Eric W. Biederman
ebiederman at lnxi.com
Wed Nov 17 13:32:00 CET 2004
Ok I am starting to dig into these and figure out what needs to happen
to get the ppc targets working again.
The hardest case currently appears to be the sandpointx3 with pmc
processor modules, so I will get to it last. The whole northboard/southboard
thing is interesting. But something we need to handle. I think
I have heard of the same thing with a few hypertransport based systems
as well. Which board is the bootrom that the systems starts
executing with on. The few schematics I have looked up so far
have a bootrom on the sandpoint and the MPCxxx pmc module.
The other datapoint I need to track down is are there other boards
the processor pmc modules can plug into. Or there tighter coupling than
I have not been able to track down documentation on cpu the embeddedplanet epc405
is using. In fact I'm not even certain which cpu it is using which is part of
the problem. Does that board use a northbridge at all or is the memory controller
and pci bus built into the cpu?
But it looks like I have tracked down enough information on the totalipact/briq,
to understand what is going on. Or at least well enough that I can get something
that will build and will be close to working built. So I am starting
there despite the fact it does not look like that port was ever quite
finished, or at least it was never built to handle the general case
as it has a hardcoded memory size.
One of the cases the northboard/southboard thing brings up is that we
don't have good infrastructure for handling plugin boards with lots
of chips that need special handling. If we can identify them we can
do something, the code is just not very general yet. It is likely we
want to be able to build a static device tree that describes a pluging
board that we can just graft to the main tree when we detect that
board. It is something to think about anyway.
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