# Copyright 1999-2013 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

EAPI=5
ETYPE="sources"

inherit savedconfig kernel-2
detect_version

SLOT="${PV%.*}"

DESCRIPTION="Kernel stable sources and build"
HOMEPAGE="http://www.kernel.org"
SRC_URI="${KERNEL_URI} ${GENPATCHES_URI} ${ARCH_URI}"

KEYWORDS="~amd64 ~x86"

SRCDIR="${WORKDIR}/linux-${KV_FULL}"
BUILDDIR="${WORKDIR}/build"

KV_EXTRA="${EXTRAVERSION}"
S="${SRCDIR}"

IUSE="build source zlib lzma"
REQUIRED_USE="
	?? ( zlib lzma )
	zlib? ( build )
	lzma? ( build )
	symlink? ( source )
	"

DEPEND="
	|| (
			sys-apps/kmod[zlib?,lzma?]
			sys-apps/module-init-tools
	   )"

configval ()
{
	local _v="CONFIG_$1"

	# Export only the needed config value
	# when not already define
	declare -p ${_v} > /dev/null 2>&1 \
		|| . <(sed -n "/^${_v}=/ p" ${BUILDDIR}/.config)

	case "${!_v}" in
		"") declare "$_v=n" ; export $_v ; return 1 ;;
		*)                    export $_v ; return 0 ;;
	esac
}

do_prepare_build ()
{
	mkdir "${BUILDDIR}"

	restore_config "${BUILDDIR}/.config"
	if [ ! -e "${BUILDDIR}/.config" ] ; then
		ewarn "Generate .config using 'defconfig'"
		emake defconfig "${myopt[@]}"
	fi

	mkdir "${WORKDIR}/boot"

	if configval CMDLINE_BOOL && configval CMDLINE ; then
		einfo "Creating kernel.arg"
		einfo "  CONFIG_CMDLINE='${CONFIG_CMDLINE}'"
		echo "${CONFIG_CMDLINE}" > "${WORKDIR}/boot/kernel.arg"
	fi

	configval MODULES || ewarn "CONFIG_MODULES is not set"
}

src_prepare ()
{
	bopt=(
		-C "${BUILDDIR}"
		-f "${SRCDIR}/Makefile"
		KBUILD_SRC="${SRCDIR}"
		KCONFIG_CONFIG="${BUILDDIR}/.config"

		KBUILD_BUILD_USER="${KBUILD_BUILD_USER:-$PORTAGE_USERNAME}"
	)

	copt=(
		CC=$(tc-getCC) HOSTCC=${CBUILD}-gcc CROSS_COMPILE=${CHOST}-
		ARCH=$(tc-arch-kernel) SUBARCH=$(tc-arch-kernel)
	)

	vopt=(
		EXTRAVERSION="${KV_EXTRA}"
		LOCALVERSION= CONFIG_LOCALVERSION=
	)

	myopt=( "${bopt[@]}" "${copt[@]}" "${vopt[@]}" )

	use build && do_prepare_build
}

do_compile_build ()
{
	einfo "Checking configuration file"
	emake oldconfig "${myopt[@]}" < /dev/null

	if diff -Nu0 ${BUILDDIR}/.config.old ${BUILDDIR}/.config \
		| egrep -q '^(\-|\+)CONFIG_' ; then
		eerror "You configuration is not up to date"
		diff -Nu ${BUILDDIR}/.config.old ${BUILDDIR}/.config
		die "Bad configuration"
	fi

	einfo "Building kernel"
	emake bzImage "${myopt[@]}"

	if configval MODULES ; then
		einfo "Building modules"
		emake modules "${myopt[@]}"
	fi
}

src_compile ()
{
	use build && do_compile_build
}

do_install_sources ()
{
	kernel-2_src_install
}

do_install_build ()
{
	einfo "Installing kernel"
	emake install "${myopt[@]}" \
		INSTALL_PATH="${WORKDIR}/boot"

	insinto /boot/${KV_FULL}

	newins "${WORKDIR}/boot/config-${KV_FULL}"     kernel.cfg
	newins "${WORKDIR}/boot/vmlinuz-${KV_FULL}"    kernel.img
	newins "${WORKDIR}/boot/System.map-${KV_FULL}" System.map

	if configval CMDLINE_BOOL && configval CMDLINE ; then
		doins "${WORKDIR}/boot/kernel.arg"
	fi

	if configval MODULES ; then
		einfo "Installing modules"
		emake modules_install "${myopt[@]}" \
			INSTALL_MOD_PATH="${WORKDIR}" \
			INSTALL_MOD_STRIP="${PORTAGE_STRIP_FLAGS}"

		# kmod only support zlib and lzma
		# See libkmod/libkmod-util.c / struct kmod_ext kmod_exts
		if use zlib || use lzma ; then
			use zlib && { cmp="gzip -9c" ; ext="gz" ; }
			use lzma && { cmp="xz -9c"   ; ext="xz" ; }

			einfo "Compressing modules"
			find "${WORKDIR}/lib/modules" \
				-type f -name "*.ko" \
				| while read ; do
					$cmp < $REPLY > ${REPLY}.${ext}
					rm $REPLY
				done
		fi

		einfo "Generating modules.dep"
		depmod -ae -F "${BUILDDIR}/System.map" -b "${WORKDIR}" "${KV_FULL}" \
			|| die "depmod failed"

		rm "${WORKDIR}/lib/modules/${KV_FULL}/build"
		rm "${WORKDIR}/lib/modules/${KV_FULL}/source"

		insinto /lib
		doins -r "${WORKDIR}/lib/modules"

		# No need to make firmware_install, make modules_install does
		if [ -e "${WORKDIR}/lib/firmware" ] ; then
			einfo "Installing firmwares"

			insinto /lib
			doins -r "${WORKDIR}/lib/firmware"
		fi
	fi
}

src_install ()
{
	use build && do_install_build
	use source && do_install_sources
	use savedconfig && save_config "${BUILDDIR}/.config"
}

pkg_postinst ()
{
	kernel-2_pkg_postinst

	einfo "You may need to:"
	einfo "  make menuconfig ${copt[@]}"
}