Re: splash(4) support in vt

On Sat, 18 Mar 2023 22:56:09 +0300
Gleb Popov <arrowd@freebsd.org> wrote:

> Thanks for the pointers!
> 
> It just occurred to me that splash only hides kernel messages, but
> after init(8) starts the image disappears and the textual boot
> sequence is resumed. What are the approaches to solve this? Should we
> handoff rendering to some usermode program? Would that be seamless?

So maybe a R/W tunable that enables/disables screen output is needed.
And init(8) SHALL not change it (leave it for rc.d script or something).

If admins/vendors wants splash kept until desktop environment (mate or
anything admins/vendors want), disable it on /boot/loader.conf and
enable it after DE starts up (and/or X/Wayland is terminated).
Possibly, switching between vtys to forcibly enable the writable
tunable would help. This way, users can use vtys (including console
[vty1]) after startup finishes or crashes, as X is historically tied
to vty9. (Not sure for Wayland, though.)

Without something like that, users cannot see console/vtys after
logging out from DE or switching to any vty while DE is running,
if no serial console is available.

Note that sc worked as expected because sc doesn't touch graphic
flamebuffers at all (pure, hardware text mode), but vt (including
underlying efifb) renders texts to graphics FB, thus breaks splash on
any screen output.

And maybe some changes would be needed to log currently not logged
console outputs. (Driver errors?) Without it, admins has no way to
check such outputs when any error happenes.


-- 
Tomoaki AOKI    <junchoon@dec.sakura.ne.jp>