From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Sun, 30 Mar 2014 17:21:28 +0200 Subject: [Buildroot] qt5, eglfs and xcb In-Reply-To: <5338207F.9010807@gmail.com> References: <5338207F.9010807@gmail.com> Message-ID: <20140330172128.06f1d5d2@skate> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Dear Marco Trapanese, On Sun, 30 Mar 2014 15:47:43 +0200, Marco Trapanese wrote: > when you try to build qt5 with the X support (xcb), selecting one of the > following modules: qtquick*, qt5declarative, qt5graphicaleffects and > qt5multimedia, leads to force the selection of the eglfs support. > > After three days of build failures (due to the same constants defined > both from xbc and eglfs) I asked an aid to a company which offer a > technical support about Qt. The says only qtquick2 requires the opengl > acceleration and this one is provided also from xbc. This is not quite correct (even though the general problem you raise actually exists). First, it's actually qt5declarative that requires OpenGL (or OpenGL ES) support, and qt5quick1 depends on qt5declarative. Same for qt5graphicaleffects, it depends on qt5declarative. Moreover, under X.org, having XCB is clearly not sufficient to get OpenGL support. XCB is merely a modern implementation of libX11, which allows to talk to the X server to do some rendering, but not direct, OpenGL rendering. > So it shouldn't required at all the eglfs plugin if you're using X. This is correct. eglfs is only needed for non-X.org situations. > Please, might you verify this? > If they are right, could you fix the dependencies so we can build a > working buildroot image with Qt5 and xcb? As explained above, this requires more than just XCB, contrary to what the company you requested support from is claiming. You need an OpenGL implementation that works under X.org, and this implementation is usually Mesa. And the support for making Mesa recognized as a proper OpenGL implementation has only been merged since yesterday, and is not yet completely ready. It would certainly be interesting to fix this in Buildroot and allow Qt5 to build for X.org with OpenGL support. But if you want this to happen, you should either: 1) Do it yourself. 2) Wait for someone else to do it, but then you can't expect any particular deadline or guarantees. It may be something that will get done this summer as part of the Google Summer of Code. 3) Hire a third party to do it. Actually, it's a little bit strange that you've asked a company who isn't able to fix the problem in Buildroot, rather than a company that actually is able to do it. BTW, what is your hardware platform? What type of graphics hardware are you using? What X.org driver are you using? Anyway, thanks for the report, this is definitely something that should be improved. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com