sys-boot/coreboot/coreboot-9999.ebuild - third_party/overlays/chromiumos-overlay - Git at Google

 # Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
 # Distributed under the terms of the GNU General Public License v2

 # Change this version number when any change is made to configs/files under
 # coreboot and an auto-revbump is required.
 # VERSION=REVBUMP-0.0.71

 EAPI=7
 CROS_WORKON_PROJECT=(
 	"chromiumos/third_party/coreboot"
 	"chromiumos/third_party/arm-trusted-firmware"
 	"chromiumos/platform/vboot_reference"
 	"chromiumos/third_party/coreboot/amd_blobs"
 	"chromiumos/third_party/coreboot/blobs"
 	"chromiumos/third_party/coreboot/intel-microcode"
 	"chromiumos/third_party/cbootimage"
 )
 CROS_WORKON_LOCALNAME=(
 	"coreboot"
 	"arm-trusted-firmware"
 	"../platform/vboot_reference"
 	"coreboot/3rdparty/amd_blobs"
 	"coreboot/3rdparty/blobs"
 	"coreboot/3rdparty/intel-microcode"
 	"cbootimage"
 )
 CROS_WORKON_DESTDIR=(
 	"${S}"
 	"${S}/3rdparty/arm-trusted-firmware"
 	"${S}/3rdparty/vboot"
 	"${S}/3rdparty/amd_blobs"
 	"${S}/3rdparty/blobs"
 	"${S}/3rdparty/intel-microcode"
 	"${S}/util/nvidia/cbootimage"
 )

 CROS_WORKON_EGIT_BRANCH=(
 	"chromeos-2016.05"
 	"master"
 	"master"
 	"chromeos"
 	"master"
 	"master"
 	"master"
 )

 inherit cros-workon toolchain-funcs cros-unibuild coreboot-sdk

 DESCRIPTION="coreboot firmware"
 HOMEPAGE="http://www.coreboot.org"
 LICENSE="GPL-2"
 KEYWORDS="~*"
 IUSE="em100-mode fsp memmaps mocktpm quiet-cb rmt vmx mma"
 IUSE="${IUSE} +bmpblk quiet unibuild verbose"
 IUSE="${IUSE} amd_cpu coreboot-sdk chipset_stoneyridge chipset_picasso"
 IUSE="${IUSE} chipset_cezanne"
 # virtual/coreboot-private-files is deprecated. When adding a new board you
 # should add the coreboot-private-files-{board/chipset} ebuilds into the private
 # overlays, and avoid creating virtual packages.
 # See b/178642474
 IUSE="${IUSE} coreboot-private-files-board coreboot-private-files-chipset"

 # No pre-unibuild boards build firmware on ToT anymore.  Assume
 # unibuild to keep ebuild clean.
 REQUIRED_USE="unibuild"

 # coreboot's build system handles stripping the binaries and producing a
 # separate .debug file with the symbols. This flag prevents portage from
 # stripping the .debug symbols
 RESTRICT="strip"

 DEPEND="
 	coreboot-private-files-board? ( sys-boot/coreboot-private-files-board:= )
 	coreboot-private-files-chipset? ( sys-boot/coreboot-private-files-chipset:= )
 	virtual/coreboot-private-files
 	bmpblk? ( sys-boot/chromeos-bmpblk:= )
 	chipset_stoneyridge? ( sys-boot/amd-firmware:= )
 	chipset_picasso? ( >=sys-boot/amd-picasso-fsp-0.0.2:= )
 	chipset_cezanne? ( sys-boot/amd-cezanne-fsp:= )
 	chromeos-base/chromeos-config:=
 	"

 # While this package is never actually executed, we still need to specify
 # RDEPEND. A binary version of this package could exist that was built using an
 # outdated version of chromeos-config. Without the RDEPEND this stale binary
 # package is considered valid by the package manager. This is problematic
 # because we could have two binary packages installed having been build with
 # different versions of chromeos-config. By specifying the RDEPEND we force
 # the package manager to ensure the two versions use the same chromeos-config.
 RDEPEND="${DEPEND}"

 set_build_env() {
 	local board="$1"

 	CONFIG="$(cros-workon_get_build_dir)/${board}.config"
 	CONFIG_SERIAL="$(cros-workon_get_build_dir)/${board}-serial.config"
 	# Strip the .config suffix
 	BUILD_DIR="${CONFIG%.config}"
 	BUILD_DIR_SERIAL="${CONFIG_SERIAL%.config}"
 }

 # Create the coreboot configuration files for a particular board. This
 # creates a standard config and a serial config.
 # Args:
 #   $1: board name
 #   $2: libpayload build target (for config.baseboard files)
 create_config() {
 	local board="$1"
 	local base_board="$2"

 	if [[ -s "${FILESDIR}/configs/config.${board}" ]]; then
 		touch "${CONFIG}"

 		if [[ -s "${FILESDIR}/configs/config.baseboard.${base_board}" ]]; then
 			cat "${FILESDIR}/configs/config.baseboard.${base_board}" >> "${CONFIG}"
 			# handle the case when "${CONFIG}" does not have a newline in the end.
 			echo >> "${CONFIG}"
 		fi

 		cat "${FILESDIR}/configs/config.${board}" >> "${CONFIG}"

