Index: Makefile
===================================================================
--- Makefile	(revision 55cff8653ccc22fcfafe3f303843836673092890)
+++ Makefile	(revision 2345061691c5c1417df08bacc15157b29fd226b5)
@@ -46,5 +46,10 @@
 
 all:
-	tools/config.py default $(ARCH)
+	tools/config.py default $(NARCH)
+ifdef NARCH
+ ifneq ($(ARCH), $(NARCH))
+	$(MAKE) -C . clean
+ endif
+endif
 	$(MAKE) -C . build