[LinuxBIOS] Geode GX1 PCI, VGA and Sound configuration -- was Re: Televideo TC7020 successfully booted with LinuxBiosV2

[Kenji Noguchi]

Hi,

It's pretty informative. Thanks.

2007/5/8, Juergen Beisert <juergen127 at kreuzholzen.de>:

> On my system LinuxBIOS left all PCI irq registers at their reset value.

> > 3) Or, can/should I leave the configuration part to a OS as long as
> > irq_tables.c sets a proper irq_routing_table?   I've read about people
> > who booted LB with GX1 in the ML. Did they solely rely on the
> > irq_routin_table?
>
> Yes. With a working irq routing table and a (small) special Linux kernel patch
> (only with this patch Linux is able to setup the IRQ routing correctly. The
> patch was rejected in mainline, because it breaks other systems. The current
> kernel implementation is wrong, as it permuts the nibbles in the routing
> register. I have no idea how this could work on the other systems...)

ok, I think that's a right way that a payload or OS configures IRQ routing since
they need to initialize PCI controllers anyway, and it's not possible
for a bios to
configure all the add-on PCI devices.

My only concern is portability to other architecures. The struct
irq_routing_table
seems to be x86 PC specific.


> > > > Sound ,
>
> I'm working on it. And I can play sounds with it. But under higher system load
> it crashes yet. There is not interrupt available to setup the next sound data
> if the current one is finished. The hardware can only generate SMIs. So a
> second part of my driver polls the SMI statusbits and calls the sound driver
> when it flags "ready" for next data.

I noticed that CS5535 is very similiar to CS5530 except CS5535 has two more
DMAs.  I suspect the CS5535audio driver would work for CS5530 just by adding
PCI vendor/device ID.


> I can send you my whole embedded project. It contains graphics (special

I'm very much interested in it.  Please send it to me unless you are gonig to
put yout whole stuff to the wiki.  Thank you!

Kenji Noguchi

ps. anyone interested to port LB to MIPS?  gxemul is my target so far.