Do you, by any chance, know of a resource that documents the process of actually getting your toy OS (which I assume was cross-compiled) to run on another board such as the BBB or the RPi?
Sorry for the late reply, I just saw your message. I don't have a toy OS (not enough spare time), but I did work on one as part of my job.
I don't know of any documents, but the way you'd generally want to do it is wrap hardware- and board-specific parts of your code in a hardware-agnostic interface which is what you use to write higher-level code in the system. That way, getting the OS to run on another CPU or board is all about writing the relevant callbacks. You can get the general idea from Linux's mach-* and plat-* files. This isn't really OS-specific; I'm pointing at Linux because it will probably be easiest to get documentation about it, though my personal preference is elsewhere.
It looks pretty cool but I think it would be nice if you could put the instructions somewhere more visible. Maybe I'm just retarded but I couldn't figure it out until I noticed the little question mark. Maybe somewhere on the side rather than below.
http://mcdlr.com/check-your-privilege/