Makefile - kernel/msm-extra/devicetree - Git at Google

 dtb-$(CONFIG_ARCH_MSM8909) += custom-overlay.dtb

 $(obj)/%.dtb: $(src)/%.dts FORCE
 	$(call if_changed_dep,dtc)

 dtbs: $(addprefix $(obj)/,$(dtb-y))
 clean-files := *.dtb
	dtb-$(CONFIG_ARCH_MSM8909) += custom-overlay.dtb

	$(obj)/%.dtb: $(src)/%.dts FORCE
	$(call if_changed_dep,dtc)

	dtbs: $(addprefix $(obj)/,$(dtb-y))
	clean-files := *.dtb