efihelper

#!/bin/bash

#############################
#
## CONFIG LOAD
#
#############################
if [[ -e /etc/debianefihelper.conf ]]; then
	. /etc/debianefihelper.conf
else
	echo -e "Configuration file not found. This may be because you are opening\n\
the program for the first time or because the file has been deleted or moved.\n\
Please opening the program with 'first' parameter. Example: 'sudo efihelper first'"
fi



#############################
#
## PERM's and EFI DETECTION
#
#############################

if [[ $(id -u) != "0" ]]; then
	echo "Please run program with root permissions."
	exit 1
fi

if [[ ! -d "/sys/firmware/efi/efivars" ]]; then
	echo "Efi variables not found in this system. Aborting..."
	exit 1
fi


#############################
#
## CHECK PROGRAMS
#
#############################

checkprogram(){
	missingpacks=0
	command -v $1 >/dev/null 2>&1;
	if [[ $? -eq 1 ]]; then
		echo -e "Please install $1 before proceeding."
		missingpacks=$(( $missingpacks + 1 ))
	fi
}



#############################
#
## ROOTPART DETECTION
#
#############################

if [[ -n $ROOTDISK ]]; then
  	ROOTUUID="$(blkid -s UUID -o value $ROOTDISK)"
else
	ROOTUUID="$(findmnt / -o UUID | tail -n 1)"
fi



#############################
#
## EFIPART DETECTION
#
#############################

[[ ! -n $EFIDIR ]] && EFIDIR="/boot/efi"
if [[ ! -n $EFIPART ]]; then
	if [[ -n "$(findmnt $EFIDIR | grep dev | grep -oi nvme)" ]]; then
		EFIPART="$(findmnt $EFIDIR | grep dev | awk '{print $2}' | sed 's/p/ -p /g')"
	elif [[ -n "$(findmnt $EFIDIR | grep dev | awk '{print $2}' | grep -o sd)" ]]; then
		disk="$(findmnt $EFIDIR | grep dev | awk '{print $2}' | cut -d "/" -f3 | grep -o '[a-z]*')"
		part="$(findmnt $EFIDIR | grep dev | awk '{print $2}' | cut -d "/" -f3 | grep -o '[0-9]*')"
		EFIPART="/dev/$disk -p $part"
	elif [[ -n "$(findmnt $EFIDIR | grep dev | awk '{print $2}' | grep -o mmcblk)" ]]; then
		EFIPART="$(findmnt $EFIDIR | grep dev | awk '{print $2}' | sed 's/p/ -p /g')"
	fi
fi



#############################
#
## TARGET
#
#############################

TARGET="$EFIDIR/$(cat /etc/machine-id)"
[[ ! -d $TARGET ]] && mkdir -p $TARGET



#############################
#
## COPY FILES TO ESPDIR
#
#############################

copyfilestoesp(){
	[[ ! -d $TARGET/$1 ]] && mkdir -p $TARGET/$1 || rm -f $TARGET/$1/{linux,initrd}
	cp /boot/vmlinuz-$1 $TARGET/$1/linux
	cp /boot/initrd.img-$1 $TARGET/$1/initrd
}



#############################
#
## INSTALL ENTRY via EFISTUB
#
#############################

installefistubentry(){
	echo "Installing new entry (version $1)"
	nkernel="/$(cat /etc/machine-id)/$1/linux"
	ninitrd="\\$(cat /etc/machine-id)\\$1\\initrd"

	copyfilestoesp $1
	
	[[ -n "$(efibootmgr | grep $1)" ]] && efibootmgr -qBb $(efibootmgr | grep $1 | cut -d '*' -f1 | sed "s/Boot//g")

	efibootmgr -q -d $EFIPART \
		-c -L "$NAME - ($DISTCODENAME) ($1)" \
		-l $nkernel \
		-u "root=UUID=$ROOTUUID initrd=$ninitrd $PARAMS" -v
}



##################################
#
## INSTALL ENTRY via SYSTEMDBOOT
#
##################################

installsystemdbootentry(){
	echo "Installing new entry (version $1)"
	nkernel="/$(cat /etc/machine-id)/$1/linux"
	ninitrd="/$(cat /etc/machine-id)/$1/initrd"

	copyfilestoesp $1

	[[ ! -n "$(efibootmgr | grep 'Linux')" ]] && bootctl install

	echo -e "\
title\t\t$NAME - ($DISTCODENAME)\n\
version\t\t$1\n\
machine-id\t$MACHID\n\
options\t\troot=UUID=$ROOTUUID $PARAMS\n\
linux\t\t$nkernel\n\
initrd\t\t$ninitrd" | tee $EFIDIR/loader/entries/${MACHID}-${1}.conf
	exit
}



##################################
#
## REMOVE ENTRY via SYSTEMDBOOT
#
##################################

removesystemdbootentry(){
	echo "Removing systemdboot entry (version $1)"

	[[ -d "$TARGET/$1" ]] && rm -rf $TARGET/$1
	[[ -e "$TARGET/loader/entries/${MACHID}-${1}.conf" ]] && rm /boot/efi/loader/entries/${MACHID}-${1}.conf

	exit 0
}




#############################
#
## REMOVE ENTRY via EFISTUB
#
#############################

removefistubentry(){
	echo "Removing efistub entry (version $1)"