 		# handle the case when "${CONFIG}" does not have a newline in the end.
 		echo >> "${CONFIG}"

 		# Override mainboard vendor if needed.
 		if [[ -n "${SYSTEM_OEM}" ]]; then
 			echo "CONFIG_MAINBOARD_VENDOR=\"${SYSTEM_OEM}\"" >> "${CONFIG}"
 		fi
 		if [[ -n "${SYSTEM_OEM_VENDOR_ID}" ]]; then
 			echo "CONFIG_SUBSYSTEM_VENDOR_ID=${SYSTEM_OEM_VENDOR_ID}" >> "${CONFIG}"
 		fi
 		if [[ -n "${SYSTEM_OEM_DEVICE_ID}" ]]; then
 			echo "CONFIG_SUBSYSTEM_DEVICE_ID=${SYSTEM_OEM_DEVICE_ID}" >> "${CONFIG}"
 		fi
 		if [[ -n "${SYSTEM_OEM_ACPI_ID}" ]]; then
 			echo "CONFIG_ACPI_SUBSYSTEM_ID=\"${SYSTEM_OEM_ACPI_ID}\"" >> "${CONFIG}"
 		fi

 		# In case config comes from a symlink we are likely building
 		# for an overlay not matching this config name. Enable adding
 		# a CBFS based board ID for coreboot.
 		if [[ -L "${FILESDIR}/configs/config.${board}" ]]; then
 			echo "CONFIG_BOARD_ID_MANUAL=y" >> "${CONFIG}"
 			echo "CONFIG_BOARD_ID_STRING=\"${BOARD_USE}\"" >> "${CONFIG}"
 		fi
 	else
 		ewarn "Could not find existing config for ${board}."
 	fi

 	if use rmt; then
 		echo "CONFIG_MRC_RMT=y" >> "${CONFIG}"
 	fi
 	if use vmx; then
 		elog "   - enabling VMX"
 		echo "CONFIG_ENABLE_VMX=y" >> "${CONFIG}"
 	fi
 	if use quiet-cb; then
 		# Suppress console spew if requested.
 		cat >> "${CONFIG}" <<EOF
 CONFIG_DEFAULT_CONSOLE_LOGLEVEL=3
 # CONFIG_DEFAULT_CONSOLE_LOGLEVEL_8 is not set
 CONFIG_DEFAULT_CONSOLE_LOGLEVEL_3=y
 EOF
 	fi
 	if use mocktpm; then
 		echo "CONFIG_VBOOT_MOCK_SECDATA=y" >> "${CONFIG}"
 	fi
 	if use mma; then
 		echo "CONFIG_MMA=y" >> "${CONFIG}"
 	fi

 	# disable coreboot's own EC firmware building mechanism
 	echo "CONFIG_EC_GOOGLE_CHROMEEC_FIRMWARE_NONE=y" >> "${CONFIG}"
 	echo "CONFIG_EC_GOOGLE_CHROMEEC_PD_FIRMWARE_NONE=y" >> "${CONFIG}"
 	# enable common GBB flags for development
 	echo "CONFIG_GBB_FLAG_DEV_SCREEN_SHORT_DELAY=y" >> "${CONFIG}"
 	echo "CONFIG_GBB_FLAG_DISABLE_FW_ROLLBACK_CHECK=y" >> "${CONFIG}"
 	echo "CONFIG_GBB_FLAG_FORCE_DEV_BOOT_USB=y" >> "${CONFIG}"
 	echo "CONFIG_GBB_FLAG_FORCE_DEV_SWITCH_ON=y" >> "${CONFIG}"
 	local version=$(${CHROOT_SOURCE_ROOT}/src/third_party/chromiumos-overlay/chromeos/config/chromeos_version.sh |grep "^[[:space:]]*CHROMEOS_VERSION_STRING=" |cut -d= -f2)
 	echo "CONFIG_VBOOT_FWID_VERSION=\".${version}\"" >> "${CONFIG}"
 	if use em100-mode; then
 		einfo "Enabling em100 mode via CONFIG_EM100 (slower SPI flash)"
 		echo "CONFIG_EM100=y" >> "${CONFIG}"
 	fi
 	# Use FSP's GOP in favor of coreboot's Ada based Intel graphics init
 	# which we don't include at this time. A no-op on non-FSP/GOP devices.
 	echo "CONFIG_RUN_FSP_GOP=y" >> "${CONFIG}"

 	cp "${CONFIG}" "${CONFIG_SERIAL}"
 	file="${FILESDIR}/configs/fwserial.${board}"
 	if [ ! -f "${file}" ] && [ -n "${base_board}" ]; then
 		file="${FILESDIR}/configs/fwserial.${base_board}"
 	fi
 	if [ ! -f "${file}" ]; then
 		file="${FILESDIR}/configs/fwserial.default"
 	fi
 	cat "${file}" >> "${CONFIG_SERIAL}" || die
 	# handle the case when "${CONFIG_SERIAL}" does not have a newline in the end.
 	echo >> "${CONFIG_SERIAL}"

