function compile_firmware_light_and_possibly_full() {
	if [[ "${INSTALL_ARMBIAN_FIRMWARE:-yes}" == "yes" ]]; then # Build firmware by default.
		# Build the "light" version of firmware packages, with no conditions.
		FULL="" REPLACE="-full" LOG_SECTION="compile_firmware" do_with_logging compile_firmware

		# Now, we'll build the "full" version of firmware packages, if:
		# 1) We've CI==true, or stdout is not a terminal, or
		# 2) We've been asked to install it for the board being built, BOARD_FIRMWARE_INSTALL="-full"
		if [[ "${CI}" == "true" || ! -t 1 || "${BOARD_FIRMWARE_INSTALL}" == "-full" ]]; then
			# Build the full version of firmware package
			FULL="-full" REPLACE="" LOG_SECTION="compile_firmware_full" do_with_logging compile_firmware
		else
			display_alert "Skipping full firmware package build" "" "info"
		fi
	fi
	return 0
}

function compile_firmware() {
	display_alert "Merging and packaging linux firmware" "@host --> firmware${FULL}" "info"

	local firmwaretempdir fw_dir

	firmwaretempdir=$(mktemp -d) # subject to TMPDIR/WORKDIR, so is protected by single/common error trapmanager to clean-up.
	chmod 700 "${firmwaretempdir}"

	fw_dir="armbian-firmware${FULL}"
	mkdir -p "${firmwaretempdir}/${fw_dir}/lib/firmware"

	local ARMBIAN_FIRMWARE_GIT_SOURCE="${ARMBIAN_FIRMWARE_GIT_SOURCE:-"https://github.com/armbian/firmware"}"
	local ARMBIAN_FIRMWARE_GIT_BRANCH="${ARMBIAN_FIRMWARE_GIT_BRANCH:-"master"}"

	# Fetch Armbian firmware from git.
	fetch_from_repo "${ARMBIAN_FIRMWARE_GIT_SOURCE}" "armbian-firmware-git" "branch:${ARMBIAN_FIRMWARE_GIT_BRANCH}"

	if [[ -n $FULL ]]; then
		# Fetch kernel firmware from git. This is huge...
		fetch_from_repo "$MAINLINE_FIRMWARE_SOURCE" "linux-firmware-git" "branch:main"

		# @TODO: rpardini: what is this thing with hardlinks? why?
		# cp : create hardlinks
		run_host_command_logged cp -af --reflink=auto "${SRC}/cache/sources/linux-firmware-git/*" "${firmwaretempdir}/${fw_dir}/lib/firmware/"
		# cp : create hardlinks for ath11k WCN685x hw2.1 firmware since they are using the same firmware with hw2.0
		run_host_command_logged cp -af --reflink=auto "${firmwaretempdir}/${fw_dir}/lib/firmware/ath11k/WCN6855/hw2.0/" "${firmwaretempdir}/${fw_dir}/lib/firmware/ath11k/WCN6855/hw2.1/"

		rm -rf "${firmwaretempdir}/${fw_dir}"/lib/firmware/.git # @TODO: would have been better not to waste I/O putting in there to begin with.
	fi

	# overlay Armbian's firmware on top of the mainline firmware
	run_host_command_logged cp -af --reflink=auto "${SRC}/cache/sources/armbian-firmware-git/*" "${firmwaretempdir}/${fw_dir}/lib/firmware/"

	rm -rf "${firmwaretempdir}/${fw_dir}"/lib/firmware/.git # @TODO: would have been better not to waste I/O putting in there to begin with.
	cd "${firmwaretempdir}/${fw_dir}" || exit_with_error "can't change directory"

	# set up control file
	mkdir -p DEBIAN
	# @TODO: rpardini: this needs Conflicts: with the standard Ubuntu/Debian linux-firmware packages and other firmware pkgs in Debian
	cat <<- END > DEBIAN/control
		Package: armbian-firmware${FULL}
		Version: $REVISION
		Architecture: all
		Maintainer: $MAINTAINER <$MAINTAINERMAIL>
		Installed-Size: 1
		Replaces: linux-firmware, firmware-brcm80211, firmware-ralink, firmware-samsung, firmware-realtek, armbian-firmware${REPLACE}
		Section: kernel
		Priority: optional
		Description: Armbian - Linux firmware${FULL}
	END

	cd "${firmwaretempdir}" || exit_with_error "can't change directory"
	# pack
	mv "armbian-firmware${FULL}" "armbian-firmware${FULL}_${REVISION}_all"
	display_alert "Building firmware package" "armbian-firmware${FULL}_${REVISION}_all" "info"
	fakeroot_dpkg_deb_build "armbian-firmware${FULL}_${REVISION}_all"
	mv "armbian-firmware${FULL}_${REVISION}_all" "armbian-firmware${FULL}"
	run_host_command_logged rsync -rq "armbian-firmware${FULL}_${REVISION}_all.deb" "${DEB_STORAGE}/"
}