	[[ -d "$TARGET/$1" ]] && rm -f $TARGET/$1/{linux,initrd}
	[[ -n $(efibootmgr -v | grep $1) ]] && efibootmgr -qBb $(efibootmgr | grep $1 | cut -d '*' -f1 | sed "s/Boot//g")
	[[ -z "$(ls -A $TARGET/$1)" ]] && rmdir $TARGET/$1
	
	exit 0
}




#############################
#
## FIRST SETUP
#
#############################

checkprogram lsb_release
checkprogram efibootmgr
[[ $missingpacks -ge 1 ]] && exit 1

firstsetup(){
	if [[ -n "$(apt list --installed | grep grub)" ]]; then
		echo -e "Grub detected in the system. This may restrict or break the operation of the efihelper program.\n\
Do you want to uninstall grub? (If you wish, you can then reinstall Grub and uninstall this program.) [Y/N]"
		read -p "> " result
		case $result in
			y|Y|yes|YES)
				apt list --installed | grep grub | cut -d '/' -f1 | xargs sudo apt remove -y
				exit
			;;
			n|N|no|NO)
				exit 1
			;;
		esac
	fi


	if [[ -e "/etc/debianefihelper.conf" ]]; then
		echo -e "Config file is available in /etc.\nDo you want to continue?\nPress <Enter> to continue or press <Ctrl+C> to cancel operation"
		read
	fi

	if [[ ! -e "/etc/kernel/postinst.d/zz-efihelper"  ]]; then
		mkdir -p /etc/kernel/postinst.d >/dev/null
		echo -e '#!/bin/bash\n/usr/local/bin/efihelper install $1' > /etc/kernel/postinst.d/zz-efihelper
		chmod +x /etc/kernel/postinst.d/zz-efihelper
	fi

	if [[ ! -e "/etc/kernel/postrm.d/zz-efihelper"  ]]; then
		mkdir -p /etc/kernel/postrm.d >/dev/null
		echo -e '#!/bin/bash\n/usr/local/bin/efihelper remove $1' > /etc/kernel/postrm.d/zz-efihelper
		chmod +x /etc/kernel/postrm.d/zz-efihelper
	fi

	if [[ ! -e "/etc/initramfs/post-update.d/zz-efihelper"  ]]; then
		mkdir -p /etc/initramfs/post-update.d >/dev/null
		echo -e '#!/bin/bash\n/usr/local/bin/efihelper update $1' > /etc/initramfs/post-update.d/zz-efihelper
		chmod +x /etc/initramfs/post-update.d/zz-efihelper
	fi

	FILEVARIABLES='################################################\n#\n## BootLoader Method (systemdboot or efistub)\n## EFI partition directory (/boot or /boot/efi)\n#\n################################################\n'
	FILEVARIABLES+='METHOD="systemdboot"\n'
	FILEVARIABLES+="EFIDIR=\"$(cat /etc/fstab | grep efi | head -n 1 | awk '{print $2}')\"\n\n"
	FILEVARIABLES+='###################################################################################\n#\n## Changing the values below may compromise program stability.\n## If you encounter such a problem, type "sudo efihelper first" to reset the file\n#\n###################################################################################\n'
	FILEVARIABLES+="ROOTDISK=\"$(mount | grep ' / ' | cut -d ' '  -f1)\"\n"
	FILEVARIABLES+="EFIPART=\"$EFIPART\"\n"
	FILEVARIABLES+="MACHID=\"$(cat /etc/machine-id)\"\n"
	FILEVARIABLES+="NAME=\"$(lsb_release -i | awk '{print $3}') Linux $(lsb_release -r | awk '{print $2}')\"\n\n"
	FILEVARIABLES+="if [[ \"\$(lsb_release -c | awk '{print \$2}')\" == \"jammy\"  ]]; then\n\tDISTCODENAME='Jammy Jelfish'\n\
elif [[ \"\$(lsb_release -c | awk '{print \$2}')\" == \"impish\"  ]]; then\n\tDISTCODENAME='Impish Indri'\n\
elif [[ \"\$(lsb_release -c | awk '{print \$2}')\" == \"hirsute\"  ]]; then\n\tDISTCODENAME='Hirsute'\n\
elif [[ \"\$(lsb_release -c | awk '{print \$2}')\" == \"focal\"  ]]; then\n\tDISTCODENAME='Focal Fossa'\n\
elif [[ \"\$(lsb_release -c | awk '{print \$2}')\" == \"bionic\"  ]]; then\n\tDISTCODENAME='Bionic Beaver'\n\
fi\n\n"
	FILEVARIABLES+="PARAMS=\"$(cat /proc/cmdline | cut -d ' ' -f3-)\""

	echo -e $FILEVARIABLES | tee /etc/debianefihelper.conf

	exit
}


#############################
#
## COMMAND LINE
#
#############################
case $1 in
	install)
		if [[ $METHOD == "systemdboot" ]]; then
			installsystemdbootentry $2
		elif [[ $METHOD == "efistub" ]]; then
			installefistubentry $2
		else
			echo "Current method is missing, please set the METHOD environment in /etc/debianefihelper.conf file."
			exit 1
		fi

	;;
	remove)
		if [[ $METHOD == "systemdboot" ]]; then
			removesystemdbootentry $2
		elif [[ $METHOD == "efistub" ]]; then
			removefistubentry $2
		else
			echo "Current method is missing, please set the METHOD environment in /etc/debianefihelper.conf file."
			exit
		fi
	;;
	update)
		if [[ $METHOD == "systemdboot" ]]; then
			echo "Updating files (version $2)"
			copyfilestoesp $2
		elif [[ $METHOD == "efistub" ]]; then
			echo "Updating files (version $2)"
			copyfilestoesp $2
		else
			echo "Current method is missing, please set the METHOD environment in /etc/debianefihelper.conf file."
			exit
		fi
	;;
	first)
		firstsetup
	;;
esac