 	# Check that we're using coreboot-sdk
 	if ! use coreboot-sdk; then
 		die "Enable coreboot-sdk to build coreboot."
 	fi
 	if grep -q "^CONFIG_ANY_TOOLCHAIN=y" "${CONFIG}"; then
 		die "Drop ANY_TOOLCHAIN from ${CONFIG}: we don't support it anymore."
 	fi

 	einfo "Configured ${CONFIG} for board ${board} in ${BUILD_DIR}"
 }

 src_prepare() {
 	local froot="${SYSROOT}/firmware"
 	local privdir="${SYSROOT}/firmware/coreboot-private"
 	local file

 	default

 	export GENERIC_COMPILER_PREFIX="invalid"

 	mkdir "$(cros-workon_get_build_dir)"

 	if [[ -d "${privdir}" ]]; then
 		while read -d $'\0' -r file; do
 			rsync --recursive --links --executability \
 				"${file}" ./ || die
 		done < <(find "${privdir}" -maxdepth 1 -mindepth 1 -print0)
 	fi

 	cp -a "${FILESDIR}/3rdparty/"* 3rdparty

 	local name
 	local coreboot
 	local libpayload
 	while read -r name; do
 		read -r coreboot
 		read -r libpayload
 		set_build_env "${coreboot}"
 		create_config "${coreboot}" "${libpayload}"
 	done < <(cros_config_host "get-firmware-build-combinations" \
 		coreboot,libpayload || die)
 }

 add_fw_blob() {
 	local rom="$1"
 	local cbname="$2"
 	local blob="$3"
 	local cbhash="${cbname%.bin}.hash"
 	local hash="${blob%.bin}.hash"

 	cbfstool "${rom}" add -r FW_MAIN_A,FW_MAIN_B -t raw -c lzma \
 		-f "${blob}" -n "${cbname}" || die
 	cbfstool "${rom}" add -r FW_MAIN_A,FW_MAIN_B -t raw -c none \
 		-f "${hash}" -n "${cbhash}" || die
 }

 # Build coreboot with a supplied configuration and output directory.
 #   $1: Build directory to use (e.g. "build_serial")
 #   $2: Config file to use (e.g. ".config_serial")
 #   $3: Build target build (e.g. "pyro")
 make_coreboot() {
 	local builddir="$1"
 	local config_fname="$2"

 	rm -rf "${builddir}" .xcompile

 	local CB_OPTS=(
 		obj="${builddir}"
 		DOTCONFIG="${config_fname}"
 		HOSTCC="$(tc-getBUILD_CC)"
 		HOSTCXX="$(tc-getBUILD_CXX)"
 		HOSTPKGCONFIG="$(tc-getBUILD_PKG_CONFIG)"
 	)
 	use quiet && CB_OPTS+=( "V=0" )
 	use verbose && CB_OPTS+=( "V=1" )
 	use quiet && REDIR="/dev/null" || REDIR="/dev/stdout"

 	# Configure and build coreboot.
 	yes "" | emake oldconfig "${CB_OPTS[@]}" >${REDIR}
 	emake "${CB_OPTS[@]}"

 	# Expand FW_MAIN_* since we might add some files
 	cbfstool "${builddir}/coreboot.rom" expand -r FW_MAIN_A,FW_MAIN_B

 	# Modify firmware descriptor if building for the EM100 emulator on
 	# Intel platforms.
 	# TODO(crbug.com/863396): Should we have an 'intel' USE flag? Do we
 	# still have any Intel platforms that don't use ifdtool?
 	if ! use amd_cpu && use em100-mode; then
 		einfo "Enabling em100 mode via ifdttool (slower SPI flash)"
 		ifdtool --em100 "${builddir}/coreboot.rom" || die
 		mv "${builddir}/coreboot.rom"{.new,} || die
 	fi
 }

 # Add fw blobs to the coreboot.rom.
 #   $1: Build directory to use (e.g. "build_serial")
 #   $2: Build target build (e.g. "pyro")
 add_fw_blobs() {
 	local builddir="$1"
 	local build_target="$2"
 	local froot="${SYSROOT}/firmware/${build_target}"
 	local fblobroot="${SYSROOT}/firmware"

 	local blob
 	local cbname
 	for blob in ${FW_BLOBS}; do
 		local blobfile="${fblobroot}/${blob}"

