port-amd64/55000: NetBSD-9.0-amd64-uefi-install.img doesn't boot on Panasonic CF-NX3

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

>Number:         55000
>Category:       port-amd64
>Synopsis:       NetBSD-9.0-amd64-uefi-install.img doesn't boot on Panasonic CF-NX3
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Feb 22 03:00:01 +0000 2020
>Originator:     Izumi Tsutsui
>Release:        NetBSD 9.0
>Organization:
>Environment:
System: NetBSD mirage 9.0 NetBSD 9.0 (GENERIC) #0: Fri Feb 14 00:06:28 UTC 2020 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC i386
Architecture: i386
Machine: i386
>Description:
NetBSD-9.0-amd64-uefi-install.img doesn't boot on Panasonic Let's Note
CF-NX3. The boot menu appears, but after the boot menu screen is cleared
a cursor is printed at left-top and nothing proceeds.

Note NetBSD-9.0_RC1-amd64-uefi-install.img worked, and replacing
EFI/bootx64.efi with 9.0_RC1 one also makes the image boot again.

dmesg (with 9.0_RC1 bootx64.uefi) is here:
 https://dmesgd.nycbug.org/index.cgi?do=view&id=5383
 (haudio0 errors are unstable btw)

>How-To-Repeat:
Boot NetBSD-9.0-amd64-uefi-install.img on CF-NX3 in UEFI mode.

>Fix:
No idea.

The machine (which has 1600x900 LCD) doesn't like the following commits
after 9.0_RC1?

 http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/i386/stand/efiboot/eficons.c#rev1.6.6.3
 http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/i386/stand/efiboot/eficons.c#rev1.6.6.2
 http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/i386/stand/efiboot/efiboot.c#rev1.10.2.2