[coreboot] PC Engines apu2 booting broken

[Kyösti Mälkki]

On Sun, Oct 1, 2017 at 8:11 PM, Piotr Król <piotr.krol at 3mdeb.com> wrote:
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> Hi all,
> PC Engines apu2 (and probably apu1) not booting on recent master. I
> bisected problem to: d4955f0ade18cafde4a3ea20885eb9fbdc5b4514
>
> AGESA: Move API interface under drivers/
>

My fault, see: https://review.coreboot.org/21840

That was insufficient testing on my side, I blame too much pending
work in the review queues spanning couple branches...  I mostly test
only without BINARYPI_LEGACY_WRAPPER, and some of that work has still
not landed in gerrit.

> I'm not sure if some config options are missing. I tried to select
> DRIVERS_AMD_PI and CPU_AMD_PI in Kconfig, but those not help.

Once you have bisected to an offending commit, you can do builds that
strips away all the revision hashes:

  abuild --timeless -at pcengines/apu2
  diff -qr build-ok/ build-fail/

The list of just the .o files is still a long one, but two further
things you can do here: Strip debug symbols from .o files, and define
ASSERT() without __FILE__ or __LINE__. If you know the commit was
supposed to create a binary identical image, this is one way to
pinpoint where the difference is.

This approach has saved the day before when AGESA includes have gone crazy.

Kyösti