#/bin/sh
#
#	$NetBSD: zfsroot.rc,v 1.1 2020/02/22 09:53:47 roy Exp $
#	ZFS on Root boot strapper

# Configurable - define the ZFS root pool and ROOT.
# XXX Can these be set in boot.cfg?
# Assumption - the root pool is set to legacy mount.
rpool=rpool
rroot=ROOT

# Assumption - the boot device is named boot.
# Could use dk0, wd0a, etc instead.
# XXX Can be exposed by sysctl kern.boot_device?
bootdev="NAME=boot"

# Setup some stuff incase things go south and we drop to the shell
export HOME=/
export PATH=/sbin:/bin:/usr/sbin:/usr/bin
umask 022

echo
echo "Starting ZFS on root boot strapper"

# Avoid having the solaris and zfs modules in ramdisk directly.
# Means we don't need to update the ramdisk with the kernel modules
# or load them from boot.cfg so it's less pain for the user.
#bootdev="$(/sbin/sysctl -n kern.boot_device)"
modpath="$(/sbin/sysctl -n kern.module.path)"
modmnt=/mnt
echo "Copying needed kernel modules from $bootdev:$modpath"
case "$bootdev" in
*=*|"/"*)	;;
*)		bootdev="/dev/$bootdev";;
esac
/sbin/mount -o ro "$bootdev" "$modmnt"
/sbin/mount -t tmpfs none /stand
for m in solaris zfs; do
	p="$modpath/$m"
	if [ ! -e "$modmnt/$p/$m.kmod" ]; then
		echo "$modmnt/$p/$m.kmod not found!" >&2
		continue
	fi
	echo "	$m.kmod"
	/bin/mkdir -p "$p"
	/bin/cp "$modmnt/$p/$m.kmod" "$p"
done
# zpool list will load the needed modules, then we can dispose of the mounts.
/sbin/zpool list >/dev/null 2>&1
/sbin/umount /stand
/sbin/umount "$modmnt"
echo

echo "Importing $rpool, mounting and pivoting"
# If we can mount the ZFS root partition to /altroot
# then chroot to it and start /etc/rc
if /sbin/zpool import -f -N "$rpool" && \
   /sbin/mount -t zfs "$rpool/$rroot" /altroot; then
	# This ensures that mountall mounts all ZFS mounts set to automount.
	if [ ! -e /altroot/etc/zfs/zpool.cache ]; then
		echo >/altroot/etc/zfs/zpool.cache
	fi
	/sbin/sysctl -w init.root=/altroot
fi