From ebe34c96f473b9b7389f1f05a29c0bdb3fe36ac3 Mon Sep 17 00:00:00 2001
From: Star Zeng <star.zeng@intel.com>
Date: Sat, 12 Jan 2019 16:31:51 +0800
Subject: [PATCH] MdeModulePkg Variable: Remove CacheOffset in UpdateVariable()

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);

Except for the movement above, the patch also capitalizes the first
character of "update the memory copy of Flash region".

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>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Julien Grall <julien.grall@arm.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 424f92a537..14684b3fed 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.