port-amd64/54606: bootx64.efi does not support consdev

[martin%NetBSD.org@localhost]

>Number:         54606
>Category:       port-amd64
>Synopsis:       bootx64.efi does not support consdev
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Oct 07 10:15:00 +0000 2019
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.15
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD seven-days-to-the-wolves.aprisoft.de 9.99.15 NetBSD 9.99.15 (GENERIC) #312: Wed Oct 2 09:05:05 CEST 2019 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:

The "consdev" command - as documented in boot(8) for x86, and working fine
with the bios bootloader, does not seem to work when using bootx64.efi.
Looks like it is silently ignored.

This is bad when using non server grade hardware (no IPMI or similar) for
server tasks (despite other rumours, most of those boards still have serial
port pins available that can be routed to a slot connector).

>How-To-Repeat:
see above

>Fix:
n/a