShellFileListItem->Info);
      FreePool (ShellFileListItem);
      return (NULL);
    }
  } else {
    ShellFileListItem->FileName = NULL;
  }
 
  Size       = 0;
  TempString = NULL;
  if (BasePath != NULL) {
    ASSERT ((TempString == NULL && Size == 0) || (TempString != NULL));
    TempString = StrnCatGrow (&TempString, &Size, BasePath, 0);
    if (TempString == NULL) {
      FreePool ((VOID *)ShellFileListItem->FileName);
      SHELL_FREE_NON_NULL (ShellFileListItem->Info);
      FreePool (ShellFileListItem);
      return (NULL);
    }
  }
 
  if (ShellFileListItem->FileName != NULL) {
    ASSERT ((TempString == NULL && Size == 0) || (TempString != NULL));
    TempString = StrnCatGrow (&TempString, &Size, ShellFileListItem->FileName, 0);
    if (TempString == NULL) {
      FreePool ((VOID *)ShellFileListItem->FileName);
      FreePool (ShellFileListItem->Info);
      FreePool (ShellFileListItem);
      return (NULL);
    }
  }
 
  TempString = PathCleanUpDirectories (TempString);
 
  ShellFileListItem->FullName = TempString;
  ShellFileListItem->Status   = Status;
  ShellFileListItem->Handle   = Handle;
 
  return (ShellFileListItem);
}
 
EFI_STATUS
EFIAPI
EfiShellFindFilesInDir (
  IN SHELL_FILE_HANDLE     FileDirHandle,
  OUT EFI_SHELL_FILE_INFO  **FileList
  )
{
  EFI_SHELL_FILE_INFO  *ShellFileList;
  EFI_SHELL_FILE_INFO  *ShellFileListItem;
  EFI_FILE_INFO        *FileInfo;
  EFI_STATUS           Status;
  BOOLEAN              NoFile;
  CHAR16               *TempString;
  CHAR16               *BasePath;
  UINTN                Size;
  CHAR16               *TempSpot;
 
  BasePath = NULL;
  Status   = FileHandleGetFileName (FileDirHandle, &BasePath);
  if (EFI_ERROR (Status)) {
    return (Status);
  }
 
  if (ShellFileHandleGetPath (FileDirHandle) != NULL) {
    TempString = NULL;
    Size       = 0;
    TempString = StrnCatGrow (&TempString, &Size, ShellFileHandleGetPath (FileDirHandle), 0);
    if (TempString == NULL) {
      SHELL_FREE_NON_NULL (BasePath);
      return (EFI_OUT_OF_RESOURCES);
    }
 
    TempSpot = StrStr (TempString, L";");
 
    if (TempSpot != NULL) {
      *TempSpot = CHAR_NULL;
    }
 
    TempString = StrnCatGrow (&TempString, &Size, BasePath, 0);
    if (TempString == NULL) {
      SHELL_FREE_NON_NULL (BasePath);
      return (EFI_OUT_OF_RESOURCES);
    }
 
    SHELL_FREE_NON_NULL (BasePath);
    BasePath = TempString;
  }
 
  NoFile            = FALSE;
  ShellFileList     = NULL;
  ShellFileListItem = NULL;
  FileInfo          = NULL;
  Status            = EFI_SUCCESS;
 
  for ( Status = FileHandleFindFirstFile (FileDirHandle, &FileInfo)
        ; !EFI_ERROR (Status) && !NoFile
        ; Status = FileHandleFindNextFile (FileDirHandle, FileInfo, &NoFile)
        )
  {
    if (ShellFileList == NULL) {
      ShellFileList = (EFI_SHELL_FILE_INFO *)AllocateZeroPool (sizeof (EFI_SHELL_FILE_INFO));
      if (ShellFileList == NULL) {
        SHELL_FREE_NON_NULL (BasePath);
        return EFI_OUT_OF_RESOURCES;
      }
 
      InitializeListHead (&ShellFileList->Link);
    }
 
    //
    // allocate a new EFI_SHELL_FILE_INFO and populate it...
    //
    ShellFileListItem = CreateAndPopulateShellFileInfo (
                          BasePath,
                          EFI_SUCCESS, // success since we didn't fail to open it...
                          FileInfo->FileName,
                          NULL, // no handle since not open
                          FileInfo
                          );
    if (ShellFileListItem == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      //
      // Free resources outside the loop.
      //
      break;
    }
 
    InsertTailList (&ShellFileList->Link, &ShellFileListItem->Link);
  }
 
  if (EFI_ERROR (Status)) {
    EfiShellFreeFileList (&ShellFileList);
    *FileList = NULL;
  } else {
    *FileList = ShellFileList;
  }
 
  SHELL_FREE_NON_NULL (BasePath);
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellGetGuidFromName (
  IN  CONST CHAR16    *GuidName,
  OUT       EFI_GUID  *Guid
  )
{
  EFI_GUID    *NewGuid;
  EFI_STATUS  Status;
 
  if ((Guid == NULL) || (GuidName == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  Status = GetGuidFromStringName (GuidName, NULL, &NewGuid);
 
  if (!EFI_ERROR (Status)) {
    CopyGuid (Guid, NewGuid);
  }
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellGetGuidName (
  IN  CONST EFI_GUID  *Guid,
  OUT CONST CHAR16    **GuidName
  )
{
  CHAR16  *Name;
 
  if ((Guid == NULL) || (GuidName == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  Name = GetStringNameFromGuid (Guid, NULL);
  if ((Name == NULL) || (StrLen (Name) == 0)) {
    SHELL_FREE_NON_NULL (Name);
    return (EFI_NOT_FOUND);
  }
 
  *GuidName = AddBufferToFreeList (Name);
 
  return (EFI_SUCCESS);
}
 
EFI_STATUS
ShellSearchHandle (
  IN     CONST CHAR16                          *FilePattern,
  IN           EFI_UNICODE_COLLATION_PROTOCOL  *UnicodeCollation,
  IN           SHELL_FILE_HANDLE               FileHandle,
  IN OUT       EFI_SHELL_FILE_INFO             **FileList,
  IN     CONST EFI_SHELL_FILE_INFO             *ParentNode OPTIONAL,
  IN     CONST CHAR16                          *MapName
  )
{
  EFI_STATUS           Status;
  CONST CHAR16         *NextFilePatternStart;
  CHAR16               *CurrentFilePattern;
  EFI_SHELL_FILE_INFO  *ShellInfo;
  EFI_SHELL_FILE_INFO  *ShellInfoNode;
  EFI_SHELL_FILE_INFO  *NewShellNode;
  EFI_FILE_INFO        *FileInfo;
  BOOLEAN              Directory;
  CHAR16               *NewFullName;
  UINTN                Size;
 
