#!/bin/sh

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

: "${DISK:=riscv-mmc.img}"
: "${DISKSIZE:=300M}"

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

kernel="linux-starfive-5.19.0-r5.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 "$DISK" mktable gpt > /dev/null
parted -s "$DISK" unit s -- mkpart primary ext4 2048 133119 > /dev/null
parted -s "$DISK" -- mkpart primary ext4 65MiB 100% > /dev/null

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

cat <<EOF > "$TMPDIR"/boot/uEnv.txt
fdt_high=0xffffffffffffffff
initrd_high=0xffffffffffffffff

scriptaddr=0x88100000
script_offset_f=0x1fff000
script_size_f=0x1000

kernel_addr_r=0x84000000
kernel_comp_addr_r=0x90000000
kernel_comp_size=0x10000000

fdt_addr_r=0x88000000
ramdisk_addr_r=0x88300000

bootcmd=devnum=0; run mmc_boot
bootcmd_mmc0=devnum=0; run mmc_boot
distro_bootcmd=run bootcmd_mmc0
EOF

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 "$TMPDIR" --arch riscv64 --initdb add \
	alpine-base alpine-baselayout alpine-conf kmod openrc \
  dbus util-linux blkid chrony \
	sysfsutils ssl_client ca-certificates-bundle alpine-keys \
	ethtool e2fsprogs e2fsprogs-extra libudev-zero libudev-zero-helper \
	iwd linux-firmware-brcm linux-firmware-cypress installkernel mkinitfs \
	agetty openresolv tar wget
apk --allow-untrusted --root "$TMPDIR" --arch riscv64 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 UUID -o value $ROOTDEV)

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

label alpine
	menu label Alpine Linux
	kernel /vmlinuz-starfive
	initrd /initramfs-starfive
	fdt /dtbs-starfive/starfive/jh7100-starfive-visionfive-v1.dtb
	append earlycon=sbi rw root=UUID=$rootuuid rootfstype=ext4 rootwait console=ttyS0,115200 console=tty0 stmmaceth=chain_mode:1
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"