Write an OS for Beaglebone in C?

Write an OS for Beaglebone in C?

I have a good knowledge of the C programming language from a book I bought
at the store a while ago. I want to use this knowledge to develop a basic
Operating System for the Beaglebone board for fun. In order to continue, I
need to know the answer to the two following questions:
a) I have found a way to compile C to the beagleboard, but this requires
Linux. How can I compile C to run on the processor without Linux. I found
this:
http://www.ti.com/tool/starterware-sitara
I don't know if this is right though. I think TI makes Beagleboard, so
this could be it, but I am not sure.
b) When I do get a compiler, does anyone happen to know if there is a
helpful tutorial on making an OS for the Beagleboard? I found this:
http://wiki.osdev.org/ARM_Beagleboard
This is in assembly but not C though...
Any help is appreciated. I don't have a ton of experience, but I feel like
I know a lot of C and I could do it if I put my mind to it.
All help is appreciated!