[Interest] Compiling 5.11.2 on a Pi 3B

[Laszlo Agocs]

Enable the experimental VC4 stuff via raspi-config first. The stable option continues to be the traditional Broadcom stack (and no X11). Though perhaps VC4 works better these days than it used to, not sure.


Best regards,

Laszlo

________________________________
From: Interest <interest-bounces+laszlo.agocs=qt.io at qt-project.org> on behalf of Jason H <jhihn at gmx.com>
Sent: Thursday, November 8, 2018 8:19 PM
To: Colin Worth
Cc: interest at qt-project.org
Subject: Re: [Interest] Compiling 5.11.2 on a Pi 3B

I really kicked ha hornets nest. Qt5 compiles on Stretch, but it's got terrible hardware accleration performance (read: none)

There's no difference for me between xcb and eglfs and glxgears is running at 30fps.

$ glxgears -info
GL_RENDERER   = Gallium 0.4 on llvmpipe (LLVM 3.9, 128 bits)
GL_VERSION    = 3.0 Mesa 13.0.6
GL_VENDOR     = VMware, Inc.
...
152 frames in 5.0 seconds = 30.357 FPS

$ qtapp -platform eglfs
libEGL warning: DRI2: failed to authenticate
Unable to query physical screen size, defaulting to 100 dpi.
To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).
Running on a software rasterizer (LLVMpipe), expect limited performance.

What's the best backend to use for Qt on q RPi 3b?

Sent: Thursday, November 08, 2018 at 8:24 AM
From: "Colin Worth" <jlk2144 at gmail.com>
To: interest at qt-project.org
Subject: Re: [Interest] Compiling 5.11.2 on a Pi 3B
I cross-compiled latest Qt 5.10.1 for Raspberry Pi 3B on linux a few months ago. Disabled es2 configure (-no-eglfs -no-egl). Stretch supports an experimental version of OpenGL for the pi, so platform plugin libxcb is okay. This is a good starting point: https://www.raspberrypi.org/forums/viewtopic.php?t=204529. In addition the configure flags, you can also remove references to egl eglfs from qtbase/mkspecs/devices/linux-rasp-pi3-vc4-g++/qmake.conf in the source tree. Hope this helps.

Colin
On Nov 8, 2018, at 7:24 AM, interest-request at qt-project.org<mailto:interest-request at qt-project.org> wrote:

Re: [Interest] Compiling 5.11.2 on a Pi 3B
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