[Nouveau] NV40 under Debian

[Lukas Schubert]

Hi list,

my media center PC is freshly installed with Debian 10.2 "Buster". It doesn't support Geforce 6800 GT (NV40) boards through the nvidia nor the nvidia-legacy drivers any longer. The legacy drivers worked up until Debian 9 "Stretch", but no longer.

I know that the hardware works because I can boot SystemRescueCD from CD and get a flawless desktop presentation on the attached full HD TV.

But in Debian 10, the colours are distorted. Have a look at "Nouveau.jpg" here: https://jumpshare.com/b/Se5d7xMu5tBSsR2Zcz8p
I can get the colours to work by starting the kernel with "nomodeset". Look at the same link, "NoModeSet.jpg".

SystemRescueCD (working nouveau version) uses an older kernel:
root at sysresccd /root % uname -a
Linux sysresccd 3.2.28-std300-amd64 #2 SMP Tue Aug 21 18:35:38 UTC 2012 x86_64 Intel(R) Core(TM)2 CPU 6420 @ 2.13GHz GenuineIntel GNU/Linux

Debian 10.2 (distorted colours) uses this kernel:
luker at michael:~$ uname -a
Linux michael 4.19.0-8-amd64 #1 SMP Debian 4.19.98-1 (2020-01-26) x86_64 GNU/Linux

Is there a configuration setting in nouveau that causes those weird colours?
Bit order/byte order maybe?

Thanks