Cell port

[Rafal Jaworowski]

Stephane E. Potvin wrote:
> 
> Small comment about the OpenFirmware dependency. Recent Linux kernels 
> started to required that all powerpc platforms provide what they call a 
> "flattened device tree" which is very similar to an OpenFirmware device 
> tree. It enables them to share the same code for standard Apple 
> computers providing an OpenFirmware and small embedded processors (like 
> the 8349e from FSL) that do not usually have OpenFirmware.
> 
> It might be worthwhile for anybody attempting to port to a new 
> architecture to look into adding support for something similar instead 
> of removing the OF dependency.
> 

Having the flat device tree is not cheap, as one has to provide the 
whole infrastructure, which is currently non-existent:

- the dtc 'compiler' to produce binary out of textual description of the 
device tree (the existing GPL-licensed could be used for quick start)

- in-kernel library of routines processing the device tree blob (node, 
properties etc.)

- loader(8) would need to be involved too (at least to pass the blob as 
part of metadata or so).

Introducing this is quite a big project for its own, and requires 
dealing with OpenFirmware internals, binding definitions etc. as FDT 
essentially mimics some part of it.

Rafal