+BUILDDIRS=$(DIRS:%=build-%)
+CLEANDIRS=$(DIRS:%=clean-%)
+
+all: $(BUILDDIRS) $(FOOTPRINTS) .gitignore
+$(DIRS): $(BUILDDIRS)
+$(BUILDDIRS):
+ $(MAKE) -C $(@:build-%=%)
+
+$(CLEANDIRS):
+ $(MAKE) -C $(@:clean-%=%) clean
+
+$(FOOTPRINTS): footprint.5c