I ran into some troubles during the first few reboots after installing FC10. I have an older G4 power macintosh that I upgraded the drives, and ram on. It ran Macos Tiger for a while. I wiped out all of the macos stuff to install Fedora.
Upon the first reboot, first I saw an alternating folder icon and question mark. Then I briefly saw a white on black text menu asking if I wanted to boot Fedora, boot off of the CD, off of the network, or go to open firmware. If I didn't do anything, it would begin looping with some sort of "DEFAULT" message and stop responding. The tab key would stop it at this menu.
I managed to manually boot linux by either setting the boot-device to "hd:\yaboot" and then run mac-boot, or I could just type "boot hd:\yaboot". Once at the yamon prompt, I could type "linux single" and get single user mode. Here at least, I could change the yaboot.conf settings, then run ybin to write the changes to the boot partition.
As I understand, the ofboot.b file is there to allow the graphical chooser to show a fedora partition to boot from. Holding down the option key to choose a boot device from icons didn't do anything. I assume this is either because of my particular OF version (3.1.1 Powermac1,2) and my bootrom version (1.2f2). It could also be some glitch since MacOSX isn't present.
The default setting for "boot-device" in OpenFirmware was "disk@0:2,\\:tbxi". BTW: the devalias "hd" corresponded to the same disk. The first (and only) file of type tbxi on the boot partition was ofboot.b. In order to jump around ofboot.b, I turned off the magicboot entry in the yaboot.conf, and re-ran mkofboot to have ofboot.b removed, and have yaboot changed to type tbxi. I rebooted, but booting failed without manual intervention at the OF prompt. I even tried changing the boot-device to "hd:,\:txbi" to ensure OF didn't look for a macintosh system folder with no luck.
It ended up simpler to just set the boot-device to "hd:\yaboot", and also to force the "nonvram" setting in yaboot.conf to stop the system from overwriting my changes to OF.
I guess any question of mine really is, did I just go the long and hard way to make this work, or could there have been something simpler?