eclass/cros-firmware.eclass - mirrors/cros/chromiumos/overlays/chromiumos-overlay - Git at Google

 # Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
 # Distributed under the terms of the GNU General Public License v2
 #
 # Original Author: The Chromium OS Authors <chromium-os-dev@chromium.org>
 # Purpose: Generate shell script containing firmware update bundle.
 #

 # Skip unibuild if we don't have a board set.
 if [[ ${#CROS_BOARDS[@]} -eq 0 ]]; then
 	CROS_BOARDS=( "none" )
 fi

 if [[ -z "${EBUILD}" ]]; then
 	die "This eclass needs EBUILD environment variable."
 fi

 inherit cros-workon cros-unibuild cros-constants

 # @ECLASS-VARIABLE: CROS_FIRMWARE_BCS_OVERLAY
 # @DESCRIPTION: (Optional) Name of board overlay on Binary Component Server
 : ${CROS_FIRMWARE_BCS_OVERLAY:=$(
 	# EBUILD will be the full path to the ebuild file.
 	IFS="/"
 	set -- ${EBUILD}
 	# Chop off the ebuild, the $PN dir, and the $CATEGORY dir.
 	n=$(( $# - 3 ))
 	echo "${!n}"
 )}

 # @ECLASS-VARIABLE: CROS_FIRMWARE_MAIN_IMAGE
 # @DESCRIPTION: (Optional) Location of system firmware (BIOS) image
 : ${CROS_FIRMWARE_MAIN_IMAGE:=}

 # @ECLASS-VARIABLE: CROS_FIRMWARE_MAIN_RW_IMAGE
 # @DESCRIPTION: (Optional) Location of RW system firmware image
 : ${CROS_FIRMWARE_MAIN_RW_IMAGE:=}

 # @ECLASS-VARIABLE: CROS_FIRMWARE_EC_IMAGE
 # @DESCRIPTION: (Optional) Location of EC firmware image
 : ${CROS_FIRMWARE_EC_IMAGE:=}

 # @ECLASS-VARIABLE: CROS_FIRMWARE_PD_IMAGE
 # @DESCRIPTION: (Optional) Location of PD firmware image
 : ${CROS_FIRMWARE_PD_IMAGE:=}

 # Check for EAPI 2+
 case "${EAPI:-0}" in
 0|1) die "unsupported EAPI (${EAPI}) in eclass (${ECLASS})" ;;
 *) ;;
 esac

 # $board-overlay/make.conf may contain these flags to always create "firmware
 # from source".
 IUSE="bootimage cros_ec cros_ish unibuild generated_cros_config"

 # "futility update" is needed when building and running updater package.
 COMMON_DEPEND=" chromeos-base/vboot_reference "

 # For unibuild we need EAPI 5 for the sub-slot dependency feature.
 case "${EAPI:-0}" in
 5|6|7)
 	COMMON_DEPEND+="
 		unibuild? (
 			!generated_cros_config? ( chromeos-base/chromeos-config )
 			generated_cros_config? ( chromeos-base/chromeos-config-bsp:= )
 		)
 	"
 	;;
 esac

 # Dependency for SFX v1 (needed by both build and run time).
 COMMON_DEPEND+="
 	app-arch/gzip
 	app-arch/sharutils
 	app-arch/tar
 	sys-apps/util-linux
 	"

 # Apply common dependency.
 DEPEND="${COMMON_DEPEND}"
 RDEPEND="${COMMON_DEPEND}"

 # Dependency for run time only (invoked by `futility update`).
 RDEPEND+="
 	chromeos-base/vpd
 	sys-apps/flashrom
 	sys-apps/mosys
 	cros_ish? ( chromeos-base/chromeos-ish )
 	"
 # Maintenance note:  The factory install shim downloads and executes
 # the firmware updater.  Consequently, run time dependencies for the
 # updater are also run time dependencies for the install shim.
 #
 # The contents of RDEPEND must also be present in the
 # chromeos-base/factory_installer ebuild in PROVIDED_DEPEND.  If you make any
 # change to the list above, you may need to make a matching change in the
 # factory_installer ebuild.

