[Help]Question about graphics architecture for weson/wayland

[Carsten Haitzler (The Rasterman)]

On Mon, 18 Aug 2014 05:32:41 +0000 Yang Andy <williamyang13 at hotmail.com> said:

> Hi Pekka
> 
> Thank you very much for your reply.
> 
> > > 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.
> 
> If i choose fbdev backend for weston,can i use EFL/Evas and EGL/OpenGL for
> draw graphics? I mean that EGL/OpenGL which implement Software rendering.
> 
> What the difference between
> drm-backend/fbdbin/eolian/impl_generator.c:ev-backend/wayland-backend/x11-backend?

EFL itself doesn't care what the compositor uses for acceleration. efl supports
either software rendering using shm protocol with wayland that SHOULD work
everywhere on all wayland compositors regardless of any driver infra, types,
acceleration etc. - there is also egl + gles2 rendering support for acelerated
rendering. of course compositor will then need to handle drm buffers etc. to
make this work.

> Best regards.
> 
> Andy
> > Date: Thu, 14 Aug 2014 16:57:26 +0300
> > From: ppaalanen at gmail.com
> > To: williamyang13 at hotmail.com
> > CC: wayland-devel at lists.freedesktop.org
> > Subject: Re: [Help]Question about graphics architecture for weson/wayland
> > 
> > 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
>  		 	   		  

-- 
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The Rasterman (Carsten Haitzler)    raster at rasterman.com