  NewShellNode = NULL;
  FileInfo     = NULL;
  if (  (FilePattern      == NULL)
     || (UnicodeCollation == NULL)
     || (FileList         == NULL)
        )
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  ShellInfo          = NULL;
  CurrentFilePattern = NULL;
 
  if (*FilePattern == L'\\') {
    FilePattern++;
  }
 
  for ( NextFilePatternStart = FilePattern
        ; *NextFilePatternStart != CHAR_NULL && *NextFilePatternStart != L'\\'
        ; NextFilePatternStart++)
  {
  }
 
  CurrentFilePattern = AllocateZeroPool ((NextFilePatternStart-FilePattern+1)*sizeof (CHAR16));
  if (CurrentFilePattern == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  StrnCpyS (CurrentFilePattern, NextFilePatternStart-FilePattern+1, FilePattern, NextFilePatternStart-FilePattern);
 
  if (  (CurrentFilePattern[0]   == CHAR_NULL)
     && (NextFilePatternStart[0] == CHAR_NULL)
        )
  {
    //
    // we want the parent or root node (if no parent)
    //
    if (ParentNode == NULL) {
      //
      // We want the root node.  create the node.
      //
      FileInfo = FileHandleGetInfo (FileHandle);
      if (FileInfo != NULL) {
        NewShellNode = CreateAndPopulateShellFileInfo (
                         MapName,
                         EFI_SUCCESS,
                         L"\\",
                         FileHandle,
                         FileInfo
                         );
      }
 
      SHELL_FREE_NON_NULL (FileInfo);
    } else {
      //
      // Add the current parameter FileHandle to the list, then end...
      //
      NewShellNode = InternalDuplicateShellFileInfo ((EFI_SHELL_FILE_INFO *)ParentNode, TRUE);
    }
 
    if (NewShellNode == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
    } else {
      NewShellNode->Handle = NULL;
      if (*FileList == NULL) {
        *FileList = AllocateZeroPool (sizeof (EFI_SHELL_FILE_INFO));
        InitializeListHead (&((*FileList)->Link));
      }
 
      //
      // Add to the returning to use list
      //
      InsertTailList (&(*FileList)->Link, &NewShellNode->Link);
 
      Status = EFI_SUCCESS;
    }
  } else {
    Status = EfiShellFindFilesInDir (FileHandle, &ShellInfo);
 
    if (!EFI_ERROR (Status)) {
      if (StrStr (NextFilePatternStart, L"\\") != NULL) {
        Directory = TRUE;
      } else {
        Directory = FALSE;
      }
 
      for ( ShellInfoNode = (EFI_SHELL_FILE_INFO *)GetFirstNode (&ShellInfo->Link)
            ; !IsNull (&ShellInfo->Link, &ShellInfoNode->Link)
            ; ShellInfoNode = (EFI_SHELL_FILE_INFO *)GetNextNode (&ShellInfo->Link, &ShellInfoNode->Link)
            )
      {
        if (UnicodeCollation->MetaiMatch (UnicodeCollation, (CHAR16 *)ShellInfoNode->FileName, CurrentFilePattern)) {
          if ((ShellInfoNode->FullName != NULL) && (StrStr (ShellInfoNode->FullName, L":") == NULL)) {
            Size        = StrSize (ShellInfoNode->FullName) + StrSize (MapName);
            NewFullName = AllocateZeroPool (Size);
            if (NewFullName == NULL) {
              Status = EFI_OUT_OF_RESOURCES;
            } else {
              StrCpyS (NewFullName, Size / sizeof (CHAR16), MapName);
              StrCatS (NewFullName, Size / sizeof (CHAR16), ShellInfoNode->FullName);
              FreePool ((VOID *)ShellInfoNode->FullName);
              ShellInfoNode->FullName = NewFullName;
            }
          }
 
          if (Directory && !EFI_ERROR (Status) && (ShellInfoNode->FullName != NULL) && (ShellInfoNode->FileName != NULL)) {
            //
            // should be a directory
            //
 
            //
            // don't open the . and .. directories
            //
            if (  (StrCmp (ShellInfoNode->FileName, L".") != 0)
               && (StrCmp (ShellInfoNode->FileName, L"..") != 0)
                  )
            {
              //
              //
              //
              if (EFI_ERROR (Status)) {
                break;
              }
 
              //
              // Open the directory since we need that handle in the next recursion.
              //
              ShellInfoNode->Status = EfiShellOpenFileByName (ShellInfoNode->FullName, &ShellInfoNode->Handle, EFI_FILE_MODE_READ);
 
              //
              // recurse with the next part of the pattern
              //
              Status = ShellSearchHandle (NextFilePatternStart, UnicodeCollation, ShellInfoNode->Handle, FileList, ShellInfoNode, MapName);
              EfiShellClose (ShellInfoNode->Handle);
              ShellInfoNode->Handle = NULL;
            }
          } else if (!EFI_ERROR (Status)) {
            //
            // should be a file
            //
 
            //
            // copy the information we need into a new Node
            //
            NewShellNode = InternalDuplicateShellFileInfo (ShellInfoNode, FALSE);
            if (NewShellNode == NULL) {
              Status = EFI_OUT_OF_RESOURCES;
            }
 
            if (*FileList == NULL) {
              *FileList = AllocateZeroPool (sizeof (EFI_SHELL_FILE_INFO));
              InitializeListHead (&((*FileList)->Link));
            }
 
            //
            // Add to the returning to use list
            //
            InsertTailList (&(*FileList)->Link, &NewShellNode->Link);
          }
        }
 
        if (EFI_ERROR (Status)) {
          break;
        }
      }
 
      if (EFI_ERROR (Status)) {
        EfiShellFreeFileList (&ShellInfo);
      } else {
        Status = EfiShellFreeFileList (&ShellInfo);
      }
    }
  }
 
  if ((*FileList == NULL) || ((*FileList != NULL) && IsListEmpty (&(*FileList)->Link))) {
    Status = EFI_NOT_FOUND;
  }
 
