Netconsole or USB console for TX1 u-boot

Some ARM processors have netconsole or USB (OTG) console implemented for u-boot. How difficult to add netconsole or USB console for TX1?

Serial console (which works great with u-boot) is implemented on J21. See:

The above can be simplified using a 3-wire USB serial UART, but you would use software flow control instead of CTS/DTS.