>> I did manage to get the rockchip.usb_uart with a hacked up USB cable to
>> produce a serial console for debugging and actually seeing the kernel
>> logs rather than them scrolling pass the screen only to give a kernel
>> panic.
>>
>>   (kernel-arguments '("console=ttyS2,115200" "rockchip.usb_uart"))
>
> To be clear, this feature doesn't actually make a serial console over
> USB, it somehow "rewires" one of the USB ports to have a ground, rx and
> tx serial-ttl pinout. So you pretty much need a custom USB-A plug and
> solder/crimp the bare wires to a serial-ttl adapter. Slightly more
> details in Documentation/admin-guide/kernel-parameters.txt.

I made one of these cables, but wasn’t sure if it worked, and I didn’t
know what settings I needed in the kernel to make it work.  Thanks for
figuring this out!  I hope that it gives you a nicer way to debug the
kernel when it boots to a white screen.

Thanks for testing and working on this.


-- Tim