I install MOS2.6 and X 10.5.6 at macmini and load MOS set to default. I do upgrade to MOS 3.0 and no problem. With PowerBook 1,5G 15" i change : setenv boot-command boot hd:4,\\bootinfo.txt and i see gray screen. restore to mac-boot do load OSX default. What means ?
Quite likely the partition number needs to be adjusted. Try to type dir hd:4,\ and see if the bootinfo.txt file is there - if not, you need to adjust the number.
my opinion: use YABOOT; in these way you don't need to change the OpenFirware. If you need to change something, you'll edit only the yaboot config file
@jacadcaps In my case the "reset-all" command did not work on the powerbook (th new env variable was not stored!) while a "shut-down" worked! I don't know why.