#1 problem with Ubuntu is the splash screen. Usually you get that right off the bat with just an immediate black screen with a blinking cursor in the upper left, or just totally bizarre colors.
Originally Posted by jtbrookreson
How to fix:
At the second-stage yaboot boot: prompt, hit TAB to stop the automatic countdown. Now we are going to tell the kernel to ignore the ubuntu splash screen with an additional parameter, "nosplash"
(That's a capital L)
In addition to the splash screen, some have a problem with the framebuffer, and need to add another kernel parameter, "ofonly".
Again, at the 2nd-stage yaboot boot: prompt, enter:
Ok, now this should at least get you to X and a graphical login. However, even this is problematic at times because the Apple hardware doesn't play nice with any ppc distro's installer, and one must manually edit /etc/X11/xorg.conf.
Linux nosplash video=ofonly
(note - newer g4's and G5's sometimes don't have any problems at this stage - it all depends on the model)
If you can get a somewhat usable graphical desktop, the most universal way of editing xorg.conf is to fire up a terminal with root priveleges and start the nano text editor:
(It has to have root priveleges since /etc/X11/xorg.conf is a system file. Note the Capital-X in X11)
Make your edits. Save the new file with CTRL-O. Exit the nano editor with CTRL-X. Now either logout and log back in, or reboot the machine.
sudo nano /etc/X11/xorg.conf
IF the gui is not even workable at all, you can try the above editing with nano from a virtual terminal, by entering CTRL-ALT-F2. This will bring up a virtual terminal from which you login, and then edit the file.
If things are really bad, you may have to do this by rebooting with the installation cd, going into Linux single or use the "rescue" option which will look like it is going to reinstall, but you will eventually be prompted where your root partition is located. Drop into that, and then you can use the vi editor to make your changes. Since you are already root, there is no need for "sudo" to precede your commands.
The secret is to scour the threads, wikis, and even the ppc thread archives to find a reference xorg.conf file. Since things change over the years, these files may not work if they are just dropped in as-is, but crucial elements such as your horizontal and vertical frequencies should work since the hardware hasn't really changed over the years.
It can seem like a lot of work, but I wanted to be a bit more comprehensive about what you are jumping into. But don't blame the Linux installers - most of the pain comes from the Apple hardware not being designed to talk to anything but OSX, nor are the Apple folk just sending hardware data our way to make the developer's lives any easier.