obj-y := $(addsuffix /, $(dts-dirs))
+dtstree := $(srctree)/$(src)
+dtb-$(CONFIG_OF_ALL_DTBS) := $(patsubst $(dtstree)/%.dts,%.dtb, $(foreach d,$(dts-dirs), $(wildcard $(dtstree)/$(d)/*.dts)))
+
always := $(dtb-y)
subdir-y := $(dts-dirs)
clean-files := *.dtb *.dtb.S