Re: Changing ibm4xx device tree.

[Simon Burge <simonb%wasabisystems.com@localhost>]

Jachym Holecek wrote:

> [ what hangs of what discussion ]

Pretty much agree with all you say here.

> Unrelated to the original point -- what about turning OPB and PLB to
> indirect-config busses? From my (Virtex-centric) POV, both of them
> are general purpose busses w/o any autodetection mechanism, their
> address space layout may be different on every FPGA firmware. Further,
> there may be more then one OPB controller connected to the PLB.
> 
> I'm actually working with a design where OPB is hooked at different
> address and hosts different devices then any existing 4xx port. It
> seems more reasonable to hardwire base addresses to kernel config
> files (or config fragments, where sharing makes sense) then in the
> code itself, IMO.

Going the other way, I don't think it makes any sense at all to have to
specify hardware addresses in the kernel config files for SoCs where
it's impossible for devices to appear at different addresses.  Which
doesn't help you at all :-/

> Or perhaps there's a good way to handle this with plb/opb as-is?

I suspect the easiest way is to have a separate OPB/PLB implementation
for indirect config for Virtex.

Cheers,
Simon.
--
Simon Burge                            <simonb%wasabisystems.com@localhost>
NetBSD Support and Service:         http://www.wasabisystems.com/