How to have accelerated graphics with Intel Celeron J1800 (Bay Trail) ?

[Juan Ramón Molina Menor]

> Hello,
>
> I recently bought a fanless PC based on Intel Celeron J1800 and its
> embedded graphics, and now I'm asking the stupid question of how to
> make graphics acceleration work.
>
> As far as I can tell, this chip belongs to the microarchitecture
> codenamed "Bay Trail", which sits between "Ivy Bridge" and "Haswell".
> That's circa 2013.
>
> According tohttps://wiki.freebsd.org/Graphics  "Ivy Bridge" is already
> well supported, while "Haswell" should be in 11.0, so I was reasonably
> hopeful to see my "Bay Trail" work.
>
> Going with a 10.3-RELEASE, I `pkg install`ed minimal graphics stuff,
> including xf86-video-intel, but it didn't found any screen.
> xf86-video-vesa does work fine but without acceleration.
>
> So I assumed that "Ivy Bridge" was the last supported microarchitecture,
> and that my "Bay Trail" was too recent for the driver.
>
> So I took the 11.0-BETA1 recently released, and did the same thing (I
> was a bit surprised to find a pkg repository, but I won't complain), but
> I was to see the same results. Even xf86-driver-scfb cannot find a
> screen.
>
> So my question is, what can I do now? Is my hardware definitely
> unsupported? Is there something special to do to enable the new i915?
>
> If you have the patience to cut-and-paste or link to instruction for
> scfb, I would welcome it was well, but I admit not having done much
> research (I don't even know whether `kern.vty` at "vt" means it should
> work or it shouldn't) so I would understand if you let me search more on
> it before helping in that direction.
>
>
> Thanks in advance for your help,
> Natasha

Hi Natasha.

Matthew Macy has done a lot of work recently to support relatively 
recent Intel GPUs in CURRENT. The development branch is in GitHub, I 
suggest you to start here:
https://github.com/FreeBSDDesktop/freebsd-base-graphics/wiki

As for your Bay Trail chip, there is an open bug:
https://github.com/FreeBSDDesktop/freebsd-base-graphics/issues/6

Concerning the scfb driver, I’ve used it with success (but only in a 
Haswell chip) by just adding the following lines to xorg.conf:

Section "Device"
      Identifier "Generic FB"
      Driver "scfb"
#    Option "NoAccel" "True" # Both work, test it
EndSection

Hope it helps,
Juan