Re: patch: shadowfb also for non-EFI boots

[Ignatios Souvatzis <is%netbsd.org@localhost>]

On Thu, Apr 09, 2026 at 12:28:12AM +0000, RVP wrote:
> On Wed, 8 Apr 2026, is%netbsd.org@localhost wrote:
> 
> > I've tested this on the machine in question, netbsd10.1 userland,
> > with netbsd10, netbsd11 and netbsd-11.99.5 kernels (with this patch),
> > and on a machine with intel graphics.
> > 
> 
> There're 2 issues (both fairly minor) with enabling the shadow FB:
> 
> 1. Addtl. mem. used for it (20+ MB easily for a 4K resolution).

... you wouldn't want to run that resolution on a memory-starved machine
anyway. At least I wouldn't. Maybe shadowfb could be a build option?

> 2. Screen-artefacts on the console after paging with Shift-PgUp/PgDn.

This is a bug I can confirm. Should also happen on UEFI boot (I'll look
up a machine with that and test to confirm), and from the behaviour I
smell too aggressive optimization for empty end of lines that breaks
on scrolling backwards. I'll send a PR if nobody beats me to it, but
this should be independent of the boot method.

I intend to commit within the week, given that nobody else has spoken
up.

	-is