# Copyright 1999-2026 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8

inherit savedconfig toolchain-funcs

DESCRIPTION="Locally built Linux 2.6.39.4 kernel with Gentoo legacy patches and seccomp filter"
HOMEPAGE="https://www.kernel.org"
SRC_URI="https://www.kernel.org/pub/linux/kernel/v2.6/linux-${PV}.tar.xz"
S="${WORKDIR}/linux-${PV}"

LICENSE="GPL-2"
SLOT="${PV}"
KEYWORDS="-* ~amd64 ~x86"

BDEPEND="
	app-alternatives/bc
	app-alternatives/lex
	app-alternatives/yacc
	dev-lang/perl
"

PATCHES=(
	"${FILESDIR}/linux-2.6.39.4-seccomp-filter-backport.patch"
	"${FILESDIR}/linux-2.6.39.4-gcc15-build-fixes.patch"
	"${FILESDIR}/linux-2.6.39.4-gentoo-3.2-compat.patch"
)

QA_FLAGS_IGNORED="
	usr/src/linux-.*/scripts/.*
	usr/src/linux-.*/vmlinux
"

_kernel_make() {
	emake ARCH="$(tc-arch-kernel)" "$@"
}

_default_config() {
	case "$(tc-arch)" in
		amd64)
			cp "${FILESDIR}/default-amd64.config" .config || die
			;;
		x86)
			cp "${FILESDIR}/default-x86.config" .config || die
			;;
		*)
			die "${PN} only supports amd64 and x86"
			;;
	esac
}

_force_config() {
	scripts/config \
		--set-str LOCALVERSION "-gentoo" \
		--disable LOCALVERSION_AUTO \
		--enable MODULES \
		--enable MODULE_UNLOAD \
		--enable SECCOMP \
		--enable SECCOMP_FILTER \
		--enable IKCONFIG \
		--enable IKCONFIG_PROC \
		--enable DEVTMPFS \
		--enable TMPFS || die
}

src_prepare() {
	default
	eapply_user
}

src_configure() {
	_default_config
	restore_config .config
	_force_config
	_kernel_make oldnoconfig
}

src_compile() {
	_kernel_make bzImage modules
}

src_install() {
	local kv_full
	kv_full="$(_kernel_make -s kernelrelease)" || die

	_kernel_make INSTALL_MOD_PATH="${D}" modules_install

	rm -f "${D}/lib/modules/${kv_full}"/{build,source} || die
	dosym "../../../usr/src/linux-${kv_full}" "/lib/modules/${kv_full}/build"
	dosym "../../../usr/src/linux-${kv_full}" "/lib/modules/${kv_full}/source"

	insinto /boot
	newins arch/x86/boot/bzImage "vmlinuz-${kv_full}"
	newins System.map "System.map-${kv_full}"
	newins .config "config-${kv_full}"

	dodir /usr/src
	cp -a "${S}" "${D}/usr/src/linux-${kv_full}" || die
	echo "${CATEGORY}/${PF}:${SLOT}" > "${D}/usr/src/linux-${kv_full}/dist-kernel" || die

	use savedconfig && save_config .config
}

pkg_postinst() {
	local kv_full="${PV}-gentoo"

	if type -P depmod >/dev/null; then
		depmod -a "${kv_full}" || ewarn "depmod failed for ${kv_full}"
	fi

	elog "Installed kernel image: /boot/vmlinuz-${kv_full}"
	elog "Installed build tree: /usr/src/linux-${kv_full}"
}