 		# Use per-board blob if available
 		if [[ -e "${froot}/${blob}" ]]; then
 			blobfile="${froot}/${blob}"
 		fi

 		cbname=$(basename "${blob}")
 		add_fw_blob "${builddir}/coreboot.rom" "${cbname}" \
 			"${blobfile}" || die
 	done

 	if [ -d ${froot}/cbfs ]; then
 		die "something is still using ${froot}/cbfs, which is deprecated."
 	fi
 }

 src_compile() {
 	# Set KERNELREVISION (really coreboot revision) to the ebuild revision
 	# number followed by a dot and the first seven characters of the git
 	# hash. The name is confusing but consistent with the coreboot
 	# Makefile.
 	local sha1v="${VCSID/*-/}"
 	export KERNELREVISION=".${PV}.${sha1v:0:7}"

 	if ! use coreboot-sdk; then
 		tc-export CC
 		# Export the known cross compilers so there isn't a reliance
 		# on what the default profile is for exporting a compiler. The
 		# reasoning is that the firmware may need more than one to build
 		# and boot.
 		export CROSS_COMPILE_x86="i686-pc-linux-gnu-"
 		export CROSS_COMPILE_mipsel="mipsel-cros-linux-gnu-"
 		export CROSS_COMPILE_arm64="aarch64-cros-linux-gnu-"
 		export CROSS_COMPILE_arm="armv7a-cros-linux-gnu- armv7a-cros-linux-gnueabihf-"
 	else
 		export CROSS_COMPILE_x86=${COREBOOT_SDK_PREFIX_x86_32}
 		export CROSS_COMPILE_mipsel=${COREBOOT_SDK_PREFIX_mips}
 		export CROSS_COMPILE_arm64=${COREBOOT_SDK_PREFIX_arm64}
 		export CROSS_COMPILE_arm=${COREBOOT_SDK_PREFIX_arm}

 		export PATH=/opt/coreboot-sdk/bin:$PATH
 	fi

 	use verbose && elog "Toolchain:\n$(sh util/xcompile/xcompile)\n"

 	while read -r name; do
 		read -r coreboot

 		set_build_env "${coreboot}"
 		make_coreboot "${BUILD_DIR}" "${CONFIG}"
 		add_fw_blobs "${BUILD_DIR}" "${coreboot}"

 		# Build a second ROM with serial support for developers.
 		make_coreboot "${BUILD_DIR_SERIAL}" "${CONFIG_SERIAL}"
 		add_fw_blobs "${BUILD_DIR_SERIAL}" "${coreboot}"
 	done < <(cros_config_host "get-firmware-build-combinations" coreboot || die)
 }

 # Install files into /firmware
 # Args:
 #   $1: The build combination name
 #   $2: The coreboot build target
 do_install() {
 	local build_combination="$1"
 	local build_target="$2"
 	local dest_dir="/firmware"
 	local mapfile

 	if [[ -n "${build_target}" ]]; then
 		dest_dir+="/${build_target}"
 		einfo "Installing coreboot ${build_target} into ${dest_dir}"
 	fi
 	insinto "${dest_dir}"

 	newins "${BUILD_DIR}/coreboot.rom" coreboot.rom
 	newins "${BUILD_DIR_SERIAL}/coreboot.rom" coreboot.rom.serial

 	OPROM=$( awk 'BEGIN{FS="\""} /CONFIG_VGA_BIOS_FILE=/ { print $2 }' \
 		"${CONFIG}" )
 	CBFSOPROM=pci$( awk 'BEGIN{FS="\""} /CONFIG_VGA_BIOS_ID=/ { print $2 }' \
 		"${CONFIG}" ).rom
 	FSP=$( awk 'BEGIN{FS="\""} /CONFIG_FSP_FILE=/ { print $2 }' \
 		"${CONFIG}" )
 	if [[ -n "${FSP}" ]]; then
 		newins ${FSP} fsp.bin
 	fi
 	# Save the psp_verstage binary for signing on AMD Fam17h platforms
 	if [[ -e "${BUILD_DIR}/psp_verstage.bin" ]]; then
 		newins "${BUILD_DIR}/psp_verstage.bin" psp_verstage.bin
 	fi
 	if [[ -n "${OPROM}" ]]; then
 		newins ${OPROM} ${CBFSOPROM}
 	fi
 	if use memmaps; then
 		for mapfile in "${BUILD_DIR}"/cbfs/fallback/*.map
 		do
 			doins $mapfile
 		done
 	fi
 	newins "${CONFIG}" coreboot.config
 	newins "${CONFIG_SERIAL}" coreboot_serial.config

 	# Keep binaries with debug symbols around for crash dump analysis
 	if [[ -s "${BUILD_DIR}/bl31.elf" ]]; then
 		newins "${BUILD_DIR}/bl31.elf" bl31.elf
 		newins "${BUILD_DIR_SERIAL}/bl31.elf" bl31.serial.elf
 	fi
 	insinto "${dest_dir}"/coreboot
 	doins "${BUILD_DIR}"/cbfs/fallback/*.debug
 	nonfatal doins "${BUILD_DIR}"/cbfs/fallback/bootblock.bin
 	insinto "${dest_dir}"/coreboot_serial
 	doins "${BUILD_DIR_SERIAL}"/cbfs/fallback/*.debug
 	nonfatal doins "${BUILD_DIR_SERIAL}"/cbfs/fallback/bootblock.bin

