I’m searching for _defconfig and /board files for Radxa Zero for making boot time as minimal as possible. Any help would be appreciate.
Buildroot for Radxa Zero?
I think you are asking for help at wrong place. Try here:
https://bootlin.com/training/buildroot/
https://elinux.org/Experts
Why do you think so? Giving unuseful links to the people and guiding them down the wrong path is a very unprofessional activity and you should be banned for that. Please be kind and respect other users
Why do you ask questions if you know the path?
This is forum if you forget about. Be happy for hints … nobody will do your homework instead of you.
Calm down Igor. I think he is joking.
I haven’t seen anyone working directly with buildroot, but the LibreELEC kernel defconfig could be useful as a starting point:
The LE defconfig contains @@VARIABLES@@ that we sed at compile time, but those are easy to spot and it already removes a lot of the modules that are not really needed for a portable device like the Zero and I see kernel + userspace boot times around 7-8 secs. Boot can be made faster with less modules built-in (more =m) but this will sometimes expose timing issues and I value reliability of boot more than speed.
Also useful is the meta-meson Yocto overlay; this describes the minimum modules needed for Amlogic support in Yocto (applied as an overlay on an existing defconfig):
The links @igorp provided are worth looking at too; Bootlin runs trainings and does regular talks at Linux community events (ELC, Kernel-Recipes, etc.) on boot time kernel optimisation.
Folks let’s keep focusing on the technical stuff and not attacking each other.