 # Dependency to build firmware from source (build phase only).
 DEPEND+="
 	bootimage? ( sys-boot/chromeos-bootimage )
 	cros_ec? ( chromeos-base/chromeos-ec )
 	"

 RESTRICT="mirror"

 # Local variables.

 UPDATE_SCRIPT="chromeos-firmwareupdate"
 FW_IMAGE_LOCATION=""
 FW_RW_IMAGE_LOCATION=""
 EC_IMAGE_LOCATION=""
 PD_IMAGE_LOCATION=""

 # Output the URI associated with a file to download. This can be added to the
 # SRC_URI variable.
 # Portage will then take care of downloading these files before the src_unpack
 # phase starts.
 # Args
 #   $1: Input file to read, with prefix (e.g. "bcs://Reef.9042.72.0.tbz2")
 #   $2: Overlay name (e.g. "reef-private")
 #   $3: Board directory containing file (e.g. "chromeos-firmware-reef")
 _add_uri() {
 	local input="$1"
 	local overlay="$2"
 	local board="$3"
 	local protocol="${input%%://*}"
 	local uri="${input#*://}"
 	local user="bcs-${overlay#variant-*-}"
 	local bcs_url="gs://chromeos-binaries/HOME/${user}/overlay-${overlay}"

 	# Input without ${protocol} are local files (ex, ${FILESDIR}/file).
 	case "${protocol}" in
 		bcs)
 			echo "${bcs_url}/${CATEGORY}/${board}/${uri}"
 			;;
 		http|https|gs)
 			echo "${input}"
 			;;
 	esac
 }

 # Output a URL for the given firmware variable.
 # This calls _add_uri() after setting up the required parameters.
 #  $1: Variable containing the required filename (e.g. "FW_IMAGE_LOCATION")
 _add_source() {
 	local var="$1"
 	local src_uri="$2"
 	local overlay="${CROS_FIRMWARE_BCS_OVERLAY#overlay-}"
 	local input="${!var}"

 	_add_uri "${input}" "${overlay}" "${PN}"
 }

 _unpack_archive() {
 	local var="$1"
 	local input="${!var}"
 	local archive="${input##*/}"
 	local folder="${S}/.dist/${archive}"

 	# Remote source files (bcs://, http://, ...) are downloaded into
 	# ${DISTDIR}, which is the default location for command 'unpack'.
 	# For any other files (ex, ${FILESDIR}/file), use complete file path.
 	local unpack_name="${input}"
 	if [[ "${unpack_name}" =~ "://" ]]; then
 		input="${DISTDIR}/${archive}"
 		unpack_name="${archive}"
 	fi

 	case "${input##*.}" in
 		tar|tbz2|tbz|bz|gz|tgz|zip|xz) ;;
 		*)
 			eval ${var}="'${input}'"
 			return
 			;;
 	esac

 	mkdir -p "${folder}" || die "Not able to create ${folder}"
 	(cd "${folder}" && unpack "${unpack_name}") ||
 		die "Failed to unpack ${unpack_name}."
 	local contents=($(ls "${folder}"))
 	if [[ ${#contents[@]} -gt 1 ]]; then
 		# Currently we can only serve one file (or directory).
 		ewarn "WARNING: package ${input} contains multiple files."
 	fi
 	eval ${var}="'${folder}/${contents}'"
 }

 cros-firmware_src_unpack() {
 	case "${EAPI:-0}" in
 	1|2|3|4)
 		use unibuild &&
 			die "Update your EAPI version to 5 to use unibuild"
 		;;
 	esac

 	cros-workon_src_unpack
 	local i

 	if ! use unibuild; then
 		for i in {FW,FW_RW,EC,PD}_IMAGE_LOCATION; do
 			_unpack_archive ${i}
 		done
 	fi
 }

 # Add members to an array.
 #  $1: Array variable to append to.
 #  $2..: Arguments to append, each to be put in its own array element.
 _append_var() {
 	local var="$1"
 	shift
 	eval "${var}+=( \"\$@\" )"
 }

 # Add a string command-line flag with its value to an array.
 # If the value is empty then this function does nothing.
 #  $1: Array variable to append to.
 #  $2: Flag (e.g. "-b").
 #  $3: Value (e.g. "bios.bin").
 _add_param() {
 	local var="$1"
 	local flag="$2"
 	local value="$3"

