boot loop since 5.17.6

[Thomas Sattler <sattler@med.uni-frankfurt.de>]

Hi there ...

summary: boot loop after upgrading from 5.17.5 to 5.17.6

I have a Gentoo Desktop where I was successfully running a self
compiled vanilla 5.17.5 kernel. After upgrading to 5.17.12 the
machine was unable to boot: lilo loads the kernel and the intel
microcode 20220510_p20220508 (/boot/intel-uc.img) as an initrd.
Then the monitor turns black and a few moments later the BIOS
logo is shown, followed by lilo.


As there was a recent microcode upgrade I first tried to boot
without it. But that didn't help.

Then I tried to boot other already compiled but not yet booted
kernels 5.17.9 and 5.17.6 without any success. Booting the old
5.17.5 still worked. So I compiled 5.18.1 but that also was
unable to boot.


Then I tried to do a "manual bisecting" with patch-5.17.5-6
and found that the machine is still booting with 197 of 209
diffs applied.

After applying "patch-5.17.5-6.part198.patch" compilation is
broken. Still after applying "patch-5.17.5-6.part199.patch".
After applying "patch-5.17.5-6.part200.patch", compilation
works again but the resulting kernel now fails to boot.


It is an (up to date) Gentoo System, installed ~15 years
ago, running a 64Bit kernel with a 32Bit userland. The
hardware is newer then the installation (i5-7400).

I have to mention that the machine is in a remote location.
With lilo allowing a "default kernel" as well as a kernel
to be booted "just once", I was able to try the above from
remote.

Thomas