install/58288: 10.0 (final) sysinst terminated after "Window too short..." message on a EFI netbook EeePC

[radim.lysek%atlas.cz@localhost]

>Number:         58288
>Category:       install
>Synopsis:       10.0 (final) sysinst terminated after "Window too short..." message on a EFI netbook EeePC
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon May 27 11:20:00 +0000 2024
>Originator:     Radim Lysek
>Release:        10.0 final
>Organization:
Atelier Lysek, Bruntal, Czechia
>Environment:
>Description:
Installation of 10.0 release amd64 on a EeePC 1015BX_BL121S failed. By using a EFI boot item, installation ends identically to PR #58279 (blank screen, white block up left). By using a Legacy (BIOS?) EFI boot item, hw detection phase runs OK in 40x25 text mode to the point of (usually) switching to HR text, then sysinst blue bkg screen with selecting od installation messages language appears in a 8-bit HomeComputer look (63x19?columns/rows) drawing only uuper part of this first install screen; after choosing messages in English, installer go to the next screen, that - in the same resolution (with showing lower part of language selecting screen) - stated: "Window too short (m->h 2, m->numopts 33, exithadd 8, y 12, max_lines 18, hadd 4) for menu "Keyboard type"; [NL] sysinst terminated. [NL] To return to the installer, quit this shell by typing 'exit' or CtrlD [NL] #".
For further information there is a dmsg output on working NetBSD 9.4 on this netbook, and a photo of failed 10.0 sysinst screen - if requested i am ready to send via e-mail.
>How-To-Repeat:
On a EeePC 1015BX_BL121S with NetBSD 9.3 create on a integrated SD card reader (sd0) new installation medium (dd if=NetBSD-10.0-amd64-install.img of /dev/rsd0d obs=2m) and reboot with EFI boot selection: EFI SD media install fails with "GOP setup failed", repeated EFI boot select "SD Media" (without EFI) runs OK to the point of sysinst start: screen appears with too low resolution.
>Fix: