#!/bin/bash

# Copyright (c) 2017 The Armbian Project https://www.armbian.com/
#
# This file is licensed under the terms of the GNU General Public
# License version 2. This program is licensed "as is" without any
# warranty of any kind, whether express or implied.

if [[ ! -n $1 ]]; then
	echo >&2 "Usage: $0 <overlay_source_file.dts>"
	exit -1
fi

if [[ $EUID -ne 0 ]]; then
	echo >&2 "This program must be run with superuser rights"
	exit -1
fi

if [[ ! -f $1 ]]; then
	echo >&2 "Can't open file $1. File does not exist?"
	exit -1
fi

if [[ $1 == *.dts ]]; then
	fname=$(basename $1 .dts)
else
	echo >&2 "Overlay source file name should have the .dts extension"
	exit -1
fi

if [[ ! -f /etc/armbian-release || ! -f /boot/armbianEnv.txt ]]; then
	echo >&2 "Armbian is not installed properly. Missing armbian-release or armbianEnv.txt"
	exit -1
fi

. /etc/armbian-release

if [[ $LINUXFAMILY != sunxi && $LINUXFAMILY != sun8i ]]; then
	echo >&2 "Overlays are supported only on A10, A20, H3, H5 and A64 based boards"
	exit -1
fi

if [[ $BRANCH != next && $BRANCH != dev ]]; then
	echo >&2 "Overlays are supported only on mainline kernel based images"
	exit -1
fi

if [[ ! -d /lib/modules/$(uname -r)/build/scripts/ ]]; then
	echo >&2 "Kernel headers are not installed properly. Please install the kernel headers package"
	exit -1
fi

if [[ ! -x /lib/modules/$(uname -r)/build/scripts/dtc/dtc ]]; then
	echo >&2 "Missing dtc compiler in kernel headers directory. Please reinstall the kernel headers package"
	exit -1
fi

if [[ ! -d /boot/overlay-user ]]; then
	mkdir -p /boot/overlay-user
fi

temp_dir=$(mktemp -d)

echo "Compiling the overlay"

/lib/modules/$(uname -r)/build/scripts/dtc/dtc -@ -q -I dts -O dtb -o ${temp_dir}/${fname}.dtbo $1

if [[ $? -ne 0 ]]; then
	echo >&2 "Error compiling the overlay"
	exit -1
fi

echo "Copying the compiled overlay file to /boot/overlay-user/"
cp ${temp_dir}/${fname}.dtbo /boot/overlay-user/${fname}.dtbo

if grep -q '^user_overlays=' /boot/armbianEnv.txt; then
	line=$(grep '^user_overlays=' /boot/armbianEnv.txt | cut -d'=' -f2)
	if grep -qE "(^|[[:space:]])${fname}([[:space:]]|$)" <<< $line; then
		echo "Overlay ${fname} was already added to /boot/armbianEnv.txt, skipping"
	else
		sed -i -e "/^user_overlays=/ s/$/ ${fname}/" /boot/armbianEnv.txt
	fi
else
	sed -i -e "\$auser_overlays=${fname}" /boot/armbianEnv.txt
fi

echo "Reboot is required to apply the changes"