 	[[ -n "${value}" ]] && _append_var "${var}" "${flag}" "${value}"
 }

 # Add a string command-line flag with its file argument to an array.
 # If the file does not exists then this function does nothing.
 #  $1: Array variable to append to.
 #  $2: Flag (e.g. "-b").
 #  $3: File path (e.g. "bios.bin").
 _add_file_param() {
 	local var="$1"
 	local flag="$2"
 	local value="$3"

 	[[ -e "${value}" ]] && _append_var "${var}" "${flag}" "${value}"
 }

 # Add a boolean command-line flag to an array.
 # If the value is empty then this function does nothing, otherwise it
 # appends the flag.
 #  $1: Array variable to append to.
 #  $2: Flag (e.g. "--create_bios_rw_image").
 #  $3: Value (e.g. "${IMAGE}"), only used to determine flag presence.
 _add_bool_param() {
 	local var="$1"
 	local flag="$2"
 	local value="$3"

 	[[ -n "${value}" ]] && _append_var "${var}" "${flag}"
 }

 cros-firmware_src_compile() {
 	# image_cmd will be reset when creating local updaters.
 	# ext_cmd will be reused when creating local updaters.
 	local image_cmd=() ext_cmd=()
 	local root="${SYSROOT%/}"
 	local output="${UPDATE_SCRIPT}"

 	# We need lddtree from chromite.
 	export PATH="${CHROMITE_BIN_DIR}:${PATH}"

 	if use unibuild; then
 		_add_param ext_cmd -i "${DISTDIR}"
 		_add_param ext_cmd -c "${root}${UNIBOARD_YAML_CONFIG}"
 	else
 		ext_cmd+=(--legacy)
 		_add_param image_cmd -b "${FW_IMAGE_LOCATION}"
 		_add_param image_cmd -e "${EC_IMAGE_LOCATION}"
 		_add_param image_cmd -p "${PD_IMAGE_LOCATION}"
 		_add_param image_cmd -w "${FW_RW_IMAGE_LOCATION}"
 	fi

 	if [ ${#image_cmd[@]} -eq 0 ] && ! use unibuild; then
 		# Create an empty update script for the generic case
 		# (no need to update)
 		einfo "Building empty firmware update script"
 		echo -n >"${output}"
 	else
 		einfo "Build ${BOARD_USE} firmware updater to ${output}:" \
 			"${image_cmd[*]} ${ext_cmd[*]}"
 		./pack_firmware.py "${image_cmd[@]}" "${ext_cmd[@]}" \
 			-o "${output}" || die "Cannot pack firmware updater."
 	fi

 	if ! use bootimage; then
 		if use cros_ec; then
 			# TODO(hungte) Deal with a platform that has only EC and
 			# no BIOS, which is usually incorrect configuration.  We
 			# only warn here to allow for BCS based firmware to
 			# still generate a proper chromeos-firmwareupdate update
 			# script.
 			ewarn "WARNING: platform has no local BIOS."
 			ewarn "EC-only is not supported."
 			ewarn "Not generating a local updater script."
 		fi
 		return
 	fi

 	# Create local updaters. image_cmd is cleared and ext_cmd is kept.
 	image_cmd=()
 	output="updater.sh"
 	local local_root="${root}/firmware"
 	if use unibuild; then
 		ext_cmd+=(--local)
 		# Tell pack_firmware.py where to find the files.
 		# 'BUILD_TARGET' will be replaced with the build-targets config
 		# from the unified build config file. Since these path do not
 		# exist, we can't use _add_file_param.
 		_add_param image_cmd -b "${local_root}/image-BUILD_TARGET.bin"
 		local_root+="/BUILD_TARGET"
 		if use cros_ec; then
 			_add_param image_cmd -e "${local_root}/ec.bin"
 			_add_param image_cmd -p "${local_root}/pd.bin"
 		fi
 	else
 		_add_param image_cmd -b "${local_root}/image.bin"
 		_add_file_param image_cmd -e "${local_root}/ec.bin"
 		_add_file_param image_cmd -p "${local_root}/pd.bin"
 	fi

 	einfo "Build ${BOARD_USE} local firmware updater to ${output}:" \
 		"${image_cmd[*]} ${ext_cmd[*]}"
 	./pack_firmware.py -o "${output}" "${image_cmd[@]}" "${ext_cmd[@]}" ||
 		die "Cannot pack firmware updater."

