Power Mac G5 - unable to boot into completed installl

lukezenoob

It has come to my attention that this G5 will not boot from external devices, so i sacrificed the 2nd hard drive on this as the root filesystem, sure, no problem, spend another 9 hours compiling kernel, this is expected.

The best thing is that Yaboot shows up in the boot menu when holding down ALT, so we're getting somewhere, only issue is that when i do select that second hard drive, the graphics gets weird and then kicks me back into the boot menu.

Here is my current yaboot.conf. fstab doesn't include a boot partition.

exuberantmonkey · n00b Joined: 09 Apr 2023 Posts: 19

You probably either gave up or have it working by now, but just in case - I ran into the same problems using the PPC64 handbook instructions which appear to be out of date.

Firstly, I could not get yaboot to work, even after reformatting my root partition as ext3 (I read something about yaboot not supporting on ext4). I tried all sorts of things. For one configuration I got as far as a black screen with messages from yaboot, but then it could not find my root partion, no matter what.

Then I found this link via the forums:
[url]https://wiki.gentoo.org/wiki/GRUB_on_Open_Firmware_(PowerPC)[/url]

Grub was able to find my boot partition with the kernel, once I used "boot hd:3,\grub\grub.img" instead of "boot &device;,\grub\grub.img" in the CHRP script (the latter did not work for me). I should probably update "hd:3" to the full open firmware path at some point (i.e., path reported by "ofpath /dev/sda3").

To use grub with PPC64 you need an ext2 boot partition, and of course the handbook tells you not to create one (since it is written to use yaboot). Rather than start from scratch I deleted my swap partition, created a 500 Mb boot partition and then a new smaller swap partition (root now being sda5, so update fstab accordingly).

The next problem is the kernel generated by genkernel on PPC64. Grub finds it but then boot fails with something like "cannot boot a kdump kernel from of" and a memory access violation. Forums to the rescue again -- build the kernel manually, first using "make g5_defconfig" and then the manual kernel build instructions and initramfs etc. Re-run grub-mkconfig and set boot device with nvram tool and voila. She finally boots!

Now if only those fans would stop blowing full on ...

Atha · Apprentice Joined: 22 Sep 2004 Posts: 243

Atha · Apprentice Joined: 22 Sep 2004 Posts: 243

exuberantmonkey · n00b Joined: 09 Apr 2023 Posts: 19

Thanks for the tips. My two G5s are actually both power macs.

I gave up on yaboot and got boot working with grub, though I did snag the penguin icon for the ofboot.b CHRP script from yaboot -- looks better and further reduces file size on a rather tiny NWBB partition.

As for the fans - yes, I just had to enable all the windfarm options and it worked.

One other thing I noticed was a difference in the path reported by yaboot's ofpath tool vs. what is listed by "devalias" when booting the G5 into open firmware with command-option-O-F. The path reported by ofpath includes additional details, like the "@0,f2000000" after "/ht", and "@c" after "k2-sata-root".

I have two G5s, different models. On one, using the path from the ofpath tool works in the CHRP script. However, for my second G5, that path doesn't work. Then I noticed the discrepancy in the paths reported by ofpath vs. devalias, and for one last attempt I tried the less decorated path, as reported by open firmware's devalias, in the CHRP script. Then she booted.