[RFC] How to deal with unchanged images in board status repository?

[Paul Menzel]

Dear coreboot folks,

Thanks to Nico’s introduction of “timeless”/“comparable” builds in
commit 566dd357 (Add option for "timeless" builds) [1], it’s for
example possible to find out, if a commit changed something for a
certain board.
> Builds with BUILD_TIMELESS=1 shall always give a bit identical output
> for stable inputs. This should help verifying that resulting rom files
> stay the same across commits that shouldn't change the outcome.

I started to build my Lenovo X60t with `make BUILD_TIMELESS=1`, and
flashrom now thankfully notifies me, if the resulting image has not
changed. (Of course the configuration, the payloads, and the toolchain
are unchanged here too.)

```
Warning: Chip content is identical to the requested image.
```

So how can we deal with this for our board status repository? Should I
just do the an upload, and git storage model will make sure that this
only takes up little space? On the other hand the coreboot and for
example Linux messages will probably be a little different due to
timing differences.

Another option is to create a symbolic link, and commit that?

Do you have other suggestions? What do you think?

If we agree upon something, the build test systems out there could also
be adapted, and a lot of the REACTS uploads would be just symbolic
links.

Thanks,

Paul

[1] https://review.coreboot.org/13412