#!/bin/sh

# apk add qemu-img qemu-openrc losetup blkid sgdisk e2fsprogs wget tar
set -eu


: "${DISK:=rv64-vm-mmc.img}"
: "${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 BOOTDEV="$LOOPDEV"p1
readonly ROOTDEV="$LOOPDEV"p2

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

rm -f $DISK
truncate -s $DISKSIZE $DISK

echo "Paritioning disk"
sgdisk --clear --set-alignment=1 \
 	-n 1:2048:+128MiB: -c 1:boot -A 1:set:2 \
 	-n 2::: -c 2:root \
"${DISK}"

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 riscv64 --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 \
	linux-firmware-none installkernel mkinitfs \
	agetty tar tzdata openssh wget sgdisk linux-edge

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"
bootuuid=$(blkid -s UUID -o value $BOOTDEV)
echo "LABEL=boot	/boot	ext4	auto" >> $TMPDIR/etc/fstab

rootuuid=$(blkid -s UUID -o value $ROOTDEV)
echo "creating extlinux.conf, u-boot setup"

mkdir -p "$TMPDIR"/boot/extlinux
cat > $TMPDIR/boot/extlinux/extlinux.conf<<'EOF'
TIMEOUT 50
PROMPT 1
DEFAULT edge

MENU TITLE riscv64

LABEL edge
MENU LABEL alpine linux-edge kernel
KERNEL /vmlinuz-edge
INITRD /initramfs-edge
APPEND "modules=sd-mod,usb-storage,ext4,f2fs root=/dev/vda2 rw rootwait console=ttyS0 earlycon=sbi loglevel=15"
EOF



sed -i 's/^tty1.*/tty1::respawn:\/sbin\/agetty -L 115200 tty1 linux --login-pause --autologin root --noclear/' $TMPDIR/etc/inittab
sed -i 's/^#ttyS0/ttyS0/' $TMPDIR/etc/inittab
sed -i 's/^ttyS0.*/ttyS0::respawn:\/sbin\/agetty -L 115200 ttyS0 linux --login-pause --autologin root --noclear/' $TMPDIR/etc/inittab

echo "Finished, cleaning up"