At  one can read that there is buildroot support, where can I find the defconfig ?
There existed a configuration for Rock Pi 4 for a short time, but not for Rock Pi S.
Support for Rock Pi 4 was added  after release 2019.05, but was removed  before the next release due to inconsistencies in the build.
@luc, thanks, but obviously not what I was looking for.
Rock Pi 4 is not only a different board, but a different processor, too.
In  it clearly states:
Debian and buildroot is currently supported on ROCK Pi S
So someone has to have a valid defconfig for it, I just wonder where to find it.
I’m interested too.
Having a 256MB model, I would much prefer cross-compiling with buildroot.