  FreePool (CurrentFilePattern);
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellFindFiles (
  IN CONST CHAR16          *FilePattern,
  OUT EFI_SHELL_FILE_INFO  **FileList
  )
{
  EFI_STATUS                Status;
  CHAR16                    *PatternCopy;
  CHAR16                    *PatternCurrentLocation;
  EFI_DEVICE_PATH_PROTOCOL  *RootDevicePath;
  SHELL_FILE_HANDLE         RootFileHandle;
  CHAR16                    *MapName;
  UINTN                     Count;
 
  if (  (FilePattern      == NULL)
     || (FileList         == NULL)
     || (StrStr (FilePattern, L":") == NULL)
        )
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  Status         = EFI_SUCCESS;
  RootDevicePath = NULL;
  RootFileHandle = NULL;
  MapName        = NULL;
  PatternCopy    = AllocateCopyPool (StrSize (FilePattern), FilePattern);
  if (PatternCopy == NULL) {
    return (EFI_OUT_OF_RESOURCES);
  }
 
  PatternCopy = PathCleanUpDirectories (PatternCopy);
  if (PatternCopy == NULL) {
    return (EFI_OUT_OF_RESOURCES);
  }
 
  Count = StrStr (PatternCopy, L":") - PatternCopy + 1;
  ASSERT (Count <= StrLen (PatternCopy));
 
  ASSERT (MapName == NULL);
  MapName = StrnCatGrow (&MapName, NULL, PatternCopy, Count);
  if (MapName == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
  } else {
    RootDevicePath = EfiShellGetDevicePathFromFilePath (PatternCopy);
    if (RootDevicePath == NULL) {
      Status = EFI_INVALID_PARAMETER;
    } else {
      Status = EfiShellOpenRoot (RootDevicePath, &RootFileHandle);
      if (!EFI_ERROR (Status)) {
        for ( PatternCurrentLocation = PatternCopy
              ; *PatternCurrentLocation != ':'
              ; PatternCurrentLocation++)
        {
        }
 
        PatternCurrentLocation++;
        Status = ShellSearchHandle (PatternCurrentLocation, gUnicodeCollation, RootFileHandle, FileList, NULL, MapName);
        EfiShellClose (RootFileHandle);
      }
 
      FreePool (RootDevicePath);
    }
  }
 
  SHELL_FREE_NON_NULL (PatternCopy);
  SHELL_FREE_NON_NULL (MapName);
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
EfiShellOpenFileList (
  IN CHAR16                   *Path,
  IN UINT64                   OpenMode,
  IN OUT EFI_SHELL_FILE_INFO  **FileList
  )
{
  EFI_STATUS           Status;
  EFI_SHELL_FILE_INFO  *ShellFileListItem;
  CHAR16               *Path2;
  UINTN                Path2Size;
  CONST CHAR16         *CurDir;
  BOOLEAN              Found;
 
  PathCleanUpDirectories (Path);
 
  Path2Size = 0;
  Path2     = NULL;
 
  if ((FileList == NULL) || (*FileList == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  if ((*Path == L'.') && (*(Path+1) == L'\\')) {
    Path += 2;
  }
 
  //
  // convert a local path to an absolute path
  //
  if (StrStr (Path, L":") == NULL) {
    CurDir = EfiShellGetCurDir (NULL);
    if (CurDir == NULL) {
      return EFI_NOT_FOUND;
    }
 
    ASSERT ((Path2 == NULL && Path2Size == 0) || (Path2 != NULL));
    StrnCatGrow (&Path2, &Path2Size, CurDir, 0);
    StrnCatGrow (&Path2, &Path2Size, L"\\", 0);
    if (*Path == L'\\') {
      Path++;
      while (PathRemoveLastItem (Path2)) {
      }
    }
 
    ASSERT ((Path2 == NULL && Path2Size == 0) || (Path2 != NULL));
    StrnCatGrow (&Path2, &Path2Size, Path, 0);
  } else {
    ASSERT (Path2 == NULL);
    StrnCatGrow (&Path2, NULL, Path, 0);
  }
 
  PathCleanUpDirectories (Path2);
 
  //
  // do the search
  //
  Status = EfiShellFindFiles (Path2, FileList);
 
  FreePool (Path2);
 
  if (EFI_ERROR (Status)) {
    return (Status);
  }
 
  Found = FALSE;
  //
  // We had no errors so open all the files (that are not already opened...)
  //
  for ( ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetFirstNode (&(*FileList)->Link)
        ; !IsNull (&(*FileList)->Link, &ShellFileListItem->Link)
        ; ShellFileListItem = (EFI_SHELL_FILE_INFO *)GetNextNode (&(*FileList)->Link, &ShellFileListItem->Link)
        )
  {
    if ((ShellFileListItem->Status == 0) && (ShellFileListItem->Handle == NULL)) {
      ShellFileListItem->Status = EfiShellOpenFileByName (ShellFileListItem->FullName, &ShellFileListItem->Handle, OpenMode);
      Found                     = TRUE;
    }
  }
 
  if (!Found) {
    return (EFI_NOT_FOUND);
  }
 
  return (EFI_SUCCESS);
}
 
CONST CHAR16 *
EFIAPI
EfiShellGetEnvEx (
  IN  CONST CHAR16  *Name,
  OUT       UINT32  *Attributes OPTIONAL
  )
{
  EFI_STATUS    Status;
  VOID          *Buffer;
  UINTN         Size;
  ENV_VAR_LIST  *Node;
  CHAR16        *CurrentWriteLocation;
 
  Size   = 0;
  Buffer = NULL;
 
  if (Name == NULL) {
    //
    // Build the semi-colon delimited list. (2 passes)
    //
    for ( Node = (ENV_VAR_LIST *)GetFirstNode (&gShellEnvVarList.Link)
          ; !IsNull (&gShellEnvVarList.Link, &Node->Link)
          ; Node = (ENV_VAR_LIST *)GetNextNode (&gShellEnvVarList.Link, &Node->Link)
          )
    {
      ASSERT (Node->Key != NULL);
      Size += StrSize (Node->Key);
    }
 
    Size += 2*sizeof (CHAR16);
 
    Buffer = AllocateZeroPool (Size);
    if (Buffer == NULL) {
      return (NULL);
    }
 
    CurrentWriteLocation = (CHAR16 *)Buffer;
 
    for ( Node = (ENV_VAR_LIST *)GetFirstNode (&gShellEnvVarList.Link)
          ; !IsNull (&gShellEnvVarList.Link, &Node->Link)
          ; Node = (ENV_VAR_LIST *)GetNextNode (&gShellEnvVarList.Link, &Node->Link)
          )
    {
      ASSERT (Node->Key != NULL);
      StrCpyS (
        CurrentWriteLocation,
        (Size)/sizeof (CHAR16) - (CurrentWriteLocation - ((CHAR16 *)Buffer)),
        Node->Key
        );
      CurrentWriteLocation += StrLen (CurrentWriteLocation) + 1;
    }
  } else {
    //
    // We are doing a specific environment variable
    //
    Status = ShellFindEnvVarInList (Name, (CHAR16 **)&Buffer, &Size, Attributes);
 
    if (EFI_ERROR (Status)) {
      //
      // get the size we need for this EnvVariable
      //
      Status = SHELL_GET_ENVIRONMENT_VARIABLE_AND_ATTRIBUTES (Name, Attributes, &Size, Buffer);
      if (Status == EFI_BUFFER_TOO_SMALL) {
        //
        // Allocate the space and recall the get function
        //
        Buffer = AllocateZeroPool (Size);
        if (Buffer == NULL) {
          return NULL;
        }
 
