Check if kernel actually exists

[people/arne_f/kernel-updater.git] / src / kernel-updater.in

#!/bin/bash
###############################################################################
#                                                                             #
# firmware-update - IPFire Firmware Update Tool                               #
# Copyright (C) 2019 IPFire Development Team                                  #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

PACKAGE_NAME="@PACKAGE_NAME@"
PACKAGE_VERSION="@PACKAGE_VERSION@"

GRUB_CFG="/boot/grub/grub.cfg"
MODULES_PATH="/lib/modules"

RUNNING_VERSION="$(uname -r)"

update_bootloader() {
	# GRUB
	if [ -e "${GRUB_CFG}" ]; then
		grub-mkconfig -o "${GRUB_CFG}" || return $?
	fi

	return 0
}

# This function installs a new kernel
do_install() {
	local version="${1}"

	# Check if we actually have a kernel with this version
	if ! check_version "${version}"; then
		echo "Kernel ${version} does not exist" >&2
		return 2
	fi

	# Update module dependencies
	echo "Updating module dependencies..."
	if ! depmod -A "${version}"; then
		echo "Could not update module dependencies. Exiting." >&2
		return 1
	fi

	# Generate initramfs
	echo "Generating initramfs..."
	if ! dracut --quiet --force --early-microcode --xz \
			"/boot/initramfs-${version}.img" "${version}"; then
		echo "Could not generate the initramfs" >&2
		return 1
	fi

	# Update bootloader
	echo "Updating bootloader configuration..."
	if ! update_bootloader; then
		echo "Could not update the bootloader configuration" >&2
		return 1
	fi

	# All done
	return 0
}

do_uninstall() {
	local version="${1}"

	# Check if we are removing the running kernel
	if [ "${version}" = "${RUNNING_VERSION}" ]; then
		echo "You cannot remove the currently running kernel ${RUNNING_VERSION}" >&2
		return 1
	fi

	# Remove initramfs
	rm -f "/boot/initramfs-${version}.img"

	# Update the bootloader configuration
	update_bootloader || return $?

	return 0
}

check_version() {
	local version="${1}"

	if [ -d "${MODULES_PATH}/${version}/kernel" ]; then
		return 0
	else
		return 1
	fi
}

main() {
	local action="${1}"
	local version="${2}"
	shift 2

	if [ -z "${version}" ]; then
		version="${RUNNING_VERSION}"
	fi

	case "${action}" in
		install)
			do_install "${version}" || return $?
			;;

		uninstall)
			do_uninstall "${version}" || return $?
			;;

		version)
			echo "${PACKAGE_NAME}: Version ${PACKAGE_VERSION}"
			return 0
			;;

		"")
			echo "No command given" >&2
			return 2
			;;

		*)
			echo "Invalid command: ${action}" >&2
			return 2
			;;
	esac
}

# Call main
main "$@" || exit ${?}