[xenial] QT5 gles support for arm64 architecture

[Chanho Park]

According to the Xenial's build log, it did not build as gles for the arm64 even though it should be built with -opengl es2 option.

> debian/rules
gles2_architectures := armel armhf arm64
ifeq ($(DEB_HOST_ARCH),$(findstring $(DEB_HOST_ARCH), $(gles2_architectures)))
        extra_configure_opts += -opengl es2
else
        extra_configure_opts += -opengl desktop
endif

Here is the xenial's build log and it shows OpenGL as Desktop version.

- Xenial build log: https://launchpadlibrarian.net/319422529/buildlog_ubuntu-xenial-arm64.qtbase-opensource-src_5.5.1+dfsg-16ubuntu7.5_BUILDING.txt.gz
  OpenGL / OpenVG:
    EGL .................. yes
    OpenGL ............... desktop

However, the zesty's build log shows OpenGL as ES2.

- Zesty build log: https://launchpadlibrarian.net/328680692/buildlog_ubuntu-zesty-arm64.qtbase-opensource-src_5.7.1+dfsg-2ubuntu4~1.17.04.1_BUILDING.txt.gz
  OpenGL / OpenVG:
    EGL .................. yes
    OpenGL ............... yes (OpenGL ES 2.0+)

[Chanho Park (chanho61.park)]

Gently ping about this issue :)

[Dmitry Shachnev (mitya57)]

Hi!

It looks like you are quoting wrong debian/rules. Mine (5.5.1+dfsg-16ubuntu7.5) have:

gles2_architectures := armel armhf

And arm64 was added to this list only in Yakkety and later versions. So not having OpenGL ES on arm64 is intentional in Xenial.

[Chanho Park (chanho61.park)]

Hi Dmitry,

Thanks for the information about version difference.
Is there no possibility to update the Xenial's qt5 build as yakkety because the Xenial is LTS version and I need the feature for the arm64.

[Dmitry Shachnev (mitya57)]

There is no possibility of updating qtbase-opensource-src, as that will break the whole Qt stack.

What I can do is adding arm64 builds to a separate package, qtbase-opensource-src-gles. Please try the package in this PPA: https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/2912/+packages

[Timo Jyrinki (timo-jyrinki)]

If you're advanced user and don't mind to use the ppa-purge tool from pure console mode in case something goes wrong, there's (nowadays abandoned but Qt should be functional) PPA at https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/stable-phone-overlay/ that contains Qt 5.6.2 for Ubuntu 16.04, including qtbase compiled with -opengl es2 for arm64.

You should be safer if you try the PPA out from a desktop environment that doesn't strictly depend on Qt 5 - while the Qt itself in that PPA should be as functional as before, some Stable Release Upgrade that has happened after April 2017 may have made eg KDE Plasma or LxQt incompatible with the PPA.