# Maintainer: Natanael Copa <ncopa@alpinelinux.org>

_flavor=rm
pkgname=linux-${_flavor}
pkgver=5.4.70
_rmver=1.3.3
pkgrel=0
pkgdesc="Linux kernel for remarkable tablet 1 and 2"
url="https://www.kernel.org"
depends="mkinitfs"
_depends_dev="perl gmp-dev elfutils-dev bash flex bison"
makedepends="$_depends_dev sed installkernel bc linux-headers linux-firmware-any openssl-dev
	diffutils"
options="!strip"
_config=${config:-config-lts.${CARCH}}
install=
source="
	https://github.com/reMarkable/linux/archive/refs/tags/RM1XX_${pkgver}_v$_rmver.tar.gz
	enable-sdhc1.patch"
subpackages="$pkgname-dev:_dev:$CBUILD_ARCH"
builddir="$srcdir"/linux-RM1XX_${pkgver}_v$_rmver
_flavors=

arch="armv7"
license="GPL-2.0"

_carch=${CARCH}
case "$_carch" in
aarch64*) _carch="arm64" ;;
arm*) _carch="arm" ;;
mips*) _carch="mips" ;;
ppc*) _carch="powerpc" ;;
s390*) _carch="s390" ;;
esac

prepare() {
	make zero-gravitas_defconfig
}

build() {
	unset LDFLAGS
	export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"
	for i in $_flavors; do
		cd "$srcdir"/build-$i.$CARCH
		make ARCH="$_carch" CC="${CC:-gcc}" \
			KBUILD_BUILD_VERSION="$((pkgrel + 1 ))-Alpine"
	done
}

_package() {
	local _buildflavor="$1" _outdir="$2"
	local _abi_release=${pkgver}-${pkgrel}-${_buildflavor}
	export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"

	cd "$srcdir"/build-$_buildflavor.$CARCH
	# modules_install seems to regenerate a defect Modules.symvers on s390x. Work
	# around it by backing it up and restore it after modules_install
	cp Module.symvers Module.symvers.backup

	mkdir -p "$_outdir"/boot "$_outdir"/lib/modules

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

	make -j1 modules_install $_install \
		ARCH="$_carch" \
		INSTALL_MOD_PATH="$_outdir" \
		INSTALL_PATH="$_outdir"/boot \
		INSTALL_DTBS_PATH="$_outdir/boot/dtbs-$_flavor"

	cp Module.symvers.backup Module.symvers

	rm -f "$_outdir"/lib/modules/${_abi_release}/build \
		"$_outdir"/lib/modules/${_abi_release}/source
	rm -rf "$_outdir"/lib/firmware

	install -D include/config/kernel.release \
		"$_outdir"/usr/share/kernel/$_buildflavor/kernel.release
}

# main flavor installs in $pkgdir
package() {
	depends="$depends linux-firmware-any"

	_package lts "$pkgdir"
}

# subflavors install in $subpkgdir
virt() {
	_package virt "$subpkgdir"
}

_dev() {
	local _flavor=$(echo $subpkgname | sed -E 's/(^linux-|-dev$)//g')
	local _abi_release=${pkgver}-${pkgrel}-$_flavor
	# 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 $_flavor kernel"
	depends="$_depends_dev"
	local dir="$subpkgdir"/usr/src/linux-headers-${_abi_release}
	export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"

	# first we import config, run prepare to set up for building
	# external modules, and create the scripts
	mkdir -p "$dir"
	cp "$srcdir"/config-$_flavor.${CARCH} "$dir"/.config
	echo "-$pkgrel-$_flavor" > "$dir"/localversion-alpine

	make -j1 -C "$srcdir"/linux-$_kernver O="$dir" ARCH="$_carch" \
		syncconfig prepare modules_prepare scripts

	# 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 "$srcdir"/linux-$_kernver
	find .  -path './include/*' -prune \
		-o -path './scripts/*' -prune -o -type f \
		\( -name 'Makefile*' -o -name 'Kconfig*' -o -name 'Kbuild*' -o \
		   -name '*.sh' -o -name '*.pl' -o -name '*.lds' -o -name 'Platform' \) \
		-print | cpio -pdm "$dir"

	cp -a scripts include "$dir"

	find $(find arch -name include -type d -print) -type f \
		| cpio -pdm "$dir"

	install -Dm644 "$srcdir"/build-$_flavor.$CARCH/Module.symvers \
		"$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="
80ab274ca3d30935d9913490662f17499c1ceedb438fe171554097d25ffc1cf85ee53f0c1642e94c0b833fdfb17636cd554bf685e4a6f5dac20cf122c1a25447  RM1XX_5.4.70_v1.3.3.tar.gz
6f2036a2f88b0d80ba5e37e3d119aebd2dc33453f5a5d84b319ec50c0c00d8cb93fc4b3f5e10f3d56c1496f3cb297551c405f36c5d864af112398f0792f1549a  enable-sdhc1.patch
"