 	if [[ ! -s "${UPDATE_SCRIPT}" ]]; then
 		# When no pre-built binaries are available,
 		# dupe local updater to system updater.
 		cp -f "${output}" "${UPDATE_SCRIPT}"
 	fi

 }

 cros-firmware_src_install() {
 	# install updaters for firmware-from-source archive.
 	if use bootimage; then
 		exeinto /firmware
 		doexe updater.sh
 	fi

 	# skip anything else if no main updater program.
 	if [[ ! -s "${UPDATE_SCRIPT}" ]]; then
 		return
 	fi

 	# install the main updater program if available.
 	dosbin "${UPDATE_SCRIPT}"

 	dosbin "${S}"/sbin/*
 	# install ${FILESDIR}/sbin/* (usually board-setgoodfirmware).
 	if [[ -d "${FILESDIR}"/sbin ]]; then
 		dosbin "${FILESDIR}"/sbin/*
 	fi
 }

 # Trigger tests on each firmware build. While there is a chromeos-firmware-1
 # ebuild which could be used to run these tests on the host, it doesn't do
 # anything at present, and the usual workflow is to build firmware for a
 # particular board. This way it is more likely that people will see any
 # failures in their normal workflow.
 cros-firmware_src_test() {
 	local fname

 	# We need lddtree from chromite.
 	export PATH="${CHROMITE_BIN_DIR}:${PATH}"

 	for fname in *test.py; do
 		einfo "Running tests in ${fname}"
 		python3 "./${fname}" || die "Tests failed at ${fname} (py3)"
 	done
 }

 # @FUNCTION: _expand_list
 # @USAGE <var> <ifs> <string>
 # @DESCRIPTION:
 # Internal function to expand a string (separated by ifs) into bash array.
 _expand_list() {
 	local var="$1" ifs="$2"
 	IFS="${ifs}" read -r -a ${var} <<<"${*:3}"
 }

 # @FUNCTION: cros-firmware_setup_source
 # @DESCRIPTION:
 # Configures all firmware binary source files to SRC_URI, and updates local
 # destination mapping (*_LOCATION). Must be invoked after CROS_FIRMWARE_*_IMAGE
 # are set. This also reads the master configuration if available and adds files
 # from there for unified builds. The result is something like:
 #
 # SRC_URI="!unibuild? ( file1 file2 ) unibuild? ( file3 file3 )"
 #
 # With this we will end up downloading either the unibuild files or the
 # !unibuild files, depending on the 'unibuild' USE flag.
 cros-firmware_setup_source() {
 	# This function is called before FILESDIR is set so figure it out from
 	# the ebuild filename.
 	local basedir="${EBUILD%/*}"
 	local files="${basedir}/files"
 	local i uris

 	if [[ -f "${files}/srcuris" ]]; then
 		mapfile -t uris < "${files}/srcuris"
 		SRC_URI+=" ${uris[*]}"
 		return
 	fi

 	FW_IMAGE_LOCATION="${CROS_FIRMWARE_MAIN_IMAGE}"
 	FW_RW_IMAGE_LOCATION="${CROS_FIRMWARE_MAIN_RW_IMAGE}"
 	EC_IMAGE_LOCATION="${CROS_FIRMWARE_EC_IMAGE}"
 	PD_IMAGE_LOCATION="${CROS_FIRMWARE_PD_IMAGE}"

 	# Add these files for use if unibuild is not set.
 	for i in {FW,FW_RW,EC,PD}_IMAGE_LOCATION; do
 		uris+=" $(_add_source ${i})"
 	done

 	if [[ -n "${uris// }" ]]; then
 		SRC_URI+="!unibuild? ( ${uris} ) "
 	fi
 }

 # If "inherit cros-firmware" appears at end of ebuild file, build source URI
 # automatically. Otherwise, you have to put an explicit call to
 # "cros-firmware_setup_source" at end of ebuild file.
 [[ -n "${CROS_FIRMWARE_MAIN_IMAGE}" ]] && cros-firmware_setup_source