        Status = SHELL_GET_ENVIRONMENT_VARIABLE_AND_ATTRIBUTES (Name, Attributes, &Size, Buffer);
      }
 
      //
      // we didn't get it (might not exist)
      // free the memory if we allocated any and return NULL
      //
      if (EFI_ERROR (Status)) {
        if (Buffer != NULL) {
          FreePool (Buffer);
        }
 
        return (NULL);
      } else {
        //
        // If we did not find the environment variable in the gShellEnvVarList
        // but get it from UEFI variable storage successfully then we need update
        // the gShellEnvVarList.
        //
        ShellFreeEnvVarList ();
        Status = ShellInitEnvVarList ();
        ASSERT (Status == EFI_SUCCESS);
      }
    }
  }
 
  //
  // return the buffer
  //
  return (AddBufferToFreeList (Buffer));
}
 
CONST CHAR16 *
EFIAPI
EfiShellGetEnv (
  IN CONST CHAR16  *Name
  )
{
  return (EfiShellGetEnvEx (Name, NULL));
}
 
EFI_STATUS
InternalEfiShellSetEnv (
  IN CONST CHAR16  *Name,
  IN CONST CHAR16  *Value,
  IN BOOLEAN       Volatile
  )
{
  EFI_STATUS  Status;
 
  if ((Value == NULL) || (StrLen (Value) == 0)) {
    Status = SHELL_DELETE_ENVIRONMENT_VARIABLE (Name);
    if (!EFI_ERROR (Status)) {
      ShellRemvoeEnvVarFromList (Name);
    }
  } else {
    SHELL_DELETE_ENVIRONMENT_VARIABLE (Name);
    Status = ShellAddEnvVarToList (
               Name,
               Value,
               StrSize (Value),
               EFI_VARIABLE_BOOTSERVICE_ACCESS | (Volatile ? 0 : EFI_VARIABLE_NON_VOLATILE)
               );
    if (!EFI_ERROR (Status)) {
      Status = Volatile
             ? SHELL_SET_ENVIRONMENT_VARIABLE_V (Name, StrSize (Value) - sizeof (CHAR16), Value)
             : SHELL_SET_ENVIRONMENT_VARIABLE_NV (Name, StrSize (Value) - sizeof (CHAR16), Value);
      if (EFI_ERROR (Status)) {
        ShellRemvoeEnvVarFromList (Name);
      }
    }
  }
 
  return Status;
}
 
EFI_STATUS
EFIAPI
EfiShellSetEnv (
  IN CONST CHAR16  *Name,
  IN CONST CHAR16  *Value,
  IN BOOLEAN       Volatile
  )
{
  if ((Name == NULL) || (*Name == CHAR_NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  //
  // Make sure we dont 'set' a predefined read only variable
  //
  if ((StrCmp (Name, L"cwd") == 0) ||
      (StrCmp (Name, L"lasterror") == 0) ||
      (StrCmp (Name, L"profiles") == 0) ||
      (StrCmp (Name, L"uefishellsupport") == 0) ||
      (StrCmp (Name, L"uefishellversion") == 0) ||
      (StrCmp (Name, L"uefiversion") == 0) ||
      (!ShellInfoObject.ShellInitSettings.BitUnion.Bits.NoNest &&
       (StrCmp (Name, mNoNestingEnvVarName) == 0))
      )
  {
    return (EFI_INVALID_PARAMETER);
  }
 
  return (InternalEfiShellSetEnv (Name, Value, Volatile));
}
 
CONST CHAR16 *
EFIAPI
EfiShellGetCurDir (
  IN CONST CHAR16  *FileSystemMapping OPTIONAL
  )
{
  CHAR16          *PathToReturn;
  UINTN           Size;
  SHELL_MAP_LIST  *MapListItem;
 
  if (!IsListEmpty (&gShellMapList.Link)) {
    //
    // if parameter is NULL, use current
    //
    if (FileSystemMapping == NULL) {
      return (EfiShellGetEnv (L"cwd"));
    } else {
      Size         = 0;
      PathToReturn = NULL;
      MapListItem  = ShellCommandFindMapItem (FileSystemMapping);
      if (MapListItem != NULL) {
        ASSERT ((PathToReturn == NULL && Size == 0) || (PathToReturn != NULL));
        PathToReturn = StrnCatGrow (&PathToReturn, &Size, MapListItem->MapName, 0);
        PathToReturn = StrnCatGrow (&PathToReturn, &Size, MapListItem->CurrentDirectoryPath, 0);
      }
    }
 
    return (AddBufferToFreeList (PathToReturn));
  } else {
    return (NULL);
  }
}
 
EFI_STATUS
EFIAPI
EfiShellSetCurDir (
  IN CONST CHAR16  *FileSystem OPTIONAL,
  IN CONST CHAR16  *Dir
  )
{
  CHAR16          *MapName;
  SHELL_MAP_LIST  *MapListItem;
  UINTN           Size;
  EFI_STATUS      Status;
  CHAR16          *TempString;
  CHAR16          *DirectoryName;
  UINTN           TempLen;
 
  Size          = 0;
  MapName       = NULL;
  MapListItem   = NULL;
  TempString    = NULL;
  DirectoryName = NULL;
 
  if (((FileSystem == NULL) && (Dir == NULL)) || (Dir == NULL)) {
    return (EFI_INVALID_PARAMETER);
  }
 
  if (IsListEmpty (&gShellMapList.Link)) {
    return (EFI_NOT_FOUND);
  }
 
  DirectoryName = StrnCatGrow (&DirectoryName, NULL, Dir, 0);
  if (DirectoryName == NULL) {
    ASSERT (DirectoryName != NULL);
    return (EFI_OUT_OF_RESOURCES);
  }
 
