Booting Unmatched without the console USB connected

HiFive Unmatched
1

It seems that the Unmatched won’t boot unless the serial console is connected to something. I have a GPU on it so I no longer need the serial console and would like to boot without it. I see no u-boot logs or anything when I attempt to boot without it connected, which makes me think it’s happening at the firmware level. Is it possible to boot without anything connected to the console USB?

A few other things I’ve tried:

  • Plugging in the console USB 2 seconds after boot: this works!
  • Plugging in the console USB 7 seconds after boot: this leads to a u-boot shell after connecting it and sending keypresses.
  • Plugging the console USB into one of the USB-A ports on the Unmatched: this also works.

Other details:

  • The board is version 3 (HF105-ASSY-3A0)
  • Operating system is Ubuntu 21.04
  • GPU is AMD RX580 and works fine when USB console is connected
1 Like
2

This is a known problem on pre-production version boards (HF105-ASSY-3A0) sent to eco-system partners. There has been a minor hardware change which fixes this issue.

The production version boards (HF105-ASSY-3B0) shipped to our distributors for end customers have the required change and shouldn’t see this issue on the boards they receive.

3

Thanks for the update! In that case I’ll hack something simple together to keep plugged into it.