#!/bin/sh

board=
device=
dryrun=
imagedir=

get_boot_blockdev() {
	# Find the blockdevice where /boot is mounted from
	mount | sed -n -E 's:.*(/dev/mmcblk[0-9])p[0-9] on /boot .*:\1:p'
}

get_defaults() {
	if [ -z "$board" ] && [ -e /sys/firmware/devicetree/base/compatible ]; then
		case "$(cat /sys/firmware/devicetree/base/compatible 2>/dev/null)" in
		purism,librem5r*) board=librem5;;
		purism,librem5-devkit*) board=librem5-devkit;;
		esac
	fi

	if [ -z "$device" ]; then
		case "$board" in
		librem5*) device=/dev/mmcblk0 ;;
		esac
	fi

	if [ -z "$imagedir" ]; then
		imagedir="/usr/share/u-boot"
	fi
}

die() {
	echo "ERROR: $@"
	exit 1
}

usage() {
	get_defaults

	cat <<EOF
usage: $0 [-n,--dry-run] [-i,--imagedir <imagedir>] [-b|--board <board-type>] [-d|--device <device>] [-s|--skip-delay]

options:

 -b,--board <board>       Specify the board type: librem5
                          (current default: ${board:-none})

 -d,--device <device>     Specify the device where to install u-boot
                          (current default: ${device:-none})

 -i,--imagedir <imagedir> Specify u-boot image directory
                          (current default: ${imagedir:-none})

 -n,--dry-run             Print commands but don't execute them

 -s,--skip-delay          Skip delay and flash the image immediately

EOF
}

validate_checksum() {
	file="$1"
	file_sha512="$file.sha512"
	file_size=$(stat -c%s $file)
	device="$2"
	bs="$3"
	seek="$4"

	checksum0=$(cat $file_sha512 | awk {'print $1'})
	checksum1=$(dd if=$device bs=1 skip=$(($seek * $bs)) count=$file_size status=none | sha512sum | awk {'print $1'})
	if [ "$checksum0" != "$checksum1" ]; then
		echo "File: $checksum0"
		echo "Part: $checksum1"
		die "Checksum failed"
	fi
	echo "Successful U-Boot image checksum verification on $device :"
	echo -e "\t$checksum1"
}

while [ $# -gt 0 ]; do
	opt="$1"
	shift
	case "$opt" in
	-b|--board)
		case "$1" in
		librem5) board="librem5" ;;
		*) usage; exit 1;;
		esac
		shift
		;;
	-d|--device)
		device="$1"
		shift
		;;
	-i|--imagedir)
		imagedir="$1"
		shift
		;;
	-n|--dry-run)
		dryrun="echo"
		;;
	-s|--skip-delay)
		skip_delay="yes"
		;;
	--)
		break
		;;
	-*)
		usage
		exit 1
		;;
        esac
done

get_defaults
if [ -z "$board" -o -z "$device" -o -z "$imagedir" -o  ! -e "$imagedir" ]; then
	usage
	exit 1
fi

if [ -z "$dryrun" ]; then
	if [ -z "$skip_delay" ]; then
		echo "Updating $board u-boot in $device in 3 seconds..."
		sleep 3
	else
		echo "Updating $board u-boot in $device"
	fi
fi

(
set -e
case "$board" in
librem5)
	seek=33
	[ -e "$imagedir/librem5" ] || die "librem5 images not installed, apk add u-boot-librem5"
	$dryrun dd if=$imagedir/librem5/phone-boot.img of=$device bs=1024 seek="$seek" oflag=direct status=none
	[ -z "$dryrun" ] && validate_checksum $imagedir/librem5/phone-boot.img $device 1024 "$seek"
	;;
librem5-devkit)
	seek=33
	[ -e "$imagedir/librem5" ] || die "librem5-devkit images not installed, apk add u-boot-librem5-devkit"
	$dryrun dd if=$imagedir/librem5/devkit-boot.img of=$device bs=1024 seek="$seek" oflag=direct status=none
	[ -z "$dryrun" ] && validate_checksum $imagedir/librem5/devkit-boot.img $device 1024 "$seek"
	;;
esac
$dryrun sync
) || die "U-Boot installation in $device failed"

[ -z "$dryrun" ] && echo "Completed successfully."