  PathCleanUpDirectories (DirectoryName);
 
  if (FileSystem == NULL) {
    //
    // determine the file system mapping to use
    //
    if (StrStr (DirectoryName, L":") != NULL) {
      ASSERT (MapName == NULL);
      MapName = StrnCatGrow (&MapName, NULL, DirectoryName, (StrStr (DirectoryName, L":")-DirectoryName+1));
    }
 
    //
    // find the file system mapping's entry in the list
    // or use current
    //
    if (MapName != NULL) {
      MapListItem = ShellCommandFindMapItem (MapName);
 
      //
      // make that the current file system mapping
      //
      if (MapListItem != NULL) {
        gShellCurMapping = MapListItem;
      }
    } else {
      MapListItem = gShellCurMapping;
    }
 
    if (MapListItem == NULL) {
      FreePool (DirectoryName);
      SHELL_FREE_NON_NULL (MapName);
      return (EFI_NOT_FOUND);
    }
 
    //
    // now update the MapListItem's current directory
    //
    if ((MapListItem->CurrentDirectoryPath != NULL) && (DirectoryName[StrLen (DirectoryName) - 1] != L':')) {
      FreePool (MapListItem->CurrentDirectoryPath);
      MapListItem->CurrentDirectoryPath = NULL;
    }
 
    if (MapName != NULL) {
      TempLen = StrLen (MapName);
      if (TempLen != StrLen (DirectoryName)) {
        ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
        MapListItem->CurrentDirectoryPath = StrnCatGrow (&MapListItem->CurrentDirectoryPath, &Size, DirectoryName+StrLen (MapName), 0);
      }
 
      FreePool (MapName);
    } else {
      ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
      MapListItem->CurrentDirectoryPath = StrnCatGrow (&MapListItem->CurrentDirectoryPath, &Size, DirectoryName, 0);
    }
 
    if (((MapListItem->CurrentDirectoryPath != NULL) && (MapListItem->CurrentDirectoryPath[StrLen (MapListItem->CurrentDirectoryPath)-1] == L'\\')) || (MapListItem->CurrentDirectoryPath == NULL)) {
      ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
      if (MapListItem->CurrentDirectoryPath != NULL) {
        MapListItem->CurrentDirectoryPath[StrLen (MapListItem->CurrentDirectoryPath)-1] = CHAR_NULL;
      }
    }
  } else {
    //
    // cant have a mapping in the directory...
    //
    if (StrStr (DirectoryName, L":") != NULL) {
      FreePool (DirectoryName);
      return (EFI_INVALID_PARAMETER);
    }
 
    //
    // FileSystem != NULL
    //
    MapListItem = ShellCommandFindMapItem (FileSystem);
    if (MapListItem == NULL) {
      FreePool (DirectoryName);
      return (EFI_INVALID_PARAMETER);
    }
 
    //    gShellCurMapping = MapListItem;
    if (DirectoryName != NULL) {
      //
      // change current dir on that file system
      //
 
      if (MapListItem->CurrentDirectoryPath != NULL) {
        FreePool (MapListItem->CurrentDirectoryPath);
        DEBUG_CODE (
          MapListItem->CurrentDirectoryPath = NULL;
          );
      }
 
      //      ASSERT((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
      //      MapListItem->CurrentDirectoryPath = StrnCatGrow(&MapListItem->CurrentDirectoryPath, &Size, FileSystem, 0);
      ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
      MapListItem->CurrentDirectoryPath = StrnCatGrow (&MapListItem->CurrentDirectoryPath, &Size, L"\\", 0);
      ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
      MapListItem->CurrentDirectoryPath = StrnCatGrow (&MapListItem->CurrentDirectoryPath, &Size, DirectoryName, 0);
      if ((MapListItem->CurrentDirectoryPath != NULL) && (MapListItem->CurrentDirectoryPath[StrLen (MapListItem->CurrentDirectoryPath)-1] == L'\\')) {
        ASSERT ((MapListItem->CurrentDirectoryPath == NULL && Size == 0) || (MapListItem->CurrentDirectoryPath != NULL));
        MapListItem->CurrentDirectoryPath[StrLen (MapListItem->CurrentDirectoryPath)-1] = CHAR_NULL;
      }
    }
  }
 
  FreePool (DirectoryName);
  //
  // if updated the current directory then update the environment variable
  //
  if (MapListItem == gShellCurMapping) {
    Size = 0;
    ASSERT ((TempString == NULL && Size == 0) || (TempString != NULL));
    StrnCatGrow (&TempString, &Size, MapListItem->MapName, 0);
    ASSERT ((TempString == NULL && Size == 0) || (TempString != NULL));
    StrnCatGrow (&TempString, &Size, MapListItem->CurrentDirectoryPath, 0);
    Status =  InternalEfiShellSetEnv (L"cwd", TempString, TRUE);
    FreePool (TempString);
    return (Status);
  }
 
  return (EFI_SUCCESS);
}
 
EFI_STATUS
EFIAPI
EfiShellGetHelpText (
  IN CONST CHAR16  *Command,
  IN CONST CHAR16  *Sections OPTIONAL,
  OUT CHAR16       **HelpText
  )
{
  CONST CHAR16  *ManFileName;
  CHAR16        *FixCommand;
  EFI_STATUS    Status;
 
  ASSERT (HelpText != NULL);
  FixCommand = NULL;
 
  ManFileName = ShellCommandGetManFileNameHandler (Command);
 
  if (ManFileName != NULL) {
    return (ProcessManFile (ManFileName, Command, Sections, NULL, HelpText));
  } else {
    if (  (StrLen (Command) > 4)
       && ((Command[StrLen (Command)-1] == L'i') || (Command[StrLen (Command)-1] == L'I'))
       && ((Command[StrLen (Command)-2] == L'f') || (Command[StrLen (Command)-2] == L'F'))
       && ((Command[StrLen (Command)-3] == L'e') || (Command[StrLen (Command)-3] == L'E'))
       && (Command[StrLen (Command)-4] == L'.')
          )
    {
      FixCommand = AllocateZeroPool (StrSize (Command) - 4 * sizeof (CHAR16));
      if (FixCommand == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }
 
      StrnCpyS (
        FixCommand,
        (StrSize (Command) - 4 * sizeof (CHAR16))/sizeof (CHAR16),
        Command,
        StrLen (Command)-4
        );
      Status = ProcessManFile (FixCommand, FixCommand, Sections, NULL, HelpText);
      FreePool (FixCommand);
      return Status;
    } else {
      return (ProcessManFile (Command, Command, Sections, NULL, HelpText));
    }
  }
}
 
BOOLEAN
EFIAPI
EfiShellGetPageBreak (
  VOID
  )
{
  return (ShellInfoObject.PageBreakEnabled);
}
 
