I thought having a "big binary blob" wasn't supposed to be a problem ;-)

http://lists.xen.org/archives/html/xen-users/2016-04/msg00031.html

> [Xen-users] Debian 8.4, EFI, and systemd = Tricky
> ...
> My problem is that it hangs when trying so init systemd on dom0
> ...
> systemd is new to me. I would have expected that I could exec it from the shell and ideally it all should work, if everything was actually correctly working.
>
> At this point exec /bin/systemd hangs the machine, no output just a cursor(like every other hang)
> I don't know how I can step through, or emulate systemd to see where the error occurs.

Perhaps SysVinit would be similarly opaque in a failure, but I'm assuming that if you keep all the scripts away from it then it'll do very little and have much less chance of going wrong.