 	# coreboot's static_fw_config.h is copied into libpayload include
 	# directory.
 	insinto "/firmware/${build_combination}/libpayload/libpayload/include"
 	doins "${BUILD_DIR}/static_fw_config.h"
 	einfo "Installed static_fw_config.h into libpayload include directory"
 }

 src_install() {
 	while read -r name; do
 		read -r coreboot

 		set_build_env "${coreboot}"
 		do_install "${name}" "${coreboot}"
 	done < <(cros_config_host "get-firmware-build-combinations" coreboot || die)
 }
	# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
	# Distributed under the terms of the GNU General Public License v2

	# Change this version number when any change is made to configs/files under
	# coreboot and an auto-revbump is required.
	# VERSION=REVBUMP-0.0.71

	EAPI=7
	CROS_WORKON_PROJECT=(
	"chromiumos/third_party/coreboot"
	"chromiumos/third_party/arm-trusted-firmware"
	"chromiumos/platform/vboot_reference"
	"chromiumos/third_party/coreboot/amd_blobs"
	"chromiumos/third_party/coreboot/blobs"
	"chromiumos/third_party/coreboot/intel-microcode"
	"chromiumos/third_party/cbootimage"
	)
	CROS_WORKON_LOCALNAME=(
	"coreboot"
	"arm-trusted-firmware"
	"../platform/vboot_reference"
	"coreboot/3rdparty/amd_blobs"
	"coreboot/3rdparty/blobs"
	"coreboot/3rdparty/intel-microcode"
	"cbootimage"
	)
	CROS_WORKON_DESTDIR=(
	"${S}"
	"${S}/3rdparty/arm-trusted-firmware"
	"${S}/3rdparty/vboot"
	"${S}/3rdparty/amd_blobs"
	"${S}/3rdparty/blobs"
	"${S}/3rdparty/intel-microcode"
	"${S}/util/nvidia/cbootimage"
	)

	CROS_WORKON_EGIT_BRANCH=(
	"chromeos-2016.05"
	"master"
	"master"
	"chromeos"
	"master"
	"master"
	"master"
	)

	inherit cros-workon toolchain-funcs cros-unibuild coreboot-sdk

	DESCRIPTION="coreboot firmware"
	HOMEPAGE="http://www.coreboot.org"
	LICENSE="GPL-2"
	KEYWORDS="~*"
	IUSE="em100-mode fsp memmaps mocktpm quiet-cb rmt vmx mma"
	IUSE="${IUSE} +bmpblk quiet unibuild verbose"
	IUSE="${IUSE} amd_cpu coreboot-sdk chipset_stoneyridge chipset_picasso"
	IUSE="${IUSE} chipset_cezanne"
	# virtual/coreboot-private-files is deprecated. When adding a new board you
	# should add the coreboot-private-files-{board/chipset} ebuilds into the private
	# overlays, and avoid creating virtual packages.
	# See b/178642474
	IUSE="${IUSE} coreboot-private-files-board coreboot-private-files-chipset"

	# No pre-unibuild boards build firmware on ToT anymore. Assume
	# unibuild to keep ebuild clean.
	REQUIRED_USE="unibuild"

	# coreboot's build system handles stripping the binaries and producing a
	# separate .debug file with the symbols. This flag prevents portage from
	# stripping the .debug symbols
	RESTRICT="strip"

	DEPEND="
	coreboot-private-files-board? ( sys-boot/coreboot-private-files-board:= )
	coreboot-private-files-chipset? ( sys-boot/coreboot-private-files-chipset:= )
	virtual/coreboot-private-files
	bmpblk? ( sys-boot/chromeos-bmpblk:= )
	chipset_stoneyridge? ( sys-boot/amd-firmware:= )
	chipset_picasso? ( >=sys-boot/amd-picasso-fsp-0.0.2:= )
	chipset_cezanne? ( sys-boot/amd-cezanne-fsp:= )
	chromeos-base/chromeos-config:=
	"

	# While this package is never actually executed, we still need to specify
	# RDEPEND. A binary version of this package could exist that was built using an
	# outdated version of chromeos-config. Without the RDEPEND this stale binary
	# package is considered valid by the package manager. This is problematic
	# because we could have two binary packages installed having been build with
	# different versions of chromeos-config. By specifying the RDEPEND we force
	# the package manager to ensure the two versions use the same chromeos-config.
	RDEPEND="${DEPEND}"

	set_build_env() {
	local board="$1"

	CONFIG="$(cros-workon_get_build_dir)/${board}.config"
	CONFIG_SERIAL="$(cros-workon_get_build_dir)/${board}-serial.config"
	# Strip the .config suffix
	BUILD_DIR="${CONFIG%.config}"
	BUILD_DIR_SERIAL="${CONFIG_SERIAL%.config}"
	}

	# Create the coreboot configuration files for a particular board. This
	# creates a standard config and a serial config.
	# Args:
	# $1: board name
	# $2: libpayload build target (for config.baseboard files)
	create_config() {
	local board="$1"
	local base_board="$2"

	if [[ -s "${FILESDIR}/configs/config.${board}" ]]; then
	touch "${CONFIG}"

	if [[ -s "${FILESDIR}/configs/config.baseboard.${base_board}" ]]; then
	cat "${FILESDIR}/configs/config.baseboard.${base_board}" >> "${CONFIG}"
	# handle the case when "${CONFIG}" does not have a newline in the end.
	echo >> "${CONFIG}"
	fi

	cat "${FILESDIR}/configs/config.${board}" >> "${CONFIG}"

