The --verbose mode is impractical

[gendx]

Expected Behavior

OpenSK on an nRF52840-DK with the --verbose option enabled can be registered on https://webauthn.io/.

Actual Behavior

Currently, the --verbose option triggers many syscalls to write to the console. This slows down the whole app, making it impractical. For example, USB packets are dropped when trying to register on https://webauthn.io/ in --verbose mode on an nRF52840-DK, so registration fails altogether in this scenario.

Steps to Reproduce the Problem

1. Flash OpenSK on a nRF52840-DK with --verbose enabled $ ./deploy.py --board nrf52840dk --opensk --panic-console --verbose.
2. Visit https://webauthn.io/ and start the registration flow.
3. Look at the console output and observe unexpected USB packets.
4. Look at the webpage and observe that the registration flow hangs.

Specifications

• Version: 284b142
• Platform: Linux

[gendx]

Unblocking as tock/tock#1697 was fixed upstream. The fix pull request is in #87.