From bf29c31f5c80cd62b60db5c097fc3c32d80d9f94 Mon Sep 17 00:00:00 2001
From: alientim <tim@eertmoed.de>
Date: Tue, 15 Oct 2024 10:47:09 +0200
Subject: [PATCH] =?UTF-8?q?root/remove=5Funused=5Fkernel.sh=20hinzugef?=
 =?UTF-8?q?=C3=BCgt?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 root/remove_unused_kernel.sh | 146 +++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 root/remove_unused_kernel.sh

diff --git a/root/remove_unused_kernel.sh b/root/remove_unused_kernel.sh
new file mode 100644
index 0000000..54c105c
--- /dev/null
+++ b/root/remove_unused_kernel.sh
@@ -0,0 +1,146 @@
+#!/bin/bash
+set -eou pipefail
+readonly VERSION="v0.2.2"
+readonly GITREPO="https://github.com/framps/raspberryTools"
+readonly MYSELF="$(basename "$(test -L "$0" && readlink "$0" || echo "$0")")"
+readonly MYNAME=${MYSELF%.*}
+readonly DELETED_KERNELS_FILENAME="$MYNAME.krnl"
+function show_help() {
+	echo "$MYSELF $VERSION ($GITREPO)"
+	echo
+	echo "Check for unnecessary kernels for the existing Raspberry hardware."
+	echo "Optionally delete and save installed kernels for later reinstallation or reinstall the previously deleted kernels"
+	echo
+	echo "Usage: $MYSELF -i [-e] | -u [-e] | -h | -? | -v"
+	echo "-e: deactivate dry run mode and modify system"
+	echo "-i: reinstall kernels deleted with option -u"
+	echo "-u: uninstall any unused kernels"
+	echo "-h: display this help"
+	echo "-v: display version"
+}
+function info() {
+	echo "--- $@"
+}
+function error() {
+	echo "??? $@"
+}
+function yesNo() {
+
+	local answer=${1:0:1}
+	answer=${1:-"n"}
+	[[ "Yy" =~ $answer ]]
+	return
+}
+function check4Pi() {
+	dpkg --print-architecture | grep -q -E "arm(hf|64)"
+}
+function do_uninstall() {
+	local availableKernels="$(dpkg --list | awk '/^ii[[:space:]]+linux-image/ { print $2 }')"
+	local usedKernel="$(uname -a | awk '{ print "linux-image-" $3 }')"
+	local unusedKernels="$(grep -v "$usedKernel" <<< "$availableKernels" | xargs -I {} echo "{}")"
+	if [[ -z "$unusedKernels" ]]; then
+		error "No unused kernels detected"
+		exit 1
+	fi
+	local keptKernel="$(grep "$usedKernel" <<< "$availableKernels" | xargs -I {} echo "{}")"
+	if [[ -z "$keptKernel" ]]; then
+		error "No kernel will be kept"
+		exit 1
+	fi
+	info "Following kernel will be kept"
+	echo "$keptKernel"
+	local numUnusedKernels="$(wc -l <<< "$unusedKernels")"
+	info "Following $numUnusedKernels unused kernels will be deleted"
+	echo "$unusedKernels"
+	if (( $MODE_EXECUTE )); then
+		local answer
+		read -p "Are you sure to delete all $numUnusedKernels unused kernels ? (y/N) " answer
+		if ! yesNo "$answer"; then
+			exit 1
+		fi
+		read -p "Do you have a backup ? (y/N) " answer
+		if ! yesNo "$answer"; then
+			exit 1
+		fi
+		set +e
+		if [[ -e /boot/$DELETED_KERNELS_FILENAME ]]; then
+			sudo rm /boot/$DELETED_KERNELS_FILENAME
+			(( $? )) && { error "Failure deleting /boot/$DELETED_KERNELS_FILENAME"; exit 42; }
+		fi
+		info "Saving $numUnusedKernels unused kernel names in /boot/$DELETED_KERNELS_FILENAME"
+		echo "$unusedKernels" >> $DELETED_KERNELS_FILENAME; sudo mv $DELETED_KERNELS_FILENAME /boot
+		(( $? )) && { error "Failure collecting kernels"; exit 42; }
+		info "Removing $numUnusedKernels unused kernels"
+		echo "$unusedKernels" | xargs sudo apt -y remove
+		(( $? )) && { error "Failure removing kernels"; exit 42; }
+		set -e
+	fi
+}
+function do_install() {
+	if [[ ! -e /boot/$DELETED_KERNELS_FILENAME ]]; then
+		info "No unused kernels found"
+		exit 0
+	fi
+	local numUnusedKernels=$(wc -l /boot/$DELETED_KERNELS_FILENAME | cut -f 1 -d ' ')
+	if (( ! $MODE_EXECUTE )); then
+		info "Following $numUnusedKernels unused kernels will be installed"
+		while IFS= read -r line; do
+			echo "$line"
+		done < /boot/$DELETED_KERNELS_FILENAME
+	else
+		local errorOccured=0
+		info "Installing $numUnusedKernels unused kernels"
+		echo "$(</boot/$DELETED_KERNELS_FILENAME)"
+		while IFS= read -r line; do
+			sudo apt -y install $line
+			set +e
+			(( errorOccured |= $? ))
+			set -e
+		done < /boot/$DELETED_KERNELS_FILENAME
+		if (( ! errorOccured )); then
+			sudo rm /boot/$DELETED_KERNELS_FILENAME
+		else
+			error "Errors occured when installing kernels"
+		fi
+	fi
+}
+echo "$MYSELF $VERSION ($GITREPO)"
+if ! check4Pi; then
+	error "No RaspberryPi detected"
+	exit 1
+fi
+MODE_INSTALL=0
+MODE_UNINSTALL=0
+MODE_EXECUTE=0
+if (( $# == 0 )); then
+	MODE_UNINSTALL=1
+else
+	while getopts ":ehiuv?" opt; do
+		case "$opt" in
+			e) MODE_EXECUTE=1
+				;;
+			h|\?)
+				show_help
+				exit 0
+				;;
+			i) MODE_INSTALL=1
+				;;
+			u) MODE_UNINSTALL=1
+				;;
+			v) echo "$MYSELF $VERSION"
+				exit 0
+				;;
+			*) echo "Unknown option $opt"
+				show_help
+				exit 1
+				;;
+		esac
+	done
+fi
+if (( $MODE_INSTALL )); then
+	do_install
+elif (( $MODE_UNINSTALL )); then
+	do_uninstall
+else
+	show_help
+fi
\ No newline at end of file