--- /dev/null
+include Makefile.vars
+BUILD_SUBDIRS = $(addprefix build/, $(SUBDIRS))
+
+all: build build/Makefile $(BUILD_SUBDIRS)
+ $(MAKE) -C build
+
+$(BUILD_SUBDIRS):
+ mkdir $@
+build:
+ mkdir $@
+build/Makefile: ../Makefile.build
+ cp $< $@
+
+clean:
+ rm -rf build