Boot failure with ppc64 port on iMacs G5

[Michael Ellerman]

John Paul Adrian Glaubitz <glaubitz at physik.fu-berlin.de> writes:
> On Tue, 2024-02-20 at 04:16 +0100, tuxayo wrote:
>> I tried snapshots/2024-01-31/debian-12.0.0-ppc64-NETINST-1.iso
>> 
>> And was able to start booting from usb with:
>> boot usb0/disk at 1:,\boot\grub\powerpc.elf
>> (typed in Open Firmware shell)
>> (usb0 is the top port)
>> 
>> Grub worked, and then I tried default install (the 1st option) and it 
>> started loading during like 2 minutes.
>> And then it got stuck with some superposition of the messages
>> smp_core99_probe
>> and
>> the stuff before
>> DO-QUIESCE finisedBooting Linux via __start() @ 0x0000000002090000 ...
>
> There seems to be a regression in the kernel which affects PowerPC 970 machines,
> i.e. PowerMac G5 CPUs. The issue needs to be bisected and reported upstream.

I have a quad G5 that is booting mainline happily.

I used to have an iMac G5 but it died.

> If you have the time, I would really appreciate if you could test the various
> snapshots and let me know which kernel is the first to not work. I expect that
> the breakage occurred somewhere around kernel 6.3 or so.

Can someone send the .config for the kernel in question? I could try
that on my machine here.

cheers