On 2019-09-20 6:03 a.m., Mark Kettenis wrote:
One thing to look at is whether (voltage) regulators and/or clocks are set up right...
Thanks, Mark. This is helpful.
But I believe the Linux kernel doesn't trust the bootloader and will configure such a regulator anyway.
This is my assumption right now as well, that Linux is itself configuring the RK3328 "correctly" and either the U-Boot TPL or the NetBSD kernel needs to be updated to do the same thing.
I'm going to grab the Linux source and see if I can spot anything it does at startup that's missing from the TPL.
Using the U=boot "dm" commands you can check whether drivers for various regulators are enabled.
I tried capturing the output of these commands when each TPL is used and comparing them. Unfortunately nothing jumps out: After booting with U-Boot's TPL "dm tree" shows additional entries for the S/PDIF and MMC controllers, and when booting with Rockchip's TPL a (possibly spurious) "Initializing UCLASS_EFI" message is output, but otherwise they're the same.
I've attached the two capture logs in case anyone is curious.