makeefi

#!/bin/bash
# v1.0

# Copyright (c) 2019, 2020 Jyrki Launonen
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# -- Config --
EFI="/mnt/efi"
MAKEOPTS="-j8"

# -- End of config --


# Some simple help.
if [ -z "$1" -o "$1" = "--help" ]; then
	echo "$0 0"
	echo "$0 [1] [2] [3]"
	echo " 0 : Only show parsed kernel version (useful to check the parsing is not broken)."
	echo " 1 : Make and patch initramfs with gpg."
	echo " 2 : Patch (INITRAMFS_SOURCE) kernel config, make kernel and install modules."
	echo " 3 : Install built kernel to EFI USB stick."
	exit 1
fi

set -eu

# Parse kernel main version.
CUR=$(readlink -f .)
if [ "${CUR#/usr/src/}" = "${CUR}" ]; then
	echo "This must be run in the kernel source directory, usually /usr/src/linux"
	exit 1
fi
THIS=$(basename "${CUR}" | cut -f 2 -d -)

echo "Kernel version: $THIS"

if [ "$1" = "0" ]; then
	exit 0
fi

# Ensure we can do what we need.
if [ "$(id -u)" -ne 0 ]; then
	echo "This must be run as root."
	exit 1
fi

set -x

pt1() {
	make ${MAKEOPTS} modules
	genkernel --no-install --no-mountboot --luks --lvm --no-gpg --udev --busybox --no-compress-initramfs --all-ramdisk-modules --firmware --no-postclear initramfs

	mkdir -p /tmp/initrd
	cd /tmp/initrd/
	cp -v /var/tmp/genkernel/initramfs-${THIS}-gentoo .

	tar -xf /usr/portage/packages/app-crypt/gnupg-1.4*.tbz2 ./usr/bin/gpg
	echo usr/bin/gpg | cpio -H newc -o --append -F initramfs-*
	mv initramfs-${THIS}-gentoo{,.cpio}
	mv initramfs-*.cpio /var/tmp/genkernel/
	cd -
}

pt2() {
	sed -i -e 's|^CONFIG_INITRAMFS_SOURCE=.*$|CONFIG_INITRAMFS_SOURCE="/var/tmp/genkernel/initramfs-'${THIS}'-gentoo.cpio"|;' .config
	make ${MAKEOPTS} && make modules_install
}

pt3() {
	local MOUNTED=""
	if findmnt "${EFI}" >/dev/null; then MOUNTED=1; fi

	[[ -z "${MOUNTED}" ]] && mount "${EFI}"
	if [ -e "${EFI}/EFI/Boot/bootx86.efi" ]; then
		mv "${EFI}"/EFI/Boot/bootx86{.efi,-old.efi}
	fi
	cp -aLvn arch/x86_64/boot/bzImage "${EFI}"/EFI/Boot/bootx86.efi
	sync
	ls -l "${EFI}"/EFI/Boot/
	[[ -z "${MOUNTED}" ]] && umount "${EFI}"
}


if [ "$1" = "1" ]; then
	pt1
	shift
fi
if [ "$1" = "2" ]; then
	pt2
	shift
fi
if [ "$1" = "3" ]; then
	pt3
	shift
fi