BOOLEAN
EFIAPI
EfiShellIsRootShell (
  VOID
  )
{
  return (ShellInfoObject.RootShellInstance);
}
 
CHAR16 *
InternalEfiShellGetListAlias (
  VOID
  )
{
  EFI_STATUS  Status;
  EFI_GUID    Guid;
  CHAR16      *VariableName;
  UINTN       NameSize;
  UINTN       NameBufferSize;
  CHAR16      *RetVal;
  UINTN       RetSize;
 
  NameBufferSize = INIT_NAME_BUFFER_SIZE;
  VariableName   = AllocateZeroPool (NameBufferSize);
  RetSize        = 0;
  RetVal         = NULL;
 
  if (VariableName == NULL) {
    return (NULL);
  }
 
  VariableName[0] = CHAR_NULL;
 
  while (TRUE) {
    NameSize = NameBufferSize;
    Status   = gRT->GetNextVariableName (&NameSize, VariableName, &Guid);
    if (Status == EFI_NOT_FOUND) {
      break;
    } else if (Status == EFI_BUFFER_TOO_SMALL) {
      NameBufferSize = NameSize > NameBufferSize * 2 ? NameSize : NameBufferSize * 2;
      SHELL_FREE_NON_NULL (VariableName);
      VariableName = AllocateZeroPool (NameBufferSize);
      if (VariableName == NULL) {
        Status = EFI_OUT_OF_RESOURCES;
        SHELL_FREE_NON_NULL (RetVal);
        RetVal = NULL;
        break;
      }
 
      NameSize = NameBufferSize;
      Status   = gRT->GetNextVariableName (&NameSize, VariableName, &Guid);
    }
 
    if (EFI_ERROR (Status)) {
      SHELL_FREE_NON_NULL (RetVal);
      RetVal = NULL;
      break;
    }
 
    if (CompareGuid (&Guid, &gShellAliasGuid)) {
      ASSERT ((RetVal == NULL && RetSize == 0) || (RetVal != NULL));
      RetVal = StrnCatGrow (&RetVal, &RetSize, VariableName, 0);
      RetVal = StrnCatGrow (&RetVal, &RetSize, L";", 0);
    } // compare guid
  } // while
 
  SHELL_FREE_NON_NULL (VariableName);
 
  return (RetVal);
}
 
CHAR16 *
ToLower (
  CHAR16  *Str
  )
{
  UINTN  Index;
 
  for (Index = 0; Str[Index] != L'\0'; Index++) {
    if ((Str[Index] >= L'A') && (Str[Index] <= L'Z')) {
      Str[Index] -= (CHAR16)(L'A' - L'a');
    }
  }
 
  return Str;
}
 
CONST CHAR16 *
EFIAPI
EfiShellGetAlias (
  IN  CONST CHAR16  *Alias,
  OUT BOOLEAN       *Volatile OPTIONAL
  )
{
  CHAR16      *RetVal;
  UINTN       RetSize;
  UINT32      Attribs;
  EFI_STATUS  Status;
  CHAR16      *AliasLower;
  CHAR16      *AliasVal;
 
  // Convert to lowercase to make aliases case-insensitive
  if (Alias != NULL) {
    AliasLower = AllocateCopyPool (StrSize (Alias), Alias);
    if (AliasLower == NULL) {
      return NULL;
    }
 
    ToLower (AliasLower);
 
    if (Volatile == NULL) {
      GetVariable2 (AliasLower, &gShellAliasGuid, (VOID **)&AliasVal, NULL);
      FreePool (AliasLower);
      return (AddBufferToFreeList (AliasVal));
    }
 
    RetSize = 0;
    RetVal  = NULL;
    Status  = gRT->GetVariable (AliasLower, &gShellAliasGuid, &Attribs, &RetSize, RetVal);
    if (Status == EFI_BUFFER_TOO_SMALL) {
      RetVal = AllocateZeroPool (RetSize);
      if (RetVal == NULL) {
        FreePool (AliasLower);
        return NULL;
      }
 
      Status = gRT->GetVariable (AliasLower, &gShellAliasGuid, &Attribs, &RetSize, RetVal);
    }
 
    if (EFI_ERROR (Status)) {
      if (RetVal != NULL) {
        FreePool (RetVal);
      }
 
      FreePool (AliasLower);
      return (NULL);
    }
 
    if ((EFI_VARIABLE_NON_VOLATILE & Attribs) == EFI_VARIABLE_NON_VOLATILE) {
      *Volatile = FALSE;
    } else {
      *Volatile = TRUE;
    }
 
    FreePool (AliasLower);
    return (AddBufferToFreeList (RetVal));
  }
 
  return (AddBufferToFreeList (InternalEfiShellGetListAlias ()));
}
 
EFI_STATUS
InternalSetAlias (
  IN CONST CHAR16  *Command,
  IN CONST CHAR16  *Alias,
  IN BOOLEAN       Volatile
  )
{
  EFI_STATUS  Status;
  CHAR16      *AliasLower;
  BOOLEAN     DeleteAlias;
 
  DeleteAlias = FALSE;
  if (Alias == NULL) {
    //
    // We must be trying to remove one if Alias is NULL
    // remove an alias (but passed in COMMAND parameter)
    //
    Alias       = Command;
    DeleteAlias = TRUE;
  }
 
  ASSERT (Alias != NULL);
 
  //
  // Convert to lowercase to make aliases case-insensitive
  //
  AliasLower = AllocateCopyPool (StrSize (Alias), Alias);
  if (AliasLower == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  ToLower (AliasLower);
 
  if (DeleteAlias) {
    Status = gRT->SetVariable (AliasLower, &gShellAliasGuid, 0, 0, NULL);
  } else {
    Status = gRT->SetVariable (
                    AliasLower,
                    &gShellAliasGuid,
                    EFI_VARIABLE_BOOTSERVICE_ACCESS | (Volatile ? 0 : EFI_VARIABLE_NON_VOLATILE),
                    StrSize (Command),
                    (VOID *)Command
                    );
  }
 
  FreePool (AliasLower);
 
  return Status;
}
 
EFI_STATUS
EFIAPI
EfiShellSetAlias (
  IN CONST CHAR16  *Command,
  IN CONST CHAR16  *Alias,
  IN BOOLEAN       Replace,
  IN BOOLEAN       Volatile
  )
{
  if (ShellCommandIsOnAliasList ((Alias == NULL) ? Command : Alias)) {
    //
    // cant set over a built in alias
    //
    return (EFI_ACCESS_DENIED);
  } else if ((Command == NULL) || (*Command == CHAR_NULL) || (StrLen (Command) == 0)) {
    //
    // Command is null or empty
    //
    return (EFI_INVALID_PARAMETER);
  } else if ((EfiShellGetAlias (Command, NULL) != NULL) && !Replace) {
    //
    // Alias already exists, Replace not set
    //
    return (EFI_ACCESS_DENIED);
  } else {
    return (InternalSetAlias (Command, Alias, Volatile));
  }
}
 
