[PATCH V2 06/15] MdeModulePkg Variable: Remove CacheOffset in UpdateVariable()

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

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1323
Merge EmuVariable and Real variable driver.

CacheOffset could be removed in UpdateVariable() after
//
// update the memory copy of Flash region.
//
CopyMem (
  (UINT8 *)mNvVariableCache + CacheOffset,
  (UINT8 *)NextVariable, VarSize
   );

is moved to be before mVariableModuleGlobal->NonVolatileLastVariableOffset
value is updated, like right before

mVariableModuleGlobal->NonVolatileLastVariableOffset +=
  HEADER_ALIGN (VarSize);

This patch prepares for adding emulated variable NV mode
support in VariableRuntimeDxe.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 424f92a53757..4d524db30fec 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -2139,7 +2139,6 @@ UpdateVariable (
   VARIABLE_POINTER_TRACK              *Variable;
   VARIABLE_POINTER_TRACK              NvVariable;
   VARIABLE_STORE_HEADER               *VariableStoreHeader;
-  UINTN                               CacheOffset;
   UINT8                               *BufferForMerge;
   UINTN                               MergedBufSize;
   BOOLEAN                             DataReady;
@@ -2577,7 +2576,6 @@ UpdateVariable (
     //
     // Step 1:
     //
-    CacheOffset = mVariableModuleGlobal->NonVolatileLastVariableOffset;
     Status = UpdateVariableStore (
                &mVariableModuleGlobal->VariableGlobal,
                FALSE,
@@ -2643,6 +2641,11 @@ UpdateVariable (
       goto Done;
     }
 
+    //
+    // update the memory copy of Flash region.
+    //
+    CopyMem ((UINT8 *)mNvVariableCache + mVariableModuleGlobal->NonVolatileLastVariableOffset, (UINT8 *)NextVariable, VarSize);
+
     mVariableModuleGlobal->NonVolatileLastVariableOffset += HEADER_ALIGN (VarSize);
 
     if ((Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) != 0) {
@@ -2653,10 +2656,6 @@ UpdateVariable (
         mVariableModuleGlobal->CommonUserVariableTotalSize += HEADER_ALIGN (VarSize);
       }
     }
-    //
-    // update the memory copy of Flash region.
-    //
-    CopyMem ((UINT8 *)mNvVariableCache + CacheOffset, (UINT8 *)NextVariable, VarSize);
   } else {
     //
     // Create a volatile variable.
-- 
2.7.0.windows.1