help with nouveau on ubuntu powerpc, GeForce4MX (NV17)

[gsahli]

PowerMac G4 MDD/867 GForce4MX (NV17)
I have never been able to successfully boot to X with any distro that uses nouveau instead of nv driver.
The only reasonably-current distro I can get to work right now is Debian 6.0.9 with nv.

At X startup I get errors:
Nouveau: Invalid ROM contents
Nouveau returns -22

I get a black screen with mouse pointer. After moving mouse I find a text input location and type my password, and that gives me a basic X desktop (using lubuntu so it's OpenBox) with 4 bit depth. I'm pretty sure it's not using nouveau at that point.

sudo xrandr gives "Can't open Display."

Some info from Xorg log (trimmed):

~/Documents/ubuntu_PPC$ egrep 'EE|WW' Xorg.0.log
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 57.187] (EE) [drm] failed to open device
[ 57.187] (EE) No devices detected.
[ 57.189] (WW) Warning, couldn't open module nvidia
[ 57.189] (EE) Failed to load module "nvidia" (module does not exist, 0)
[ 57.193] (WW) Warning, couldn't open module modesetting
[ 57.193] (EE) Failed to load module "modesetting" (module does not exist, 0)
[ 57.215] (WW) xf86OpenConsole: setpgid failed: Operation not permitted
[ 57.215] (WW) xf86OpenConsole: setsid failed: Operation not permitted
[ 57.296] (EE) [drm] failed to open device
[ 57.842] (EE) AIGLX: reverting to software rendering

I think the nouveau developers didn't have access to a Mac-version GeForce4MX, so their probe doesn't recognize the NV17 card.
Any ideas for troubleshooting further or how to overcome this?

[gsahli]

More info:
killed lightdm and sudo'd to su.
ran Xorg -configure
Here's the output:

X.Org X Server 1.15.1
Release Date: 2014-04-13
X Protocol Version 11, Revision 0
Build Operating System: Linux 3.2.0-53-powerpc64-smp ppc Ubuntu
Current Operating System: Linux schooner2 3.13.0-24-powerpc-smp #47-Ubuntu SMP Sat May 3 02:03:13 UTC 2014 ppc
Kernel command line: root=UUID=219c8b58-7e5b-49f3-a715-9c552f70df25 ro quiet splash video=1280x1024:60
Build Date: 16 April 2014 01:45:07PM
xorg-server 2:1.15.1-0ubuntu2 (For technical support please see http://www.ubuntu.com/support)
Current version of pixman: 0.30.2
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Tue May 13 22:42:45 2014
List of video drivers:
s3
sisusb
ati
r128
mach64
sis
nouveau
trident
tdfx
savage
radeon
mga
fbdev
(++) Using config file: "/root/xorg.conf.new"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
Number of created screens does not match number of detected devices.
Configuration failed.
(EE) Server terminated with error (2). Closing log file.