[TF-A] Build config tool

Hi All,

In TF-A we have a large set of build options (over 90). Dependency and incompatibility checks for these are currently done in the Makefile system. This can be hard to follow and difficult to maintain.

We are investigating if there is a better way to describe the build options in a structured way, handle the dependencies/relations between them, and provide a more user-friendly configuration interface.

A possible good solution for this is Kconfig, more specifically a Python implementation called Kconfiglib [1]. We plan to do more prototyping work in this area.

Any feedback or comments on this topic are welcome.

Regards, Balint

[1] https://github.com/ulfalizer/Kconfiglib