-# The directory part is taken from first prerequisite, so this
-# works even with external modules
+# Single targets are compatible with:
+# - build whith mixed source and output
+# - build with separate output dir 'make O=...'
+# - external modules
+#
+# target-dir => where to store outputfile
+# build-dir => directory in kernel source tree to use
+
+ifeq ($(KBUILD_EXTMOD),)
+ build-dir = $(patsubst %/,%,$(dir $@))
+ target-dir = $(dir $@)
+else
+ zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
+ build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
+ target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
+endif
+