diff --git a/tools/building.py b/tools/building.py
index d1ff4ffa8..47ad82383 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -20,6 +20,8 @@
 # Change Logs:
 # Date           Author       Notes
 # 2015-01-20     Bernard      Add copyright information
+# 2015-07-25     Bernard      Add LOCAL_CCFLAGS/LOCAL_CPPPATH/LOCAL_CPPDEFINES for
+#                             group definition. 
 #
 
 import os
@@ -112,6 +114,8 @@ def PrepareBuilding(env, root_directory, has_libcpu=False, remove_components = [
 
     # add program path
     env.PrependENVPath('PATH', rtconfig.EXEC_PATH)
+    # add rtconfig.h path
+    env.Append(CPPPATH = [str(Dir('#').abspath)])
 
     # add library build action
     act = SCons.Action.Action(BuildLibInstallAction, 'Install compiled library... $TARGET')
@@ -186,7 +190,7 @@ def PrepareBuilding(env, root_directory, has_libcpu=False, remove_components = [
     AddOption('--target',
                       dest='target',
                       type='string',
-                      help='set target project: mdk/iar/vs/ua')
+                      help='set target project: mdk/mdk4/iar/vs/ua')
 
     #{target_name:(CROSS_TOOL, PLATFORM)}
     tgt_dict = {'mdk':('keil', 'armcc'),
@@ -333,6 +337,24 @@ def MergeGroup(src_group, group):
             src_group['CPPDEFINES'] = src_group['CPPDEFINES'] + group['CPPDEFINES']
         else:
             src_group['CPPDEFINES'] = group['CPPDEFINES']
+
+    # for local CCFLAGS/CPPPATH/CPPDEFINES
+    if group.has_key('LOCAL_CCFLAGS'):
+        if src_group.has_key('LOCAL_CCFLAGS'):
+            src_group['LOCAL_CCFLAGS'] = src_group['LOCAL_CCFLAGS'] + group['LOCAL_CCFLAGS']
+        else:
+            src_group['LOCAL_CCFLAGS'] = group['LOCAL_CCFLAGS']
+    if group.has_key('LOCAL_CPPPATH'):
+        if src_group.has_key('LOCAL_CPPPATH'):
+            src_group['LOCAL_CPPPATH'] = src_group['LOCAL_CPPPATH'] + group['LOCAL_CPPPATH']
+        else:
+            src_group['LOCAL_CPPPATH'] = group['LOCAL_CPPPATH']
+    if group.has_key('LOCAL_CPPDEFINES'):
+        if src_group.has_key('LOCAL_CPPDEFINES'):
+            src_group['LOCAL_CPPDEFINES'] = src_group['LOCAL_CPPDEFINES'] + group['LOCAL_CPPDEFINES']
+        else:
+            src_group['LOCAL_CPPDEFINES'] = group['LOCAL_CPPDEFINES']
+
     if group.has_key('LINKFLAGS'):
         if src_group.has_key('LINKFLAGS'):
             src_group['LINKFLAGS'] = src_group['LINKFLAGS'] + group['LINKFLAGS']
@@ -371,13 +393,13 @@ def DefineGroup(name, src, depend, **parameters):
         group['src'] = src
 
     if group.has_key('CCFLAGS'):
-        Env.Append(CCFLAGS = group['CCFLAGS'])
+        Env.AppendUnique(CCFLAGS = group['CCFLAGS'])
     if group.has_key('CPPPATH'):
-        Env.Append(CPPPATH = group['CPPPATH'])
+        Env.AppendUnique(CPPPATH = group['CPPPATH'])
     if group.has_key('CPPDEFINES'):
-        Env.Append(CPPDEFINES = group['CPPDEFINES'])
+        Env.AppendUnique(CPPDEFINES = group['CPPDEFINES'])
     if group.has_key('LINKFLAGS'):
-        Env.Append(LINKFLAGS = group['LINKFLAGS'])
+        Env.AppendUnique(LINKFLAGS = group['LINKFLAGS'])
 
     # check whether to clean up library
     if GetOption('cleanlib') and os.path.exists(os.path.join(group['path'], GroupLibFullName(name, Env))):
@@ -394,13 +416,15 @@ def DefineGroup(name, src, depend, **parameters):
         else : group['LIBPATH'] = [GetCurrentDir()]
 
     if group.has_key('LIBS'):
-        Env.Append(LIBS = group['LIBS'])
+        Env.AppendUnique(LIBS = group['LIBS'])
     if group.has_key('LIBPATH'):
-        Env.Append(LIBPATH = group['LIBPATH'])
+        Env.AppendUnique(LIBPATH = group['LIBPATH'])
 
+    # check whether to build group library
     if group.has_key('LIBRARY'):
         objs = Env.Library(name, group['src'])
     else:
+        # only add source
         objs = group['src']
 
     # merge group
@@ -456,6 +480,26 @@ def BuildLibInstallAction(target, source, env):
             break
 
 def DoBuilding(target, objects):
+    # remove source files with local flags setting
+    for group in Projects:
+        if group.has_key('LOCAL_CCFLAGS') or group.has_key('LOCAL_CPPPATH') or group.has_key('LOCAL_CPPDEFINES'):
+            for source in group['src']:
+                for obj in objects:
+                    if source.abspath == obj.abspath or (len(obj.sources) > 0 and source.abspath == obj.sources[0].abspath):
+                        objects.remove(obj)
+
+    # re-add the source files to the objects
+    for group in Projects:
+        if group.has_key('LOCAL_CCFLAGS') or group.has_key('LOCAL_CPPPATH') or group.has_key('LOCAL_CPPDEFINES'):
+            CCFLAGS = Env.get('CCFLAGS', '') + group.get('LOCAL_CCFLAGS', '')
+            CPPPATH = Env.get('CPPPATH', ['']) + group.get('LOCAL_CPPPATH', [''])
+            CPPDEFINES = Env.get('CPPDEFINES', ['']) + group.get('LOCAL_CPPDEFINES', [''])
+
+            for source in group['src']:
+                objects += Env.Object(source, CCFLAGS = CCFLAGS,
+                    CPPPATH = CPPPATH,
+                    CPPDEFINES = CPPDEFINES)
+
     program = None
     # check whether special buildlib option
     lib_name = GetOption('buildlib')
@@ -500,7 +544,6 @@ def EndBuilding(target, program = None):
                 else:
                     print 'No template project file found.'
 
-
     if GetOption('target') == 'mdk4':
         from keil import MDK4Project
         MDK4Project('project.uvproj', Projects)