#!/bin/sh

header() {
	printf "TIMEOUT %s\n" ${TIMEOUT} > ${OUTFILE}
	printf "DEFAULT entry0\n" >> ${OUTFILE}
	printf "MENU TITLE Boot menu\n" >> ${OUTFILE}
}

get_bootpath() {
	echo ${1} | sed "s#${BOOTPART}/#/#"
}

add_kernel() {
	ver=${1}
	kernel=$(get_bootpath "/boot/vmlinux-${ver}")
	initrd=$(get_bootpath "/boot/initramfs-${ver}.img")
	devicetreedir=$(get_bootpath "/boot/dtbs/dtbs-${ver}")
	fdt=$(get_bootpath "/boot/dtbs/dtbs-${ver}/${DTBPATH}")
	cmdline="${CMDLINE}"

	printf "LABEL entry%s\n" ${ENTRY} >> ${OUTFILE}
	printf "\tMENU LABEL Void Linux Version %s\n" ${ver} >> ${OUTFILE}
	printf "\tLINUX %s\n" ${kernel} >> ${OUTFILE}
	if [ -e "${BOOTPART}/${initrd}" ]; then
		printf "\tINITRD %s\n" ${initrd} >> ${OUTFILE}
	fi
	if [ -n "${USE_DEVICETREEDIR}" ]; then
		printf "\tDEVICETREEDIR %s\n" ${devicetreedir} >> ${OUTFILE}
	elif [ -n "${DTBPATH}" ] && [ -e "${BOOTPART}/${fdt}" ]; then
		printf "\tFDT %s\n" ${fdt} >> ${OUTFILE}
	fi
	if [ -n "${cmdline}" ]; then
		printf "\tAPPEND %s\n" ${cmdline} >> ${OUTFILE}
	fi
	ENTRY=$(expr ${ENTRY} + 1)
}

main() {
	if [ ! -d /boot/extlinux ]; then
		rm ${OUTFILE}
		exit 0
	fi

	if [ -e ${CONF} ]; then
		. ${CONF}
	fi

	if [ -z "${CMDLINE}" ]; then
		CMDLINE=$(cat /proc/cmdline)
	fi

	header

	for kernel in $(ls /boot/vmlinu[xz]-* | sort -rV); do
		ver=$(echo ${kernel} | sed "s#/boot/vmlinu[xz]-\(.*\)#\\1#")
		echo "Add kernel ${ver}"
		add_kernel ${ver}
	done
	mv ${OUTFILE} /boot/extlinux/extlinux.conf
}

CONF=/etc/default/extlinux
OUTFILE=$(mktemp)
BOOTPART=$(df -P /boot | tail -1 | awk '{ print $6 }')
ENTRY=0
main