 EXPORT_FUNCTIONS src_unpack src_compile src_install src_test
	# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
	# Distributed under the terms of the GNU General Public License v2
	#
	# Original Author: The Chromium OS Authors <chromium-os-dev@chromium.org>
	# Purpose: Generate shell script containing firmware update bundle.
	#

	# Skip unibuild if we don't have a board set.
	if [[ ${#CROS_BOARDS[@]} -eq 0 ]]; then
	CROS_BOARDS=( "none" )
	fi

	if [[ -z "${EBUILD}" ]]; then
	die "This eclass needs EBUILD environment variable."
	fi

	inherit cros-workon cros-unibuild cros-constants

	# @ECLASS-VARIABLE: CROS_FIRMWARE_BCS_OVERLAY
	# @DESCRIPTION: (Optional) Name of board overlay on Binary Component Server
	: ${CROS_FIRMWARE_BCS_OVERLAY:=$(
	# EBUILD will be the full path to the ebuild file.
	IFS="/"
	set -- ${EBUILD}
	# Chop off the ebuild, the $PN dir, and the $CATEGORY dir.
	n=$(( $# - 3 ))
	echo "${!n}"
	)}

	# @ECLASS-VARIABLE: CROS_FIRMWARE_MAIN_IMAGE
	# @DESCRIPTION: (Optional) Location of system firmware (BIOS) image
	: ${CROS_FIRMWARE_MAIN_IMAGE:=}

	# @ECLASS-VARIABLE: CROS_FIRMWARE_MAIN_RW_IMAGE
	# @DESCRIPTION: (Optional) Location of RW system firmware image
	: ${CROS_FIRMWARE_MAIN_RW_IMAGE:=}

	# @ECLASS-VARIABLE: CROS_FIRMWARE_EC_IMAGE
	# @DESCRIPTION: (Optional) Location of EC firmware image
	: ${CROS_FIRMWARE_EC_IMAGE:=}

	# @ECLASS-VARIABLE: CROS_FIRMWARE_PD_IMAGE
	# @DESCRIPTION: (Optional) Location of PD firmware image
	: ${CROS_FIRMWARE_PD_IMAGE:=}

	# Check for EAPI 2+
	case "${EAPI:-0}" in
	0\|1) die "unsupported EAPI (${EAPI}) in eclass (${ECLASS})" ;;
	*) ;;
	esac

	# $board-overlay/make.conf may contain these flags to always create "firmware
	# from source".
	IUSE="bootimage cros_ec cros_ish unibuild generated_cros_config"

	# "futility update" is needed when building and running updater package.
	COMMON_DEPEND=" chromeos-base/vboot_reference "

	# For unibuild we need EAPI 5 for the sub-slot dependency feature.
	case "${EAPI:-0}" in
	5\|6\|7)
	COMMON_DEPEND+="
	unibuild? (
	!generated_cros_config? ( chromeos-base/chromeos-config )
	generated_cros_config? ( chromeos-base/chromeos-config-bsp:= )
	)
	"
	;;
	esac

	# Dependency for SFX v1 (needed by both build and run time).
	COMMON_DEPEND+="
	app-arch/gzip
	app-arch/sharutils
	app-arch/tar
	sys-apps/util-linux
	"

	# Apply common dependency.
	DEPEND="${COMMON_DEPEND}"
	RDEPEND="${COMMON_DEPEND}"

	# Dependency for run time only (invoked by `futility update`).
	RDEPEND+="
	chromeos-base/vpd
	sys-apps/flashrom
	sys-apps/mosys
	cros_ish? ( chromeos-base/chromeos-ish )
	"
	# Maintenance note: The factory install shim downloads and executes
	# the firmware updater. Consequently, run time dependencies for the
	# updater are also run time dependencies for the install shim.
	#
	# The contents of RDEPEND must also be present in the
	# chromeos-base/factory_installer ebuild in PROVIDED_DEPEND. If you make any
	# change to the list above, you may need to make a matching change in the
	# factory_installer ebuild.