	# handle the case when "${CONFIG}" does not have a newline in the end.
	echo >> "${CONFIG}"

	# Override mainboard vendor if needed.
	if [[ -n "${SYSTEM_OEM}" ]]; then
	echo "CONFIG_MAINBOARD_VENDOR=\"${SYSTEM_OEM}\"" >> "${CONFIG}"
	fi
	if [[ -n "${SYSTEM_OEM_VENDOR_ID}" ]]; then
	echo "CONFIG_SUBSYSTEM_VENDOR_ID=${SYSTEM_OEM_VENDOR_ID}" >> "${CONFIG}"
	fi
	if [[ -n "${SYSTEM_OEM_DEVICE_ID}" ]]; then
	echo "CONFIG_SUBSYSTEM_DEVICE_ID=${SYSTEM_OEM_DEVICE_ID}" >> "${CONFIG}"
	fi
	if [[ -n "${SYSTEM_OEM_ACPI_ID}" ]]; then
	echo "CONFIG_ACPI_SUBSYSTEM_ID=\"${SYSTEM_OEM_ACPI_ID}\"" >> "${CONFIG}"
	fi

	# In case config comes from a symlink we are likely building
	# for an overlay not matching this config name. Enable adding
	# a CBFS based board ID for coreboot.
	if [[ -L "${FILESDIR}/configs/config.${board}" ]]; then
	echo "CONFIG_BOARD_ID_MANUAL=y" >> "${CONFIG}"
	echo "CONFIG_BOARD_ID_STRING=\"${BOARD_USE}\"" >> "${CONFIG}"
	fi
	else
	ewarn "Could not find existing config for ${board}."
	fi

	if use rmt; then
	echo "CONFIG_MRC_RMT=y" >> "${CONFIG}"
	fi
	if use vmx; then
	elog " - enabling VMX"
	echo "CONFIG_ENABLE_VMX=y" >> "${CONFIG}"
	fi
	if use quiet-cb; then
	# Suppress console spew if requested.
	cat >> "${CONFIG}" <<EOF
	CONFIG_DEFAULT_CONSOLE_LOGLEVEL=3
	# CONFIG_DEFAULT_CONSOLE_LOGLEVEL_8 is not set
	CONFIG_DEFAULT_CONSOLE_LOGLEVEL_3=y
	EOF
	fi
	if use mocktpm; then
	echo "CONFIG_VBOOT_MOCK_SECDATA=y" >> "${CONFIG}"
	fi
	if use mma; then
	echo "CONFIG_MMA=y" >> "${CONFIG}"
	fi

	# disable coreboot's own EC firmware building mechanism
	echo "CONFIG_EC_GOOGLE_CHROMEEC_FIRMWARE_NONE=y" >> "${CONFIG}"
	echo "CONFIG_EC_GOOGLE_CHROMEEC_PD_FIRMWARE_NONE=y" >> "${CONFIG}"
	# enable common GBB flags for development
	echo "CONFIG_GBB_FLAG_DEV_SCREEN_SHORT_DELAY=y" >> "${CONFIG}"
	echo "CONFIG_GBB_FLAG_DISABLE_FW_ROLLBACK_CHECK=y" >> "${CONFIG}"
	echo "CONFIG_GBB_FLAG_FORCE_DEV_BOOT_USB=y" >> "${CONFIG}"
	echo "CONFIG_GBB_FLAG_FORCE_DEV_SWITCH_ON=y" >> "${CONFIG}"
	local version=$(${CHROOT_SOURCE_ROOT}/src/third_party/chromiumos-overlay/chromeos/config/chromeos_version.sh \|grep "^[[:space:]]*CHROMEOS_VERSION_STRING=" \|cut -d= -f2)
	echo "CONFIG_VBOOT_FWID_VERSION=\".${version}\"" >> "${CONFIG}"
	if use em100-mode; then
	einfo "Enabling em100 mode via CONFIG_EM100 (slower SPI flash)"
	echo "CONFIG_EM100=y" >> "${CONFIG}"
	fi
	# Use FSP's GOP in favor of coreboot's Ada based Intel graphics init
	# which we don't include at this time. A no-op on non-FSP/GOP devices.
	echo "CONFIG_RUN_FSP_GOP=y" >> "${CONFIG}"

	cp "${CONFIG}" "${CONFIG_SERIAL}"
	file="${FILESDIR}/configs/fwserial.${board}"
	if [ ! -f "${file}" ] && [ -n "${base_board}" ]; then
	file="${FILESDIR}/configs/fwserial.${base_board}"
	fi
	if [ ! -f "${file}" ]; then
	file="${FILESDIR}/configs/fwserial.default"
	fi
	cat "${file}" >> "${CONFIG_SERIAL}" \|\| die
	# handle the case when "${CONFIG_SERIAL}" does not have a newline in the end.
	echo >> "${CONFIG_SERIAL}"

