diff --git a/BaseTools/Source/Python/AutoGen/AutoGen.py b/BaseTools/Source/Python/AutoGen/AutoGen.py
index 1787decd1d..e2589cfbae 100644
--- a/BaseTools/Source/Python/AutoGen/AutoGen.py
+++ b/BaseTools/Source/Python/AutoGen/AutoGen.py
@@ -2421,7 +2421,7 @@ class PlatformAutoGen(AutoGen):
             ToPcd.validlists = FromPcd.validlists
             ToPcd.expressions = FromPcd.expressions
 
-        if ToPcd.DatumType == "VOID*" and ToPcd.MaxDatumSize in ['', None]:
+        if FromPcd != None and ToPcd.DatumType == "VOID*" and ToPcd.MaxDatumSize in ['', None]:
             EdkLogger.debug(EdkLogger.DEBUG_9, "No MaxDatumSize specified for PCD %s.%s" \
                             % (ToPcd.TokenSpaceGuidCName, TokenCName))
             Value = ToPcd.DefaultValue
@@ -2494,6 +2494,19 @@ class PlatformAutoGen(AutoGen):
                             break
                 if Flag:
                     self._OverridePcd(ToPcd, PlatformModule.Pcds[Key], Module)
+        # use PCD value to calculate the MaxDatumSize when it is not specified
+        for Name, Guid in Pcds:
+            Pcd = Pcds[Name, Guid]
+            if Pcd.DatumType == "VOID*" and Pcd.MaxDatumSize in ['', None]:
+                Value = Pcd.DefaultValue
+                if Value in [None, '']:
+                    Pcd.MaxDatumSize = '1'
+                elif Value[0] == 'L':
+                    Pcd.MaxDatumSize = str((len(Value) - 2) * 2)
+                elif Value[0] == '{':
+                    Pcd.MaxDatumSize = str(len(Value.split(',')))
+                else:
+                    Pcd.MaxDatumSize = str(len(Value) - 1)
         return Pcds.values()
 
     ## Resolve library names to library modules
diff --git a/BaseTools/Source/Python/Workspace/DscBuildData.py b/BaseTools/Source/Python/Workspace/DscBuildData.py
index ea8d1847f7..66402c52b7 100644
--- a/BaseTools/Source/Python/Workspace/DscBuildData.py
+++ b/BaseTools/Source/Python/Workspace/DscBuildData.py
@@ -679,8 +679,9 @@ class DscBuildData(PlatformBuildClassObject):
                 for TokenSpaceGuid, PcdCName, Setting, Dummy1, Dummy2, Dummy3, Dummy4,Dummy5 in RecordList:
                     TokenList = GetSplitValueList(Setting)
                     DefaultValue = TokenList[0]
-                    if len(TokenList) > 1:
-                        MaxDatumSize = TokenList[1]
+                    # the format is PcdName| Value | VOID* | MaxDatumSize
+                    if len(TokenList) > 2:
+                        MaxDatumSize = TokenList[2]
                     else:
                         MaxDatumSize = ''
                     TypeString = self._PCD_TYPE_STRING_[Type]