I ran into this issue today.
I ran "bootd" and it started fine. After 5 sec, press "space" to get to => to "loader>" mode.
Once in loader mode, i ran 'Boot -s" command
You will end up at following prompt:
Enter full pathname of shell or 'recovery' for root password recovery or RETURN for /bin/sh: recovery
Y(ou have 10 sec to enter 'recovery', else restart process.
then I ended up at root>. You can optionally reset root password or install new image or whatever you wanted..
HTH
Z