	# Check that we're using coreboot-sdk
	if ! use coreboot-sdk; then
	die "Enable coreboot-sdk to build coreboot."
	fi
	if grep -q "^CONFIG_ANY_TOOLCHAIN=y" "${CONFIG}"; then
	die "Drop ANY_TOOLCHAIN from ${CONFIG}: we don't support it anymore."
	fi

	einfo "Configured ${CONFIG} for board ${board} in ${BUILD_DIR}"
	}

	src_prepare() {
	local froot="${SYSROOT}/firmware"
	local privdir="${SYSROOT}/firmware/coreboot-private"
	local file

	default

	export GENERIC_COMPILER_PREFIX="invalid"

	mkdir "$(cros-workon_get_build_dir)"

	if [[ -d "${privdir}" ]]; then
	while read -d $'\0' -r file; do
	rsync --recursive --links --executability \
	"${file}" ./ \|\| die
	done < <(find "${privdir}" -maxdepth 1 -mindepth 1 -print0)
	fi

	cp -a "${FILESDIR}/3rdparty/"* 3rdparty

	local name
	local coreboot
	local libpayload
	while read -r name; do
	read -r coreboot
	read -r libpayload
	set_build_env "${coreboot}"
	create_config "${coreboot}" "${libpayload}"
	done < <(cros_config_host "get-firmware-build-combinations" \
	coreboot,libpayload \|\| die)
	}

	add_fw_blob() {
	local rom="$1"
	local cbname="$2"
	local blob="$3"
	local cbhash="${cbname%.bin}.hash"
	local hash="${blob%.bin}.hash"

	cbfstool "${rom}" add -r FW_MAIN_A,FW_MAIN_B -t raw -c lzma \
	-f "${blob}" -n "${cbname}" \|\| die
	cbfstool "${rom}" add -r FW_MAIN_A,FW_MAIN_B -t raw -c none \
	-f "${hash}" -n "${cbhash}" \|\| die
	}

	# Build coreboot with a supplied configuration and output directory.
	# $1: Build directory to use (e.g. "build_serial")
	# $2: Config file to use (e.g. ".config_serial")
	# $3: Build target build (e.g. "pyro")
	make_coreboot() {
	local builddir="$1"
	local config_fname="$2"

	rm -rf "${builddir}" .xcompile

	local CB_OPTS=(
	obj="${builddir}"
	DOTCONFIG="${config_fname}"
	HOSTCC="$(tc-getBUILD_CC)"
	HOSTCXX="$(tc-getBUILD_CXX)"
	HOSTPKGCONFIG="$(tc-getBUILD_PKG_CONFIG)"
	)
	use quiet && CB_OPTS+=( "V=0" )
	use verbose && CB_OPTS+=( "V=1" )
	use quiet && REDIR="/dev/null" \|\| REDIR="/dev/stdout"

	# Configure and build coreboot.
	yes "" \| emake oldconfig "${CB_OPTS[@]}" >${REDIR}
	emake "${CB_OPTS[@]}"

	# Expand FW_MAIN_* since we might add some files
	cbfstool "${builddir}/coreboot.rom" expand -r FW_MAIN_A,FW_MAIN_B

	# Modify firmware descriptor if building for the EM100 emulator on
	# Intel platforms.
	# TODO(crbug.com/863396): Should we have an 'intel' USE flag? Do we
	# still have any Intel platforms that don't use ifdtool?
	if ! use amd_cpu && use em100-mode; then
	einfo "Enabling em100 mode via ifdttool (slower SPI flash)"
	ifdtool --em100 "${builddir}/coreboot.rom" \|\| die
	mv "${builddir}/coreboot.rom"{.new,} \|\| die
	fi
	}

	# Add fw blobs to the coreboot.rom.
	# $1: Build directory to use (e.g. "build_serial")
	# $2: Build target build (e.g. "pyro")
	add_fw_blobs() {
	local builddir="$1"
	local build_target="$2"
	local froot="${SYSROOT}/firmware/${build_target}"
	local fblobroot="${SYSROOT}/firmware"

	local blob
	local cbname
	for blob in ${FW_BLOBS}; do
	local blobfile="${fblobroot}/${blob}"

