[Help]Question about graphics architecture for weson/wayland

[Pekka Paalanen]

On Thu, 14 Aug 2014 08:36:43 +0000
Yang Andy <williamyang13 at hotmail.com> wrote:

> Hi everyone
> 
> When i run 3D application through weston-launch, it failed because the graphics driver is not right.

weston-launch starts weston, you cannot use it to launch something else.

> I have some questions for help.
> 
> 1.Is there any requirement for Hardware(GPU??) / Drivers?

Yes, see hardware enabling at
http://wayland.freedesktop.org/architecture.html

> 2.Is DRM  must for weston(compositor),how to setup DRM?

Weston's DRM backend depends on DRM. Make sure your kernel has a DRM
driver for your graphics chip.

> 3.In order to run weston-launch,do i have to use gpu?

No, you can choose e.g. the fbdev backend for Weston, and so Weston
will run on the /dev/fb, software rendered. No GPU used there in that
sense. Software rendering also means that no application under Weston
can use the GPU for rendering windows.

You can also choose Weston's DRM backend with the software (Pixman)
renderer. That will not use the GPU either, but does need DRM and KMS.

> 4.Does GPU kernel drvier consist of kernel/driver/gpu/xxxx(xxxx.ko??) and of kernel/driver/gpu/drm/xxxx(DRM_xxxx.ko)?

Roughly yes.

> 5.Does user side drvier consist of EGL/OpenGLES?

The user space side of the driver usually implements EGL and OpenGL
(desktop/ES/whatever).

> 6.graphics architecture is Application⇒EGL/OpenGLES/⇒libDRM⇒DRM_xxxx.ko⇒xxxx.ko⇒GPU?

Yes, where EGL/OpenGLES is actually Mesa, since you have libdrm there.
This is specific to the open source drivers.


Thanks,
pq