U-Boot Concept Tree Proposal

[Simon Glass]

Dear U-Boot Contributors,

I would like to introduce the U-Boot Concept tree along with a few thoughts
on its role in U-Boot.

By way of background, I have been a contributor for about 15 years - around
10k commits and countless reviews. I have introduced many innovations into
the project: e.g. sandbox, device tree, C test infrastructure, Binman,
standard boot. Of course I could not have done any of this without the
U-Boot community (nor would there be any point).

As the U-Boot project has matured, the demands for mainline stability and
rigorous review have created a natural friction for landing complex,
large-scale feature and refactoring series at the necessary pace. This
structural reality, which has slowed the adoption of ambitious efforts like
bootstd, VBE, xPL [1], and CI-connected hardware labs, is what the Concept
tree is designed to alleviate.

I strongly believe that projects must evolve in order to stay relevant in
the long term. This includes code-refactoring, new features and subsystems,
along with migration of old code to use them.  A look back at the U-Boot of
2010 shows how far the project has come. I don't think anyone would still
be using U-Boot if it had not evolved.

I have set up a 'Concept' tree, a possible future for U-Boot, as a way to
regain the old pace of innovation. This environment is a proving ground for
new features where we maintain a lower bar for risk tolerance and
completeness. We will accept partial and speculative features, provided the
underlying code remains robust and of high quality, with the shared
understanding that features may be dropped if they do not prove beneficial.

Another difference is AI. I believe that AI is the next step on from
compilers, which also took a long time to produce good code and find
acceptance. The Concept tree welcomes (and encourages) high-quality AI
contributions and reviews. It accepts PRs and allows reviews on PRs or the
mailing list. It relies 99% on automated tests (sandbox, QEMU and labs) so
sets a high bar for testing. It uses a separate Gitlab instance for now and
of course uses a separate mailing list and Patchwork project to avoid
cluttering the main list. Concept runs an AI-powered cherry-picker so that
it keeps up with mainline. In no sense is it operated as a fork.

Once features are landed and functional in Concept I hope that many will
find their way to mainline, although inevitably some rework will be needed.

I recognise that introducing a new 'Concept' tree might initially cause
confusion or concern. This is an invitation to work together to define its
role. I welcome all feedback - positive or negative - here on the mailing
list, privately, or on irc. Let’s discuss how this initiative can help
U-Boot remain the defining firmware for the 2030s.

[1]
https://lore.kernel.org/u-boot/CAFLszTg6sKpZ1yP3Pjgk9_Fx3MOh=ieT2oaHfgLf3_nC+xXA9g@mail.gmail.com/

Concept tree:
                       :
                       ::
                     ...:::.
                 ::  :. -
           .   ::::::-  - ::. ..
          .:: .:      -==  =.:.
        ::.- ::::. ::. :=:. ::::
  ::. ::   =..  :.-::: =:
    .:-:-. -.::  ::=-:=:
  ::::::=.  -.::   ===:       ::.
    ::.:::=::=:   -===:--==-::--::
      :.    :-=-.:==:.   .:  ::
               ===:       ::  :
               ==:
               ==
              :==
              -==:
              -+=:
              =++=.
             .-===: