_flavor=postmarketos-mainline
_config="config-${_flavor}.${CARCH}"

pkgname=linux-${_flavor}

pkgver=4.18
_pkgver=${pkgver/_/-}
_kernver=${pkgver%_rc*}
_mainver=${_kernver%.*}
_patchlevel=${_kernver/$_mainver./}
_basever=${_mainver}.$((_patchlevel-1))
pkgrel=3

arch="x86_64 armhf aarch64"
pkgdesc="Linux for pmOS supported chipsets (mainline, more bleeding-edge than stable)"
url="https://kernel.org/"
depends=""
makedepends="perl sed installkernel bash gmp-dev bc linux-headers elfutils-dev openssl-dev file bison flex"
options="!strip !check !tracedeps"
install=
source="
	https://cdn.kernel.org/pub/linux/kernel/v$_mainver.x/linux-$_basever.tar.xz
	linux-v$_basever-v$_pkgver.patch::https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/rawdiff/?id=v$_pkgver&id2=v$_basever
	config-${_flavor}.armhf
	config-${_flavor}.aarch64
	config-${_flavor}.x86_64
"

subpackages="$pkgname-dev"

license="GPL2"
_abi_release=$_pkgver
_carch=${CARCH}
case "$_carch" in
aarch64*) _carch="arm64" ;;
arm*) _carch="arm" ;;
ppc*) _carch="powerpc" ;;
s390*) _carch="s390" ;;
esac

HOSTCC="${CC:-gcc}"
HOSTCC="${HOSTCC#${CROSS_COMPILE}}"

builddir="$srcdir/linux-$_basever"

prepare() {
	local _patch_failed=
	cd "$builddir"
	# first apply patches in specified order
	for i in $source; do
		case $i in
		*.patch|*.patch::*)
			_patch=${i%::*}
			msg "Applying $_patch..."
			if ! patch -s -p1 -N -i "$srcdir"/$_patch; then
				echo $_patch >>failed
				_patch_failed=1
			fi
			;;
		esac
	done

	if ! [ -z "$_patch_failed" ]; then
		error "The following patches failed:"
		cat failed
		return 1
	fi

	mkdir -p "$srcdir"/build
	cp -v "$srcdir"/$_config "$srcdir"/build/.config
	make -C "$builddir" O="$srcdir"/build ARCH="$_carch" HOSTCC="$HOSTCC" \
		olddefconfig
}

build() {
	cd "$srcdir"/build
	unset LDFLAGS
	make ARCH="$_carch" CC="${CC:-gcc}" \
		KBUILD_BUILD_VERSION="$((pkgrel + 1 ))-${_flavor}" \
		CFLAGS_MODULE=-fno-pic
}

package() {
	cd "$srcdir/build/arch/${_carch}/boot"

	if [ "$CARCH" == "aarch64" ]; then
		install -Dm644 "$srcdir/build/arch/${_carch}/boot/Image" \
			"$pkgdir/boot/vmlinuz-$_flavor"
	else
		install -Dm644 "$srcdir/build/arch/${_carch}/boot/"*zImage \
			"$pkgdir/boot/vmlinuz-$_flavor"
	fi

	install -D "$srcdir/build/include/config/kernel.release" \
		"$pkgdir/usr/share/kernel/$_flavor/kernel.release"

	cd "$srcdir"/build

	local _install
	case "$CARCH" in
	aarch64*|arm*)	_install="modules_install dtbs_install" ;;
	*)		_install="modules_install" ;;
	esac

	make -j1 $_install \
		ARCH="$_carch" \
		INSTALL_MOD_PATH="$pkgdir" \
		INSTALL_DTBS_PATH="$pkgdir/usr/share/dtb"
}


dev() {
	# copy the only the parts that we really need for build 3rd party
	# kernel modules and install those as /usr/src/linux-headers,
	# simlar to what ubuntu does
	#
	# this way you dont need to install the 300-400 kernel sources to
	# build a tiny kernel module
	#
	pkgdesc="Headers and script for third party modules for postmarketos kernel"
	depends="gmp-dev bash perl"
	local dir="$subpkgdir"/usr/src/linux-headers-${_abi_release}

	# first we import config, run prepare to set up for building
	# external modules, and create the scripts
	mkdir -p "$dir"
	cp "$srcdir"/$_config "$dir"/.config
	make -j1 -C "$builddir" O="$dir" ARCH="$_carch" HOSTCC="$HOSTCC" \
		olddefconfig prepare modules_prepare scripts

	# needed for 3rd party modules
	# https://bugzilla.kernel.org/show_bug.cgi?id=11143
	case "$CARCH" in
	ppc*) (cd "$dir" && make arch/powerpc/lib/crtsavres.o);;
	esac

	# remove the stuff that points to real sources. we want 3rd party
	# modules to believe this is the soruces
	rm "$dir"/Makefile "$dir"/source

	# copy the needed stuff from real sources
	#
	# this is taken from ubuntu kernel build script
	# http://kernel.ubuntu.com/git/ubuntu/ubuntu-zesty.git/tree/debian/rules.d/3-binary-indep.mk

	cd "$builddir"
	find . -path './include/*' -prune \
		-o -path './scripts/*' -prune -o -type f \
		\( -name 'Makefile*' -o -name 'Kconfig*' -o -name 'Kbuild*' -o \
		   -name '*.sh' -o -name '*.pl' -o -name '*.lds' \) \
		-print | cpio -pdm "$dir"
	cp -a scripts include "$dir"
	find $(find arch -name include -type d -print) -type f \
		| cpio -pdm "$dir"

	install -Dm644 "$srcdir"/build/Module.symvers \
		"$dir"/Module.symvers

	mkdir -p "$subpkgdir"/lib/modules/${_abi_release}
	ln -sf /usr/src/linux-headers-${_abi_release} \
		"$subpkgdir"/lib/modules/${_abi_release}/build
}
sha512sums="4d9de340a26155a89ea8773131c76220cc2057f2b5d031b467b60e8b14c1842518e2d60a863d8c695f0f7640f3f18d43826201984a238dade857b6cef79837db  linux-4.17.tar.xz
da3d10fd0206e006e0d4448624cb0d5de61dce1e80dcc5272b088fa7284d360e5bac464a369bbf5d06625fc20d73991ee81f09bb1c8c271eb45646d3ce7927e7  linux-v4.17-v4.18.patch
581d889683f64fc8d9b31d1f87dc75b7b4f466a17b486ba2cb280b7cfa56003dd7c2e876e02c7e4395b8df28164b1efa4281670fb33aa814c2fa92b36ddfecf8  config-postmarketos-mainline.armhf
2257ce6abd1596e46b69cd8622785fdc8bd2e6b5d6448520b45c3d5151e839fd1f0ad31d673a3ee6984db9792cc5a70226e6f6a13be16e0d2e064e8ae200c681  config-postmarketos-mainline.aarch64
34e818059bd94b0431f986d7cb63fa779fe2aaa6c2199a054bd6f56a3df037555e80f20eeb78ac2dde5a517fd7dd7385e8be15aa6280685ee02129119638bdea  config-postmarketos-mainline.x86_64"