Display issues/Freezing after installing Ubuntu on an iBook G3 notebook system.

[jharris1993]

Greetings!

Issue:
After installing Ubuntu 16.04 (PPC) on an iBook G3, with 640 megs Ram, using the minimal/network install disk, I end up with an unusable display, no virtual terminals, and a system that can only be shut-down by holding the power button down for 4+ seconds.

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I am the proud owner of an iBook G3, 640 megs RAM, and (as far as I know), a totally stock system except I installed a larger hard drive.

The system works. I had Tiger 10.4n installed on it and it worked "perfectly" as far as that goes. It also had a working installation of Ubuntu 10.n. Both of those systems were so old that they were unusable. I decided to install a more modern system on it and went through a number of iterations, including OpenBSD, and every installation ended up with the same result.

My system goes through the boot process and ends up with an unusable screen that looks like either a cloud nebula or an impressionist's painting after he took drugs. Unfortunately, I do not even get a text based login, so any suggestions to edit my such-and-so.conf or something that requires a text based console is not possible.

Also note that every other *nix system I have tried installing on this system produces the exact same post-install display. Re-installing Tiger produces a working system.

I have read many different forum threads, and have tried so many things including booting through the Open Firmware, that I am all but literally dizzy. Of course, it is entirely possible that someone's solution from a thread I read four-or-five days ago might end up fixing it, so if there seems to be an "obvious" answer, please suggest it.

I don't want to just toss this system to the wolves, (or use it for target practice), so I would appreciate any help anyone could provide.

Thanks!

Jim "JR"

Partial list of authorities:
I am sure that there are other sites that I consulted that I do not remember.
There is a whole other list of sites I consulted when trying to install OpenBSD that I don't remember as well.

https://ubuntuforums.org/showthread....ht=ppc+display
http://www.psychocats.net/ubuntu/minimal
http://forums.debian.net/viewtopic.p...927cf&start=15
https://help.ubuntu.com/community/In...tion/MinimalCD
https://www.debian.org/ports/powerpc.../index.en.html
https://help.ubuntu.com/16.04/instal...guide/powerpc/
https://help.ubuntu.com/community/Lu...tation/FAQ/PPC

[jharris1993]

Update (as this may not have been clear in the original post):

A reboot progresses through the OF boot process correctly and I get the yaboot prompt where I can, and have, tried various parameters. After yaboot, the screen becomes unusable and no virtual terminals work.

[gsahli]

I had exactly the same result on my PM G4 MDD - with a Radeon graphics chipset. I can't be sure you will have the same result, but try this at initial boot:
Linux radeon.agpmode=-1 modprobe.blacklist=ams #####(this is the boot> entry, type all as is, including spaces, not the ##)

If it works, put >append="radeon.agpmode=-1 modprobe.blacklist=ams"< into yaboot.conf

[jharris1993]

@gsahli
Thank you!

You are correct. I did not specify that this device has Radeon graphics hardware.

I am not sure where to find the "amsXXXX" entry you specified. Is it something within the Mac's device display utility? Do I find it via open firmware?

Should the "blacklist" parameter work directly from the yaboot command prompt during boot-time?

Thanks again for all your help!

Jim "JR"

[gsahli]

First time starting up, put those two arguments on the "Linux" command line. (DO NOT type the ###s - pound sign/hash tags are the typical comment start in linux)
Again - at the yaboot boot> prompt, type
Linux radeon.agpmode=-1 modprobe.blacklist=ams

[jharris1993]

Ahh! Now I understand.

In the past I've seen "[command]####" used to indicate some command followed by a string of digits, like "ams1234", so I was wondering what the digits could be.

Thanks for clarifying that.

[jharris1993]

I tried what you suggested, and it did not work. I would post pictures, but there seems to be no way to do that via the mobile site.

[gsahli]

At the boot> prompt, try "Linux 3"
I'm hoping this takes you to a terminal/commandline so you can do further troubleshooting.

[jharris1993]

Update:

I found an article somewhere that suggested "radeon.modeset=0", which I tried. Once I did that, I was able to get a usable text-based system that I could log-into. I ran into networking problems, other display problems, and a host of other things - so I decided to "drop back 10 and punt". In other words, I was wondering if the installation was defective somehow so I re-installed with the 16.n LTS alternate disk and did a full-up install.

About a half-day later after everything was installed. . . . . .

I ran into some annoying, (but trivial), problems with kernel modules not loading (thermal_windtunnel didn't exist) and one or two other tweaks that I don't remember.

Booting now produces a black screen with a cursor, (arrow-pointer), that responds to the mouse, but no background, no graphics, or anything even resembling a desktop. ALT-OPT [F-key] brings up a text session that I can log into and work with.

Any modeset other than "nomodeset" or "radeon.modeset=0" produces a frozen machine with no terminals available and a psychedelic screen display.

Apparently the 16.n install worked better than the 14.n install I tried before as nothing worked there. I'm being offered the opportunity (on the text login screen) to update to the latest 18.n LTS version and I am tempted, however after spending about four hours installing 16, I hesitate to jump through additional hoops only to find that my system is worse off than before.

Note that I re-tried all of the other "video=" parameters, etc., with no success.

Any additional help would be appreciated.

Jim "JR"

[gsahli]

My only other suggestion is to create an /etc/X11/xorg.conf like this:

Section "Device"
	Identifier "Radeon"
	Driver "radeon"
EndSection