#!/bin/sh

# apk add qemu-img losetup blkid parted dosfstools e2fsprogs wget tar
set -eu

: "${DISK:=gru-mmc.img}"
: "${DISKSIZE:=500M}"

readonly SCRIPT="${0##*/}"
readonly TMPDIR="$(mktemp -dt "${SCRIPT%.*}".XXXXXX)"
readonly APK_KEY="alpine-devel@lists.alpinelinux.org-60ac2099.rsa.pub"
readonly MIRROR="http://dl-cdn.alpinelinux.org/alpine"
readonly LOOPDEV="$(losetup --find)"
readonly KERNDEV="$LOOPDEV"p1
readonly BOOTDEV="$LOOPDEV"p2
readonly ROOTDEV="$LOOPDEV"p3

cleanup() {
	set +e
	mountpoint -q "$TMPDIR"/boot && umount "$TMPDIR"/boot
	mountpoint -q "$TMPDIR" && umount "$TMPDIR"
	losetup --detach-all
	rm -rf "$TMPDIR"
}

trap cleanup EXIT INT

kernel="linux-rockchip-6.1.2-r0.apk"

#if [ ! -f $kernel ]; then
#  wget https://dev.alpinelinux.org/~mps/riscv64/"$kernel"
#fi

#if [ ! -f "$DISK" ]; then
	echo "Creating qemu raw disk"
	qemu-img create -f raw "$DISK" "$DISKSIZE"
	chown "$USER":"$USER" "$DISK"
#else
#	echo "Disk already exists exiting."
#	exit 1
#fi

echo "Paritioning disk"
# fat32 64MB, ext4 rest of device
parted -s "$DISK" mktable gpt > /dev/null
cgpt create $DISK
secgpt=$(cgpt show $DISK | grep 'Sec GPT table' | awk '{print $1}')
endpart=$(expr $secgpt - 73728)
endpart=$(expr $secgpt - 335872)
cgpt add -i 1 -t kernel -b 8192 -s 65536 -l uboot -S 1 -T 5 -P 10 $DISK
cgpt add -i 2 -t data -b 73728 -s 262144 -l boot $DISK
cgpt add -i 3 -t data -b 335872 -s $endpart -l root $DISK
parted -s $DISK -- set 2 legacy_boot on
echo "Creating dirs and mounting"
losetup -P "$LOOPDEV" "$DISK"
mkfs.ext4 -qL boot "$BOOTDEV"
mkfs.ext4 -qL root "$ROOTDEV"
mount -t ext4 "$ROOTDEV" "$TMPDIR"
mkdir -p "$TMPDIR"/boot
mkdir -p "$TMPDIR"/etc/apk/keys
mount -t ext4 "$BOOTDEV" "$TMPDIR"/boot

echo "Setup apk keys and repositories"
wget -qP "$TMPDIR"/etc/apk/keys https://alpinelinux.org/keys/"$APK_KEY"
printf "$MIRROR/edge/%s\n" main community testing > "$TMPDIR"/etc/apk/repositories

echo "installing base packages"
apk --allow-untrusted --root "$TMPDIR" --arch aarch64 --initdb add \
	alpine-base alpine-baselayout alpine-conf kmod openrc \
  dbus util-linux blkid chrony \
	sysfsutils ssl_client ca-certificates-bundle alpine-keys \
	ethtool e2fsprogs e2fsprogs-extra libudev-zero libudev-zero-helper \
	iwd linux-firmware-rockchip linux-firmware-mrvl installkernel mkinitfs \
	agetty openresolv tar wget cgpt linux-gru
#apk --allow-untrusted --root "$TMPDIR" --arch aarch64 add $kernel

echo "Setting up services and inittab"
for rc in boot/bootmisc boot/hostname boot/modules boot/sysctl boot/urandom boot/networking \
	sysinit/devfs sysinit/hwdrivers sysinit/mdev sysinit/modules \
	shutdown/mount-ro shutdown/killprocs \
	default/dbus default/chronyd default/local; do
	ln -s /etc/init.d/"${rc##*/}" "$TMPDIR"/etc/runlevels/"$rc"
done

echo 'SUBSYSTEM=drm;.*   root:video 660 */usr/libexec/libudev-zero-helper' >>  $TMPDIR/etc/mdev.conf
echo 'SUBSYSTEM=input;.* root:input 660 */usr/libexec/libudev-zero-helper' >>  $TMPDIR/etc/mdev.conf

echo "Settting boot loader"
rootuuid=$(blkid -s PARTUUID -o value $ROOTDEV)

mkdir -p "$TMPDIR"/boot/extlinux
cat <<EOF > "$TMPDIR"/boot/extlinux/extlinux.conf
menu title Alpine
timeout 50
default gru

label gru
	menu label Alpine Linux
	kernel /vmlinuz-gru
	initrd /initramfs-gru
	fdtdir /dtbs-gru
	append console=tty1 earlyprintk=tty1 root=PARTUUID=$rootuuid rootfstype=ext4 rw rootwait init=/sbin/init nospectre_bhb loglevel=7
EOF
dd if=u-boot-depthcharge.kpart of=$KERNDEV

sed -i 's/^tty1.*/tty1::respawn:\/sbin\/agetty -L 115200 tty1 linux --login-pause --autologin root --noclear/' $TMPDIR/etc/inittab

echo "Finished, cleaning up"