kernel since 5.6 do not boot anymore on Apple PowerBook

[Christophe Leroy]

Hi,

Le 07/07/2020 à 14:58, Giuseppe Sacco a écrit :
> Hello,
> I am testing linux on a quite old hardware, an Apple PowerBook G4
> "Titanium IV". I used to run Debian on this machine, so I upgraded the
> old operating system to the latest software and found that new kernels
> do not boot.
> I rebuilt natively (on the powerbook) a few kernels and found that
> 5.4.50 still works fine, while 5.6.19 and 5.7.7 stop after printing:
> 
> pmac32_cpufreq: registering PowerMac CPU frequency driver
> pmac32_cpufreq: Low: 667 MHz, High: 867 Mhz, Boot: 667 MHz
> 
> no more output is printed. I waited 5 minutes and then powered off the
> machine using the power button. Rebooting with old kernel works.
> 
> So, I am looking for help. How may I better investigate the problem?
> How may I crossbuild the kernel on a faster machine (amd64) in order to
> try git-bisect without waiting ages?
> 

To crossbuild, use cross tools at 
https://mirrors.edge.kernel.org/pub/tools/crosstool/

Can you tell which defconfig you use or provide your .config

Christophe