Why is hardware peripherals setup / config (e.g. using device tree overlay) hidden from view

[GoGerriko]

@MichaIng thanks for detailed feedback. There is plenty to think about.

@MichaIng

Note that mainline Linux is not designed to compile for a single SBC only (which would be highly inefficient anyway), but the configuration flags/options always define an architecture and SoC family. You can basically see it here in the official Linux sources: …

I decided to go back to basics and this guide concurs with what you are saying. There is plenty to digest here… Device Tree Usage - eLinux.org

@MichaIng

Now since overlays are not maintained within the Linux kernel, there is no guarantee that they are still functional after a major kernel upgrade and Armbian does not have the capabilities to test each overlay with each Linux version on each SBC and in case update them.

I think this is where the “compatible” property plays a role, not only for the board or device but also for the driver (e.g. spi, i2c, pwm etc), to ensure that breaking changes in a new release are handled correctly by an overlay.

@MichaIng

So it is not at all about our scripts, but about the fact that overlays are badly maintained and cannot be relied on.

Hence the dislike for just seeing the compiled .dtbo files in a local folder, without at least a readme file pointing you back to a repository with the script file itself. Otherwise, if and when they do not work, you have no way of determining what the problem is. Anyway, these driver script files are pretty small (<1kB) so they can readily co-exist on a SBC device without causing much bloat.

@MichaIng

Again, it is not at all about the way how overlays are provided, but only about the question whether they are working reliably or not.

Quite right, but actually I was asking a more basic question on setup, on the assumption that all things will just work reliably. Of course, in the real world that is not always the case.

@MichaIng

I hope I made it clear now that there are no “standard” overlays

Agree, but in this post my version of standard overlays simply meant those overlays without requiring additional parameter settings, other than say switching an i2c overlay (e.g. i2c3) status property from it’s default “disabled” to “okay”.

EDIT: Just to clarify here. The way I see it, is that the “.dtb” file, which is the binary created from one of these overlays is the “template” rockchip « dts « boot « arm64 « arch - kernel/git/stable/linux.git - Linux kernel stable tree

What I am really referring to in this post, and also regarding what I referred to as standard overlays, is the “.dtbo” for a specific peripheral.

Anyhow, for now all I’m looking for is guidance on setup.