	# Dependency to build firmware from source (build phase only).
	DEPEND+="
	bootimage? ( sys-boot/chromeos-bootimage )
	cros_ec? ( chromeos-base/chromeos-ec )
	"

	RESTRICT="mirror"

	# Local variables.

	UPDATE_SCRIPT="chromeos-firmwareupdate"
	FW_IMAGE_LOCATION=""
	FW_RW_IMAGE_LOCATION=""
	EC_IMAGE_LOCATION=""
	PD_IMAGE_LOCATION=""

	# Output the URI associated with a file to download. This can be added to the
	# SRC_URI variable.
	# Portage will then take care of downloading these files before the src_unpack
	# phase starts.
	# Args
	# $1: Input file to read, with prefix (e.g. "bcs://Reef.9042.72.0.tbz2")
	# $2: Overlay name (e.g. "reef-private")
	# $3: Board directory containing file (e.g. "chromeos-firmware-reef")
	_add_uri() {
	local input="$1"
	local overlay="$2"
	local board="$3"
	local protocol="${input%%://*}"
	local uri="${input#*://}"
	local user="bcs-${overlay#variant-*-}"
	local bcs_url="gs://chromeos-binaries/HOME/${user}/overlay-${overlay}"

	# Input without ${protocol} are local files (ex, ${FILESDIR}/file).
	case "${protocol}" in
	bcs)
	echo "${bcs_url}/${CATEGORY}/${board}/${uri}"
	;;
	http\|https\|gs)
	echo "${input}"
	;;
	esac
	}

	# Output a URL for the given firmware variable.
	# This calls _add_uri() after setting up the required parameters.
	# $1: Variable containing the required filename (e.g. "FW_IMAGE_LOCATION")
	_add_source() {
	local var="$1"
	local src_uri="$2"
	local overlay="${CROS_FIRMWARE_BCS_OVERLAY#overlay-}"
	local input="${!var}"

	_add_uri "${input}" "${overlay}" "${PN}"
	}

	_unpack_archive() {
	local var="$1"
	local input="${!var}"
	local archive="${input##*/}"
	local folder="${S}/.dist/${archive}"

	# Remote source files (bcs://, http://, ...) are downloaded into
	# ${DISTDIR}, which is the default location for command 'unpack'.
	# For any other files (ex, ${FILESDIR}/file), use complete file path.
	local unpack_name="${input}"
	if [[ "${unpack_name}" =~ "://" ]]; then
	input="${DISTDIR}/${archive}"
	unpack_name="${archive}"
	fi

	case "${input##*.}" in
	tar\|tbz2\|tbz\|bz\|gz\|tgz\|zip\|xz) ;;
	*)
	eval ${var}="'${input}'"
	return
	;;
	esac

	mkdir -p "${folder}" \|\| die "Not able to create ${folder}"
	(cd "${folder}" && unpack "${unpack_name}") \|\|
	die "Failed to unpack ${unpack_name}."
	local contents=($(ls "${folder}"))
	if [[ ${#contents[@]} -gt 1 ]]; then
	# Currently we can only serve one file (or directory).
	ewarn "WARNING: package ${input} contains multiple files."
	fi
	eval ${var}="'${folder}/${contents}'"
	}

	cros-firmware_src_unpack() {
	case "${EAPI:-0}" in
	1\|2\|3\|4)
	use unibuild &&
	die "Update your EAPI version to 5 to use unibuild"
	;;
	esac

	cros-workon_src_unpack
	local i

	if ! use unibuild; then
	for i in {FW,FW_RW,EC,PD}_IMAGE_LOCATION; do
	_unpack_archive ${i}
	done
	fi
	}

	# Add members to an array.
	# $1: Array variable to append to.
	# $2..: Arguments to append, each to be put in its own array element.
	_append_var() {
	local var="$1"
	shift
	eval "${var}+=( \"\$@\" )"
	}

	# Add a string command-line flag with its value to an array.
	# If the value is empty then this function does nothing.
	# $1: Array variable to append to.
	# $2: Flag (e.g. "-b").
	# $3: Value (e.g. "bios.bin").
	_add_param() {
	local var="$1"
	local flag="$2"
	local value="$3"