	# Use per-board blob if available
	if [[ -e "${froot}/${blob}" ]]; then
	blobfile="${froot}/${blob}"
	fi

	cbname=$(basename "${blob}")
	add_fw_blob "${builddir}/coreboot.rom" "${cbname}" \
	"${blobfile}" \|\| die
	done

	if [ -d ${froot}/cbfs ]; then
	die "something is still using ${froot}/cbfs, which is deprecated."
	fi
	}

	src_compile() {
	# Set KERNELREVISION (really coreboot revision) to the ebuild revision
	# number followed by a dot and the first seven characters of the git
	# hash. The name is confusing but consistent with the coreboot
	# Makefile.
	local sha1v="${VCSID/*-/}"
	export KERNELREVISION=".${PV}.${sha1v:0:7}"

	if ! use coreboot-sdk; then
	tc-export CC
	# Export the known cross compilers so there isn't a reliance
	# on what the default profile is for exporting a compiler. The
	# reasoning is that the firmware may need more than one to build
	# and boot.
	export CROSS_COMPILE_x86="i686-pc-linux-gnu-"
	export CROSS_COMPILE_mipsel="mipsel-cros-linux-gnu-"
	export CROSS_COMPILE_arm64="aarch64-cros-linux-gnu-"
	export CROSS_COMPILE_arm="armv7a-cros-linux-gnu- armv7a-cros-linux-gnueabihf-"
	else
	export CROSS_COMPILE_x86=${COREBOOT_SDK_PREFIX_x86_32}
	export CROSS_COMPILE_mipsel=${COREBOOT_SDK_PREFIX_mips}
	export CROSS_COMPILE_arm64=${COREBOOT_SDK_PREFIX_arm64}
	export CROSS_COMPILE_arm=${COREBOOT_SDK_PREFIX_arm}

	export PATH=/opt/coreboot-sdk/bin:$PATH
	fi

	use verbose && elog "Toolchain:\n$(sh util/xcompile/xcompile)\n"

	while read -r name; do
	read -r coreboot

	set_build_env "${coreboot}"
	make_coreboot "${BUILD_DIR}" "${CONFIG}"
	add_fw_blobs "${BUILD_DIR}" "${coreboot}"

	# Build a second ROM with serial support for developers.
	make_coreboot "${BUILD_DIR_SERIAL}" "${CONFIG_SERIAL}"
	add_fw_blobs "${BUILD_DIR_SERIAL}" "${coreboot}"
	done < <(cros_config_host "get-firmware-build-combinations" coreboot \|\| die)
	}

	# Install files into /firmware
	# Args:
	# $1: The build combination name
	# $2: The coreboot build target
	do_install() {
	local build_combination="$1"
	local build_target="$2"
	local dest_dir="/firmware"
	local mapfile

	if [[ -n "${build_target}" ]]; then
	dest_dir+="/${build_target}"
	einfo "Installing coreboot ${build_target} into ${dest_dir}"
	fi
	insinto "${dest_dir}"

	newins "${BUILD_DIR}/coreboot.rom" coreboot.rom
	newins "${BUILD_DIR_SERIAL}/coreboot.rom" coreboot.rom.serial

	OPROM=$( awk 'BEGIN{FS="\""} /CONFIG_VGA_BIOS_FILE=/ { print $2 }' \
	"${CONFIG}" )
	CBFSOPROM=pci$( awk 'BEGIN{FS="\""} /CONFIG_VGA_BIOS_ID=/ { print $2 }' \
	"${CONFIG}" ).rom
	FSP=$( awk 'BEGIN{FS="\""} /CONFIG_FSP_FILE=/ { print $2 }' \
	"${CONFIG}" )
	if [[ -n "${FSP}" ]]; then
	newins ${FSP} fsp.bin
	fi
	# Save the psp_verstage binary for signing on AMD Fam17h platforms
	if [[ -e "${BUILD_DIR}/psp_verstage.bin" ]]; then
	newins "${BUILD_DIR}/psp_verstage.bin" psp_verstage.bin
	fi
	if [[ -n "${OPROM}" ]]; then
	newins ${OPROM} ${CBFSOPROM}
	fi
	if use memmaps; then
	for mapfile in "${BUILD_DIR}"/cbfs/fallback/*.map
	do
	doins $mapfile
	done
	fi
	newins "${CONFIG}" coreboot.config
	newins "${CONFIG_SERIAL}" coreboot_serial.config

	# Keep binaries with debug symbols around for crash dump analysis
	if [[ -s "${BUILD_DIR}/bl31.elf" ]]; then
	newins "${BUILD_DIR}/bl31.elf" bl31.elf
	newins "${BUILD_DIR_SERIAL}/bl31.elf" bl31.serial.elf
	fi
	insinto "${dest_dir}"/coreboot
	doins "${BUILD_DIR}"/cbfs/fallback/*.debug
	nonfatal doins "${BUILD_DIR}"/cbfs/fallback/bootblock.bin
	insinto "${dest_dir}"/coreboot_serial
	doins "${BUILD_DIR_SERIAL}"/cbfs/fallback/*.debug
	nonfatal doins "${BUILD_DIR_SERIAL}"/cbfs/fallback/bootblock.bin

	# coreboot's static_fw_config.h is copied into libpayload include
	# directory.
	insinto "/firmware/${build_combination}/libpayload/libpayload/include"
	doins "${BUILD_DIR}/static_fw_config.h"
	einfo "Installed static_fw_config.h into libpayload include directory"
	}

	src_install() {
	while read -r name; do
	read -r coreboot

	set_build_env "${coreboot}"
	do_install "${name}" "${coreboot}"
	done < <(cros_config_host "get-firmware-build-combinations" coreboot \|\| die)
	}