Quesion on Startup and Initialization

I have a need to do some one time initialization of a device over i2c
after a reset. I am curious as to how the best way to handle this in
embedded linux (or linux for that matter).

It has to be done before USB and ethernet come up, but obviously after
the i2c driver is loaded.

1)How are these types of things typically handled in embedded linux
systems?
2)Do you write a little application that is called at some point, or
what?
3)If so, how would have it get called?
4)How do control the order of driver loading for the requirement
above?


Thanks In Advance.