There is certainly nothing easy about it. I have quite some experience with low-level and embedded devices, but hardware has progressed to the point where a Cortex M3 is quickly becoming the jellybean baseline throwaway uC, and have you seen the datasheet of one of these things?
The amount of stuff they do is incredible, and everything is interconnected in unexpected and intricate ways.
The amount of stuff they do is incredible, and everything is interconnected in unexpected and intricate ways.