On Mon, Apr 08, 2024 at 11:41:10AM -0500, vindicator wrote:

Is u-boot capable of selecting the correct DTB in a UKI during boot?

I saw "doc/README.multi-dtb-fit", which at least somewhat addresses what I'm looking for I think, but I'm not sure if that will relate directly with executing a UKI that has multiple DTBs...

For my one board, I was working on building a workable "tinyconfig" kernel, but then also had the thought to maybe also build another "allyesconfig" kernel (one time) so I can figure out everything that gets used for ANY board (supported for $ARCH). Then another thought came after that, that maybe I could pile in all of the DTBs the kernel supports into a UKI (via "ukify"), which is where I came across https://github.com/systemd/systemd/issues/31946 (convenient timing being so recent).

So it looks like my thinking is "doable", but just hasn't been done yet in "ukify", and I'd thought I'd check here if there's anything that needs to be done from u-boot's end as well.

Sorry for the delay in replying here. Yes, it's possible to have U-Boot select the appropriate device tree in a FIT image that contains multiple device trees.