On Mon, Jul 23, 2018 at 1:50 AM, Peter Robinson <pbrobinson@gmail.com> wrote:
From the prompt you should be able to types "boot" and it should
continue to boot.

There won't normally be a keyboard on the machine, and I need it to recover from power failures.
 
> followed by lots of garbage (presumably due to baud rate mismatch).

Or the GPS already sending NMEA data.

It's sending NMEA data, but U-Boot sees it as garbage, presumably due to baud rate mismatch.

> Is there any easy way to get U-Boot to not listen to the UART?

Off hand I'm not sure, there was a patch set that did auto enable
based on the what the firmware reported.

I was hoping that there was a configuration option that could be set somewhere (maybe in a text file in the boot partition) to tell U-Boot not to open the serial port at all.