+DEVICE_EXTRA_PACKAGES = $(call qstrip,$(CONFIG_TARGET_DEVICE_PACKAGES_$(call target_conf,$(BOARD)$(if $(SUBTARGET),_$(SUBTARGET)))_DEVICE_$(1)))
+
+define merge_packages
+ $(1) :=
+ $(foreach pkg,$(2),
+ $(1) := $$(strip $$(filter-out -$$(patsubst -%,%,$(pkg)) $$(patsubst -%,%,$(pkg)),$$($(1))) $(pkg))
+ )
+endef
+