[openfirmware] Porting OFW to custom hardware

[R&D4]

Hi all,

we are currently porting OFW to a custom board (codename Neptune) with 
is much like OLPC, but without SuperIO and keyboard controller.

First of all: is there any documentation about how to add a new custom 
platform? As a beginner I just copied lxdevel directory to one called 
neptune, changed some definitions inside:
* Makefile
* neptune.bth (taken from lxdevel.bth)
* config.fth

Is this correct?

Of couse, it's a bit hard for me to figure out, for example, where to 
look for some basic initialization (e.g. PLL, SDRAM, memory mapping).

AFAIK the "official" documentation is here:

http://www.firmworks.com/open_firmware/literature/

among these documents is there also a guide for porting OFW or about OFW 
"internals"? ("Open Firmware Command Reference" seems the closest to my 
needs)

Thanks in advance and Best Regards,