[PATCH 1/2] MdePkg: Minor update to the Data parameter for PEI GetVariable()

[Star Zeng <star.zeng@intel.com>]

PI 1.5 spec has minor update to the Data parameter for PEI
GetVariable(), and no real functional behavior change.

The modifier of Data parameter:
OUT VOID *Data
->
OUT VOID *Data OPTIONAL

The comments of Data parameter:
Data    Points to the buffer which will hold the returned variable value.
->
Data    Points to the buffer which will hold the returned variable value.
        May be NULL with a zero DataSize in order to determine the size of the buffer needed.

The patch is to follow the spec to update the definition.

Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdePkg/Include/Ppi/ReadOnlyVariable2.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/MdePkg/Include/Ppi/ReadOnlyVariable2.h b/MdePkg/Include/Ppi/ReadOnlyVariable2.h
index 6a2cd50136b3..6d8ea603811f 100644
--- a/MdePkg/Include/Ppi/ReadOnlyVariable2.h
+++ b/MdePkg/Include/Ppi/ReadOnlyVariable2.h
@@ -2,7 +2,7 @@
   This file declares Read-only Variable Service2 PPI.
   This ppi permits read-only access to the UEFI variable store during the PEI phase.
 
-Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials are licensed and made available under 
 the terms and conditions of the BSD License that accompanies this distribution.  
 The full text of the license may be found at
@@ -41,9 +41,10 @@ typedef struct _EFI_PEI_READ_ONLY_VARIABLE2_PPI  EFI_PEI_READ_ONLY_VARIABLE2_PPI
   @param  DataSize              On entry, points to the size in bytes of the Data buffer.
                                 On return, points to the size of the data returned in Data.
   @param  Data                  Points to the buffer which will hold the returned variable value.
+                                May be NULL with a zero DataSize in order to determine the size of the buffer needed.
 
   @retval EFI_SUCCESS           The variable was read successfully.
-  @retval EFI_NOT_FOUND         The variable could not be found.
+  @retval EFI_NOT_FOUND         The variable was not found.
   @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the resulting data. 
                                 DataSize is updated with the size required for 
                                 the specified variable.
@@ -59,7 +60,7 @@ EFI_STATUS
   IN CONST  EFI_GUID                        *VariableGuid,
   OUT       UINT32                          *Attributes,
   IN OUT    UINTN                           *DataSize,
-  OUT       VOID                            *Data
+  OUT       VOID                            *Data OPTIONAL
   );
 
 
-- 
2.7.0.windows.1