	[[ -n "${value}" ]] && _append_var "${var}" "${flag}" "${value}"
	}

	# Add a string command-line flag with its file argument to an array.
	# If the file does not exists then this function does nothing.
	# $1: Array variable to append to.
	# $2: Flag (e.g. "-b").
	# $3: File path (e.g. "bios.bin").
	_add_file_param() {
	local var="$1"
	local flag="$2"
	local value="$3"

	[[ -e "${value}" ]] && _append_var "${var}" "${flag}" "${value}"
	}

	# Add a boolean command-line flag to an array.
	# If the value is empty then this function does nothing, otherwise it
	# appends the flag.
	# $1: Array variable to append to.
	# $2: Flag (e.g. "--create_bios_rw_image").
	# $3: Value (e.g. "${IMAGE}"), only used to determine flag presence.
	_add_bool_param() {
	local var="$1"
	local flag="$2"
	local value="$3"

	[[ -n "${value}" ]] && _append_var "${var}" "${flag}"
	}

	cros-firmware_src_compile() {
	# image_cmd will be reset when creating local updaters.
	# ext_cmd will be reused when creating local updaters.
	local image_cmd=() ext_cmd=()
	local root="${SYSROOT%/}"
	local output="${UPDATE_SCRIPT}"

	# We need lddtree from chromite.
	export PATH="${CHROMITE_BIN_DIR}:${PATH}"

	if use unibuild; then
	_add_param ext_cmd -i "${DISTDIR}"
	_add_param ext_cmd -c "${root}${UNIBOARD_YAML_CONFIG}"
	else
	ext_cmd+=(--legacy)
	_add_param image_cmd -b "${FW_IMAGE_LOCATION}"
	_add_param image_cmd -e "${EC_IMAGE_LOCATION}"
	_add_param image_cmd -p "${PD_IMAGE_LOCATION}"
	_add_param image_cmd -w "${FW_RW_IMAGE_LOCATION}"
	fi

	if [ ${#image_cmd[@]} -eq 0 ] && ! use unibuild; then
	# Create an empty update script for the generic case
	# (no need to update)
	einfo "Building empty firmware update script"
	echo -n >"${output}"
	else
	einfo "Build ${BOARD_USE} firmware updater to ${output}:" \
	"${image_cmd[]} ${ext_cmd[]}"
	./pack_firmware.py "${image_cmd[@]}" "${ext_cmd[@]}" \
	-o "${output}" \|\| die "Cannot pack firmware updater."
	fi

	if ! use bootimage; then
	if use cros_ec; then
	# TODO(hungte) Deal with a platform that has only EC and
	# no BIOS, which is usually incorrect configuration. We
	# only warn here to allow for BCS based firmware to
	# still generate a proper chromeos-firmwareupdate update
	# script.
	ewarn "WARNING: platform has no local BIOS."
	ewarn "EC-only is not supported."
	ewarn "Not generating a local updater script."
	fi
	return
	fi

	# Create local updaters. image_cmd is cleared and ext_cmd is kept.
	image_cmd=()
	output="updater.sh"
	local local_root="${root}/firmware"
	if use unibuild; then
	ext_cmd+=(--local)
	# Tell pack_firmware.py where to find the files.
	# 'BUILD_TARGET' will be replaced with the build-targets config
	# from the unified build config file. Since these path do not
	# exist, we can't use _add_file_param.
	_add_param image_cmd -b "${local_root}/image-BUILD_TARGET.bin"
	local_root+="/BUILD_TARGET"
	if use cros_ec; then
	_add_param image_cmd -e "${local_root}/ec.bin"
	_add_param image_cmd -p "${local_root}/pd.bin"
	fi
	else
	_add_param image_cmd -b "${local_root}/image.bin"
	_add_file_param image_cmd -e "${local_root}/ec.bin"
	_add_file_param image_cmd -p "${local_root}/pd.bin"
	fi

	einfo "Build ${BOARD_USE} local firmware updater to ${output}:" \
	"${image_cmd[]} ${ext_cmd[]}"
	./pack_firmware.py -o "${output}" "${image_cmd[@]}" "${ext_cmd[@]}" \|\|
	die "Cannot pack firmware updater."

