Using EGL drivers in Weston without FBDev

[Daniel Stone]

Hi Teemu,

On 23 May 2017 at 05:33, Keskinarkaus, Teemu
<teemu.keskinarkaus at crosscontrol.com> wrote:
> I just ran into this although support was dropped almost a year ago.
>
> Since FBDEV no longer has EGL ‘hackery’ support, what is then the ‘proper’
> way to use EGL drivers?  ie. What way they _should_ be used?
>
> I’m in no way expert in this whole Wayland/Weston/driver thing so that’s why
> I’m asking.
>
> We are currently using Weston in iMX6 based HW and NXP currently has only
> EGL/FBdev drivers available that’s why I ran to problems with Wayland/Weston
> when trying to upgrade to Weston 2.0.

The recommended way is to use EGL on top of KMS (kernel modesetting),
the combination of which is called GBM. This is what's implemented by
Mesa, and also several other drivers including ARM Mali.

The last time I saw NXP i.MX code for Weston, it was a fork of Weston
using their own API for rendering and buffer management. I don't know
if this ever got ported forward to newer versions, so you'd probably
be needing to use their tree anyway. I know this isn't the advice you
were hoping to get, but I would strongly recommend contacting NXP and
asking them to support KMS and GBM like everyone else.

The good news is that the 'Etnaviv' and imx-drm drivers inside Mesa
and the mainline Linux kernel work just fine, so if you use very new
versions of Mesa and the kernel, there should be no need to run NXP's
fork of Weston and their EGL drivers.

Cheers,
Daniel