Re: [Qt5] mkspecs/devices: beagleboard == am335x ?

[Denys Dmytriyenko <denys@ti.com>]

On Sun, Jul 28, 2013 at 03:18:05AM +1200, Christian Gagneraud wrote:
> On 07/27/2013 02:20 PM, Sundareson, Prabindh wrote:
> >The device approach is useful for adding platform specific hooks for
> >eglfs via EGLFS_PLATFORM_HOOKS_SOURCES, so it is a good thing. So it is
> >more of a convenience/cleaner way, than anything related to performance.
> >
> 
> I do agree with Dennys about the compiler flags, yocto knows what
> are the best flags for the machine/device.
> What is nice with the device file approach is the specification for
> OpenGL includes, libs, QPA and the EGLFS hooks as well.
> Basically I like the fact that all the OpenGL "mess" is sorted out
> in one place (when it comes to compilation).
> Interesting examples are the Rasberry Pi [1] and Freescale i.mx6 [2].
> 
> when considering Qt alone (out of Yocto/OE), I think as a SoC
> vendor, it is the best way to make sure your users get the best of
> Qt5/OpenGL, and very easily according to [3] (not tested).
> 
> 
> When it comes to Yocto, I didn't see any easy way for meta-bsp to
> tell meta-qt5 how to configure/build qt5 w/ OpenGL support.
> It seems to me that the only way is through the .bbappend, in qtbase.inc:
> [...]
> # if you want to enable egl/gles2 in your .bbappend, don't forget to
> add right dependencies, e.g.
> # GL_DEPENDS = "virtual/libgles2 virtual/egl"
> # QT_GLFLAGS = "-opengl es2 -eglfs"
> GL_DEPENDS ?= "virtual/libgl"
> QT_GLFLAGS ?= "-opengl"
> [...]
> 
> Could/should this be used by the meta-ti layer?
> 
> I spent some time recently going through meta-qt5 recently (as well
> as the qt4 stuff), I even tried an alternative configure/method, so
> far unsuccessfully. My feeling is that meta-qt5 tries to adapt qt5
> to OE, I think it should be done the other way around, that's my
> very personal view.
> 
> I really would like to see a Yocto Qt5 SDK one of these days.
> 
> Prabindh, could you tell more about the status of Qt5/OpenGL for TI
> SoCs, what about this commit [4]? Is it possible to build within
> Yocto Qt5 w/ OpenGL support for AM335x platforms?

Have you seen this thread:
http://thread.gmane.org/gmane.linux.embedded.yocto.meta-ti/2139

-- 
Denys


> [1] http://qt.gitorious.org/qt/qtbase/trees/stable/mkspecs/devices/linux-rasp-pi-g++
> [2] http://qt.gitorious.org/qt/qtbase/trees/stable/mkspecs/devices/linux-imx6-g++
> [3] http://blog.qt.digia.com/blog/2012/04/13/cross-compiling-qt-for-the-masses/
> [4] https://github.com/prabindh/meta-qt5/commit/c8129fb5057f9254c773f82d2fdbd85d9c56410a
> 
> 
> >
> >regards
> >Prabindh
> >________________________________________
> >From: meta-ti-bounces@yoctoproject.org [meta-ti-bounces@yoctoproject.org] on behalf of Dmytriyenko, Denys
> >Sent: Saturday, July 27, 2013 2:36 AM
> >To: Christian Gagneraud
> >Cc: meta-ti@yoctoproject.org
> >Subject: Re: [meta-ti] [Qt5] mkspecs/devices: beagleboard == am335x ?
> >
> >On Fri, Jul 26, 2013 at 10:45:02AM +1200, Christian Gagneraud wrote:
> >>Hi there,
> >>
> >>In qtbase sources, there are a couple of "device" definitions files,
> >>according to [1], this greatly help cross-compiling qt5.
> >>This device file specify things for CPU and GPU optimisations. So
> >>basically these files are tightly coupled with BSP providers.
> >>
> >>One of them is linux-beagleboard-g++ [2], is it appropriate to use
> >>this one for AM335x based platform as well?
> >>
> >>The meta-qt5 layer doesn't seem to use this feature, but if it did,
> >>would this device config files help to get an optimised Qt5 build
> >>for TI SoCs? Especially, would that help to get OpenGL stuff sorted
> >>out?
> >>
> >>Regards,
> >>Chris
> >>
> >>[1] http://blog.qt.digia.com/blog/2012/04/13/cross-compiling-qt-for-the-masses/
> >>[2] https://qt.gitorious.org/qt/qtbase/trees/stable/mkspecs/devices/linux-beagleboard-g++
> >
> >Chris,
> >
> >Looking at those files shows very basic compiler optimization flags being set,
> >-march, -mtune, -mfpu etc. I don't see any GL or GPU specifics in there. It
> >also hardcodes things like soft-fp, which is not good. All this stuff is
> >alredy taken care of by the build framework and I'm sure meta-qt5, like the
> >old qt4, sets all the right COMPILER_FLAGS to get the most performance from
> >the target CPU.
> >
> >--
> >Denys
> >_______________________________________________
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> >meta-ti@yoctoproject.org
> >https://lists.yoctoproject.org/listinfo/meta-ti
> >
>