[U-Boot] Newbie question

[Donald Dade]

I recently bought a Jetson TK1 with the intent of learning all about ARM
board bring up; essentially everything that happens between the reset
vector and the spawning of the init process (in Linux). I've got a good
understanding of this for x86, and I'd like to similarly understand what
happens with an ARM SoC.

I've been having a rough go of it, for example I cannot even find in
explicit terms what the reset vector address is. I began to think that
maybe I'm presupposing too many x86 artifacts and that that's not at all
how ARM works. x86 has a lot of cruft left over from the 70s, after all.

So I know that there is a u-boot port for the Jetson, so I cloned the
source, started swimming through it, and quickly started to drown :)

So, my questions are these:

Can anyone briefly explain how the build system works, i.e. how the source
is configured to build for Jetson, and how I find where u-boot's entry
point is, so I can just look at what it does?

Thank you,

Don