diff --git a/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c b/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
index 8954a5fd8e..cb56f66078 100644
--- a/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
+++ b/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
@@ -214,14 +214,14 @@ FindVariable (
 
     while ((Variable[Index] != NULL) && (Variable[Index] <= GetEndPointer (VariableStoreHeader[Index]))) {
       if (Variable[Index]->StartId == VARIABLE_DATA && Variable[Index]->State == VAR_ADDED) {
-        if (!(EfiAtRuntime () && !(Variable[Index]->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
+        if (!(EfiAtRuntime () && (Variable[Index]->Attributes & EFI_VARIABLE_RUNTIME_ACCESS == 0))) {
           if (VariableName[0] == 0) {
             PtrTrack->CurrPtr   = Variable[Index];
             PtrTrack->Volatile  = (BOOLEAN) Index;
             return EFI_SUCCESS;
           } else {
             if (CompareGuid (VendorGuid, &Variable[Index]->VendorGuid)) {
-              if (!CompareMem (VariableName, GET_VARIABLE_NAME_PTR (Variable[Index]), Variable[Index]->NameSize)) {
+              if (CompareMem (VariableName, GET_VARIABLE_NAME_PTR (Variable[Index]), Variable[Index]->NameSize) == 0) {
                 PtrTrack->CurrPtr   = Variable[Index];
                 PtrTrack->Volatile  = (BOOLEAN) Index;
                 return EFI_SUCCESS;
@@ -389,7 +389,7 @@ GetNextVariableName (
     // Variable is found
     //
     if (Variable.CurrPtr->StartId == VARIABLE_DATA && Variable.CurrPtr->State == VAR_ADDED) {
-      if (!(EfiAtRuntime () && !(Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
+      if (!(EfiAtRuntime () && (Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS == 0))) {
         VarNameSize = Variable.CurrPtr->NameSize;
         if (VarNameSize <= *VariableNameSize) {
           CopyMem (
@@ -527,7 +527,7 @@ SetVariable (
       //
       // Only variable have NV attribute can be updated/deleted in Runtime
       //
-      if (!(Variable.CurrPtr->Attributes & EFI_VARIABLE_NON_VOLATILE)) {
+      if ((Variable.CurrPtr->Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) {
         Status = EFI_INVALID_PARAMETER;
         goto Done;
       }
@@ -548,7 +548,7 @@ SetVariable (
     // then return to the caller immediately.
     //
     if (Variable.CurrPtr->DataSize == DataSize &&
-        !CompareMem (Data, GetVariableDataPtr (Variable.CurrPtr), DataSize)
+        CompareMem (Data, GetVariableDataPtr (Variable.CurrPtr), DataSize) == 0
           ) {
       Status = EFI_SUCCESS;
       goto Done;
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 6d3967947d..8fbcf129fa 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -38,14 +38,6 @@ VARIABLE_CACHE_ENTRY mVariableCache[] = {
 
 VARIABLE_INFO_ENTRY *gVariableInfo = NULL;
 
-EFI_STATUS
-FtwVariableSpace (
-  IN EFI_PHYSICAL_ADDRESS   VariableBaseAddress,
-  IN UINT8                  *Buffer,
-  IN UINTN                  BufferSize
-  );
-
-
 /**
   Acquires lock only at boot time. Simply returns at runtime.
 
@@ -929,7 +921,7 @@ FindVariable (
       if (Variable[Index]->State == VAR_ADDED || 
           Variable[Index]->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)
          ) {
-        if (!EfiAtRuntime () || (Variable[Index]->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)) {
+        if (!EfiAtRuntime () || (Variable[Index]->Attributes & EFI_VARIABLE_RUNTIME_ACCESS != 0)) {
           if (VariableName[0] == 0) {
             if (Variable[Index]->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
               InDeletedVariable     = Variable[Index];
@@ -947,7 +939,7 @@ FindVariable (
               Point = (VOID *) GetVariableNamePtr (Variable[Index]);
 
               ASSERT (NameSizeOfVariable (Variable[Index]) != 0);
-              if (!CompareMem (VariableName, Point, NameSizeOfVariable (Variable[Index]))) {
+              if (CompareMem (VariableName, Point, NameSizeOfVariable (Variable[Index])) == 0) {
                 if (Variable[Index]->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
                   InDeletedVariable     = Variable[Index];
                   InDeletedStorageIndex = Index;
@@ -1136,7 +1128,7 @@ RuntimeServiceGetNextVariableName (
     // Variable is found
     //
     if (IsValidVariableHeader (Variable.CurrPtr) && Variable.CurrPtr->State == VAR_ADDED) {
-      if (!(EfiAtRuntime () && !(Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
+      if ((EfiAtRuntime () && ((Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) == 0)) == 0) {
         VarNameSize = NameSizeOfVariable (Variable.CurrPtr);
         ASSERT (VarNameSize != 0);
 
@@ -1294,7 +1286,7 @@ RuntimeServiceSetVariable (
       //
       // Only variable have NV attribute can be updated/deleted in Runtime
       //
-      if (!(Variable.CurrPtr->Attributes & EFI_VARIABLE_NON_VOLATILE)) {
+      if ((Variable.CurrPtr->Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) {
         Status = EFI_INVALID_PARAMETER;
         goto Done;      
       }
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
index c508d8bade..ec35a7dfcf 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
@@ -70,4 +70,28 @@ typedef struct {
   VOID        *Data;
 } VARIABLE_CACHE_ENTRY;
 
+/**
+  Writes a buffer to variable storage space, in the working block.
+
+  This function writes a buffer to variable storage space into firmware
+  volume block device. The destination is specified by parameter
+  VariableBase. Fault Tolerant Write protocol is used for writing.
+
+  @param  VariableBase   Base address of variable to write
+  @param  Buffer         Point to the data buffer
+  @param  BufferSize     The number of bytes of the data Buffer
+
+  @retval EFI_SUCCESS    The function completed successfully
+  @retval EFI_NOT_FOUND  Fail to locate Fault Tolerant Write protocol
+  @retval EFI_ABORTED    The function could not complete successfully
+
+**/
+EFI_STATUS
+FtwVariableSpace (
+  IN EFI_PHYSICAL_ADDRESS   VariableBase,
+  IN UINT8                  *Buffer,
+  IN UINTN                  BufferSize
+  );
+
+
 #endif