	if [[ ! -s "${UPDATE_SCRIPT}" ]]; then
	# When no pre-built binaries are available,
	# dupe local updater to system updater.
	cp -f "${output}" "${UPDATE_SCRIPT}"
	fi

	}

	cros-firmware_src_install() {
	# install updaters for firmware-from-source archive.
	if use bootimage; then
	exeinto /firmware
	doexe updater.sh
	fi

	# skip anything else if no main updater program.
	if [[ ! -s "${UPDATE_SCRIPT}" ]]; then
	return
	fi

	# install the main updater program if available.
	dosbin "${UPDATE_SCRIPT}"

	dosbin "${S}"/sbin/*
	# install ${FILESDIR}/sbin/* (usually board-setgoodfirmware).
	if [[ -d "${FILESDIR}"/sbin ]]; then
	dosbin "${FILESDIR}"/sbin/*
	fi
	}

	# Trigger tests on each firmware build. While there is a chromeos-firmware-1
	# ebuild which could be used to run these tests on the host, it doesn't do
	# anything at present, and the usual workflow is to build firmware for a
	# particular board. This way it is more likely that people will see any
	# failures in their normal workflow.
	cros-firmware_src_test() {
	local fname

	# We need lddtree from chromite.
	export PATH="${CHROMITE_BIN_DIR}:${PATH}"

	for fname in *test.py; do
	einfo "Running tests in ${fname}"
	python3 "./${fname}" \|\| die "Tests failed at ${fname} (py3)"
	done
	}

	# @FUNCTION: _expand_list
	# @USAGE <var> <ifs> <string>
	# @DESCRIPTION:
	# Internal function to expand a string (separated by ifs) into bash array.
	_expand_list() {
	local var="$1" ifs="$2"
	IFS="${ifs}" read -r -a ${var} <<<"${*:3}"
	}

	# @FUNCTION: cros-firmware_setup_source
	# @DESCRIPTION:
	# Configures all firmware binary source files to SRC_URI, and updates local
	# destination mapping (_LOCATION). Must be invoked after CROS_FIRMWARE__IMAGE
	# are set. This also reads the master configuration if available and adds files
	# from there for unified builds. The result is something like:
	#
	# SRC_URI="!unibuild? ( file1 file2 ) unibuild? ( file3 file3 )"
	#
	# With this we will end up downloading either the unibuild files or the
	# !unibuild files, depending on the 'unibuild' USE flag.
	cros-firmware_setup_source() {
	# This function is called before FILESDIR is set so figure it out from
	# the ebuild filename.
	local basedir="${EBUILD%/*}"
	local files="${basedir}/files"
	local i uris

	if [[ -f "${files}/srcuris" ]]; then
	mapfile -t uris < "${files}/srcuris"
	SRC_URI+=" ${uris[*]}"
	return
	fi

	FW_IMAGE_LOCATION="${CROS_FIRMWARE_MAIN_IMAGE}"
	FW_RW_IMAGE_LOCATION="${CROS_FIRMWARE_MAIN_RW_IMAGE}"
	EC_IMAGE_LOCATION="${CROS_FIRMWARE_EC_IMAGE}"
	PD_IMAGE_LOCATION="${CROS_FIRMWARE_PD_IMAGE}"

	# Add these files for use if unibuild is not set.
	for i in {FW,FW_RW,EC,PD}_IMAGE_LOCATION; do
	uris+=" $(_add_source ${i})"
	done

	if [[ -n "${uris// }" ]]; then
	SRC_URI+="!unibuild? ( ${uris} ) "
	fi
	}

	# If "inherit cros-firmware" appears at end of ebuild file, build source URI
	# automatically. Otherwise, you have to put an explicit call to
	# "cros-firmware_setup_source" at end of ebuild file.
	[[ -n "${CROS_FIRMWARE_MAIN_IMAGE}" ]] && cros-firmware_setup_source

	EXPORT_FUNCTIONS src_unpack src_compile src_install src_test