Re: PowerBook G3 Wallstreet Hang Using Debian Kernel
Hi Stan,
Thanks for the update. I'll try your config and see how it works. My
WallStreet is actually 1024x768, 266MHz, 512MiB, just like yours.
Although, with no module support, I wonder if it is better just to stick
with kernel 6.3, since it appears to work fine? I seem to have no issue
running the same latest packages as on my G4, and am frankly unfamiliar
with how much of an issue it will be to continue using an outdated kernel.
Did you ever end up submitting that bug report on the Linux PPC dev
mailing list? I would do it myself, but clearly you have better
knowledge of the issue (and I wouldn't want to steal your cred). I saw
you posted a report on the Pismo, but if you posted one on the
WallStreet too I must've missed it.
On 10/28/25 10:43 AM, Stan Johnson wrote:
Hi Cedar,
I haven't been able to determine a reason for the hang of Debian's
default kernel/initrd combination (6.16.9+deb14-powerpc) on the
PowerPC PowerBook G3 Series laptop (Wallstreet).
Finn Thain (cc'ed on this message) found a bug that was causing video
to not work correctly (see "https://lkml.org/lkml/2025/10/9/639";).
Unfortunately, as it turns out, that bug was not related to the Debian
hang.
I'm able to reproduce the hang on my Wallstreet (266 MHz, 512 MiB)
using an updated Debian SID and the Debian kernel/initrd. However, the
hang doesn't happen on my PowerBook Lombard or Pismo. As you've
reported, the symptoms are that the screen goes blank and the
backlight stays on, and the system freezes (Linux doesn't boot).
And there's no output from the serial port. It's possible that there's
an issue with BootX not being able to handle large initrd.img files
(initrd.img-6.16.9+deb14-powerpc is over 40 MB), but I really have no
idea. I tried adjusting the memory for BootX in Mac OS 9 to 64 MiB,
but the hang persists. I also tried adding sccdbg and initcall_debug
to the kernel command line, as suggested by Finn, but neither
generated any serial output, which suggests (to me) an issue with
BootX. I have not found any combination of BootX options that will
produce serial output.
And I haven't been able to test the effect of config file changes to
Debian's kernel because config-6.16.9+deb14-powerpc does not produce
the kernel and modules that Debian distributes (the new vmlinux is
over 200 MB, modules are over 300 MB, bZimage is around 9 MB). I could
start stipping out debugging and other features, but that would make
the kernel quite different. Without being able to reproduce Debian's
kernel, I'm stuck.
Using the attached config-6.17.5-pmac, which is a limited config file
that includes only the options that are needed for most PowerPC G3 and
earlier PowerPC PowerBooks, with no module support, everything works
as expected, with both "video=ofonly" (check "No video driver" with no
extra command line options), or the usual
"video=atyfb:vmode:14,cmode:32,mclk:71" for my 1024x768 Wallstreet.
For your 800x600 Wallstreet, "video=atyfb:vmode:10,cmode:32" should
work. It should also work to check "No video driver" in BootX with no
extra command line options in BootX.
I'm using kernel 6.17.5 from www.kernel.org, but the latest mainline
kernels also work.
-Stan
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