BSP documentation

[sotko at isr.com (David Sotkowitz)]

Is there any documentation on writing a BSP? More specifically, on what HAS
to be in a BSP? A description, no matter how unpolished, of the minimum
requirements for a BSP would be useful, explaining what must be done and
where. This information is hard to tease out of existing BSP
implementations.

In the case I am looking at, some of the processor initialization is
already done prior to BSP start up initialization.

-- David Sotkowitz