head -r355777: Lack of USB keyboard input during loader

[Mark Millard]

I normally use a PS2 keyboard on a Gigabyte Aorus Gaming 7
(with a ThreadRipper 1950X) during its boot sequence. (Most
use is via ssh once booted.) But I've used a USB keyboard as
well on rare occasion. (Unsure when that last was.)

Well, I happened to try using a USB keyboard for head -r355777
and:

A) The USB keyboard  worked fine for controlling the BIOS
   operation (F12h BIOS version)
B) It was ignored by the loader (so: booted via the timeout)
C) It worked fine for logging-in on the console and later
   activity there

This was repeatable.

By contrast, for the PS2 keyboard, all 3 stages worked fine
when tested, also repeatable.

Overall I can avoid (B) in my context, but I thought that the
status might be of interest to someone.

The -r355777 build is a non-debug build (with symbols).

At this point I've not established any other head -r355777
(or later) instances on any other hardware and I do not
normally use usb keyboards for booting, other than on old
PowerMacs. So I've no evidence for how the issue might
generalize. It may be the weekend (or longer) before I'd
find out.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)