Information resources

[Phillip Susi]

I'm looking for resources I can read to learn more.  I mostly have some
basic questions that are probably in a FAQ or something, so if someone
could point me the right way I'd appreciate it.

Specifically some of the things I have been wondering are:

1)  It looks like the firmware is in the kernel tree in HEX file form.
Where can I find the source code?

2)  What is a "fence"?