Hi Darren,
I don't have a iMac G5 to tinker with, but according to your description
it sounds like the OFfb console display seems fine up until the nouveau
module loads and after the nouveau console handover occurs, the display
seems to get distorted on the built-in LCD afterwards. Have i correctly
understood your issue?
The kernel versions that you tried (3.18.16 & 4.5.0-rc2) shouldn't have
an issue extracting the DCB from the nVidia FCODE rom in the device
tree. But not to say that there isn't a specific issue in your
particular case...
A complete dmesg log from kernel version 4.5.0-rc2 would be handy and
might possibly give some clues.
Also if possible, please attach an image to see what actual distortion
you are seeing on the built in LCD?
Perhaps nouveau cannot detect what is the correct output type to use and
gets confused or can't read a valid EDID and screws up the display
timing for the DFP output which should drive the built in LCD of the
iMac G5..... No idea, perhaps the logs will give more info.
Out of curiosity, can you connect an external display to an iMac G5? If
so, please try to see what happens.
Good luck!
Cheers,
Peter
