kernel_install

#!/bin/sh

set -eu

alias make="make --jobs=$(nproc)"

silent() {
	"${@}" >/dev/null 2>/dev/null
}

efibootmgr_add() {
	local kernel="${1}"
	local label="${2}"

	if ! efibootmgr | grep -qE "${label}$"
	then
		silent efibootmgr -c -l "${kernel}" -L "${label}"
	fi
}

boot_mounted=false
if ! mount | grep -q '/boot'
then
	mount /boot
	boot_mounted=true
fi

make
if grep -q 'CONFIG_MODULES=y' .config
then
	make modules_install
fi
install_out="$(make install)"

kernel_ext="$(echo "${install_out}" | cut -d ' ' -f 3)"
kernel_version="$(echo "${kernel_ext}" | cut -d '-' -f 1)"
kernel_tag="$(echo "${kernel_ext}" | cut -d '-' -f 2)"
kernel_revision="$(echo "${kernel_ext}" | cut -d '-' -f 3)"
[ -n "${kernel_revision}" ] && kernel_version="${kernel_version}-${kernel_revision}"

boot_name="Gentoo ${kernel_version}"
[ "${kernel_tag}" != 'gentoo' ] && boot_name="${boot_name} ${kernel_tag}"

efi_ro=false
if mount | grep "^efivarfs" | grep -q "ro"
then
	efi_ro=true
	efi_mpoint=$(mount | grep "^efivarfs" | cut -d " " -f 3)
	mount -o remount,rw efivarfs $efi_mpoint
fi

efibootmgr_add "\\vmlinuz-${kernel_ext}.old" "${boot_name} old"
efibootmgr_add "\\vmlinuz-${kernel_ext}" "${boot_name}"

if ${efi_ro}
then
	mount -o remount,ro efivarfs $efi_mpoint
fi

if ${boot_mounted}
then
	umount /boot
fi