// Pure FILE_HANDLE operations are passed to FileHandleLib
// these functions are indicated by the *
EFI_SHELL_PROTOCOL  mShellProtocol = {
  EfiShellExecute,
  EfiShellGetEnv,
  EfiShellSetEnv,
  EfiShellGetAlias,
  EfiShellSetAlias,
  EfiShellGetHelpText,
  EfiShellGetDevicePathFromMap,
  EfiShellGetMapFromDevicePath,
  EfiShellGetDevicePathFromFilePath,
  EfiShellGetFilePathFromDevicePath,
  EfiShellSetMap,
  EfiShellGetCurDir,
  EfiShellSetCurDir,
  EfiShellOpenFileList,
  EfiShellFreeFileList,
  EfiShellRemoveDupInFileList,
  EfiShellBatchIsActive,
  EfiShellIsRootShell,
  EfiShellEnablePageBreak,
  EfiShellDisablePageBreak,
  EfiShellGetPageBreak,
  EfiShellGetDeviceName,
  (EFI_SHELL_GET_FILE_INFO)FileHandleGetInfo,         // *
  (EFI_SHELL_SET_FILE_INFO)FileHandleSetInfo,         // *
  EfiShellOpenFileByName,
  EfiShellClose,
  EfiShellCreateFile,
  (EFI_SHELL_READ_FILE)FileHandleRead,                // *
  (EFI_SHELL_WRITE_FILE)FileHandleWrite,              // *
  (EFI_SHELL_DELETE_FILE)FileHandleDelete,            // *
  EfiShellDeleteFileByName,
  (EFI_SHELL_GET_FILE_POSITION)FileHandleGetPosition, // *
  (EFI_SHELL_SET_FILE_POSITION)FileHandleSetPosition, // *
  (EFI_SHELL_FLUSH_FILE)FileHandleFlush,              // *
  EfiShellFindFiles,
  EfiShellFindFilesInDir,
  (EFI_SHELL_GET_FILE_SIZE)FileHandleGetSize,         // *
  EfiShellOpenRoot,
  EfiShellOpenRootByHandle,
  NULL,
  SHELL_MAJOR_VERSION,
  SHELL_MINOR_VERSION,
 
  // New for UEFI Shell 2.1
  EfiShellRegisterGuidName,
  EfiShellGetGuidName,
  EfiShellGetGuidFromName,
  EfiShellGetEnvEx
};
 
EFI_STATUS
CreatePopulateInstallShellProtocol (
  IN OUT EFI_SHELL_PROTOCOL  **NewShell
  )
{
  EFI_STATUS                  Status;
  UINTN                       BufferSize;
  EFI_HANDLE                  *Buffer;
  UINTN                       HandleCounter;
  SHELL_PROTOCOL_HANDLE_LIST  *OldProtocolNode;
  EFI_SHELL_PROTOCOL          *OldShell;
 
  if (NewShell == NULL) {
    return (EFI_INVALID_PARAMETER);
  }
 
  BufferSize      = 0;
  Buffer          = NULL;
  OldProtocolNode = NULL;
  InitializeListHead (&ShellInfoObject.OldShellList.Link);
 
  //
  // Initialize EfiShellProtocol object...
  //
  Status = gBS->CreateEvent (
                  0,
                  0,
                  NULL,
                  NULL,
                  &mShellProtocol.ExecutionBreak
                  );
  if (EFI_ERROR (Status)) {
    return (Status);
  }
 
  //
  // Get the size of the buffer we need.
  //
  Status = gBS->LocateHandle (
                  ByProtocol,
                  &gEfiShellProtocolGuid,
                  NULL,
                  &BufferSize,
                  Buffer
                  );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    //
    // Allocate and recall with buffer of correct size
    //
    Buffer = AllocateZeroPool (BufferSize);
    if (Buffer == NULL) {
      return (EFI_OUT_OF_RESOURCES);
    }
 
    Status = gBS->LocateHandle (
                    ByProtocol,
                    &gEfiShellProtocolGuid,
                    NULL,
                    &BufferSize,
                    Buffer
                    );
    if (EFI_ERROR (Status)) {
      FreePool (Buffer);
      return (Status);
    }
 
    //
    // now overwrite each of them, but save the info to restore when we end.
    //
    for (HandleCounter = 0; HandleCounter < (BufferSize/sizeof (EFI_HANDLE)); HandleCounter++) {
      Status = gBS->OpenProtocol (
                      Buffer[HandleCounter],
                      &gEfiShellProtocolGuid,
                      (VOID **)&OldShell,
                      gImageHandle,
                      NULL,
                      EFI_OPEN_PROTOCOL_GET_PROTOCOL
                      );
      if (!EFI_ERROR (Status)) {
        OldProtocolNode = AllocateZeroPool (sizeof (SHELL_PROTOCOL_HANDLE_LIST));
        if (OldProtocolNode == NULL) {
          if (!IsListEmpty (&ShellInfoObject.OldShellList.Link)) {
            CleanUpShellProtocol (&mShellProtocol);
          }
 
          Status = EFI_OUT_OF_RESOURCES;
          break;
        }
 
        //
        // reinstall over the old one...
        //
        OldProtocolNode->Handle    = Buffer[HandleCounter];
        OldProtocolNode->Interface = OldShell;
        Status                     = gBS->ReinstallProtocolInterface (
                                            OldProtocolNode->Handle,
                                            &gEfiShellProtocolGuid,
                                            OldProtocolNode->Interface,
                                            (VOID *)(&mShellProtocol)
                                            );
        if (!EFI_ERROR (Status)) {
          //
          // we reinstalled successfully.  log this so we can reverse it later.
          //
 
          //
          // add to the list for subsequent...
          //
          InsertTailList (&ShellInfoObject.OldShellList.Link, &OldProtocolNode->Link);
        }
      }
    }
 
