define list-defconfigs
	@first=true; \
	for defconfig in $(1)/configs/*_defconfig; do \
		[ -f "$${defconfig}" ] || continue; \
		if $${first}; then \
			if [ "$(2)" ]; then \
				printf 'External configs in "$(call qstrip,$(2))":\n'; \
			else \
				printf "Built-in configs:\n"; \
			fi; \
			first=false; \
		fi; \
		defconfig="$${defconfig##*/}"; \
		printf "  %-35s - Build for %s\n" "$${defconfig}" "$${defconfig%_defconfig}"; \
	done; \
	$${first} || printf "\n"
endef

.PHONY: list-defconfigs