    FreePool (Buffer);
  } else if (Status == EFI_NOT_FOUND) {
    ASSERT (IsListEmpty (&ShellInfoObject.OldShellList.Link));
    //
    // no one else published yet.  just publish it ourselves.
    //
    Status = gBS->InstallProtocolInterface (
                    &gImageHandle,
                    &gEfiShellProtocolGuid,
                    EFI_NATIVE_INTERFACE,
                    (VOID *)(&mShellProtocol)
                    );
  }
 
  if (PcdGetBool (PcdShellSupportOldProtocols)) {
  }
 
  if (!EFI_ERROR (Status)) {
    *NewShell = &mShellProtocol;
  }
 
  return (Status);
}
 
EFI_STATUS
CleanUpShellProtocol (
  IN OUT EFI_SHELL_PROTOCOL  *NewShell
  )
{
  SHELL_PROTOCOL_HANDLE_LIST  *Node2;
 
  //
  // if we need to restore old protocols...
  //
  if (!IsListEmpty (&ShellInfoObject.OldShellList.Link)) {
    for (Node2 = (SHELL_PROTOCOL_HANDLE_LIST *)GetFirstNode (&ShellInfoObject.OldShellList.Link)
         ; !IsListEmpty (&ShellInfoObject.OldShellList.Link)
         ; Node2 = (SHELL_PROTOCOL_HANDLE_LIST *)GetFirstNode (&ShellInfoObject.OldShellList.Link)
         )
    {
      RemoveEntryList (&Node2->Link);
      gBS->ReinstallProtocolInterface (Node2->Handle, &gEfiShellProtocolGuid, NewShell, Node2->Interface);
      FreePool (Node2);
    }
  } else {
    //
    // no need to restore
    //
    gBS->UninstallProtocolInterface (gImageHandle, &gEfiShellProtocolGuid, NewShell);
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
CleanUpShellEnvironment (
  IN OUT EFI_SHELL_PROTOCOL  *NewShell
  )
{
  EFI_STATUS                         Status;
  EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *SimpleEx;
 
  CleanUpShellProtocol (NewShell);
 
  Status                   = gBS->CloseEvent (NewShell->ExecutionBreak);
  NewShell->ExecutionBreak = NULL;
 
  Status = gBS->OpenProtocol (
                  gST->ConsoleInHandle,
                  &gEfiSimpleTextInputExProtocolGuid,
                  (VOID **)&SimpleEx,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
 
  if (!EFI_ERROR (Status)) {
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlCNotifyHandle1);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlCNotifyHandle2);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlCNotifyHandle3);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlCNotifyHandle4);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlSNotifyHandle1);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlSNotifyHandle2);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlSNotifyHandle3);
    Status = SimpleEx->UnregisterKeyNotify (SimpleEx, ShellInfoObject.CtrlSNotifyHandle4);
  }
 
  return (Status);
}
 
EFI_STATUS
EFIAPI
NotificationFunction (
  IN EFI_KEY_DATA  *KeyData
  )
{
  if (((KeyData->Key.UnicodeChar == L'c') &&
       ((KeyData->KeyState.KeyShiftState == (EFI_SHIFT_STATE_VALID|EFI_LEFT_CONTROL_PRESSED)) || (KeyData->KeyState.KeyShiftState  == (EFI_SHIFT_STATE_VALID|EFI_RIGHT_CONTROL_PRESSED)))) ||
      (KeyData->Key.UnicodeChar == 3)
      )
  {
    if (ShellInfoObject.NewEfiShellProtocol->ExecutionBreak == NULL) {
      return (EFI_UNSUPPORTED);
    }
 
    return (gBS->SignalEvent (ShellInfoObject.NewEfiShellProtocol->ExecutionBreak));
  } else if ((KeyData->Key.UnicodeChar == L's') &&
             ((KeyData->KeyState.KeyShiftState  == (EFI_SHIFT_STATE_VALID|EFI_LEFT_CONTROL_PRESSED)) || (KeyData->KeyState.KeyShiftState  == (EFI_SHIFT_STATE_VALID|EFI_RIGHT_CONTROL_PRESSED)))
             )
  {
    ShellInfoObject.HaltOutput = TRUE;
  }
 
  return (EFI_SUCCESS);
}
 
EFI_STATUS
InernalEfiShellStartMonitor (
  VOID
  )
{
  EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *SimpleEx;
  EFI_KEY_DATA                       KeyData;
  EFI_STATUS                         Status;
 
  Status = gBS->OpenProtocol (
                  gST->ConsoleInHandle,
                  &gEfiSimpleTextInputExProtocolGuid,
                  (VOID **)&SimpleEx,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    ShellPrintHiiEx (
      -1,
      -1,
      NULL,
      STRING_TOKEN (STR_SHELL_NO_IN_EX),
      ShellInfoObject.HiiHandle
      );
    return (EFI_SUCCESS);
  }
 
  if (ShellInfoObject.NewEfiShellProtocol->ExecutionBreak == NULL) {
    return (EFI_UNSUPPORTED);
  }
 
  KeyData.KeyState.KeyToggleState = 0;
  KeyData.Key.ScanCode            = 0;
  KeyData.KeyState.KeyShiftState  = EFI_SHIFT_STATE_VALID|EFI_LEFT_CONTROL_PRESSED;
  KeyData.Key.UnicodeChar         = L'c';
 
  Status = SimpleEx->RegisterKeyNotify (
                       SimpleEx,
                       &KeyData,
                       NotificationFunction,
                       &ShellInfoObject.CtrlCNotifyHandle1
                       );
 
  KeyData.KeyState.KeyShiftState = EFI_SHIFT_STATE_VALID|EFI_RIGHT_CONTROL_PRESSED;
  if (!EFI_ERROR (Status)) {
    Status = SimpleEx->RegisterKeyNotify (
                         SimpleEx,
                         &KeyData,
                         NotificationFunction,
                         &ShellInfoObject.CtrlCNotifyHandle2
                         );
  }
 
  KeyData.KeyState.KeyShiftState = EFI_SHIFT_STATE_VALID|EFI_LEFT_CONTROL_PRESSED;
  KeyData.Key.UnicodeChar        = 3;
  if (!EFI_ERROR (Status)) {
    Status = SimpleEx->RegisterKeyNotify (
                         SimpleEx,
                         &KeyData,
                         NotificationFunction,
                         &ShellInfoObject.CtrlCNotifyHandle3
                         );
  }
 
  KeyData.KeyState.KeyShiftState = EFI_SHIFT_STATE_VALID|EFI_RIGHT_CONTROL_PRESSED;
  if (!EFI_ERROR (Status)) {
    Status = SimpleEx->RegisterKeyNotify (
                         SimpleEx,
                         &KeyData,
                         NotificationFunction,
                         &ShellInfoObject.CtrlCNotifyHandle4
                         );
  }
 
  return (Status);
}