Re: Upcoming Qt switch to OpenGL ES on arm64
On Friday 23 November 2018 06:37:28 Dmitry Shachnev wrote:
> On Thu, Nov 22, 2018 at 06:01:14PM -0500, Gene Heskett wrote:
> > I think a better question would be: Does it improve, or disable,
> > decent video support for the dozens of arm64 cards in the r-pi
> > format, such as the arm64 based $44 rock64? [...]
>
> As far as I know Raspberry Pi 3 and similar devices work fine with
> OpenGL ES.
>
> E.g. Raspbian does not override our choice to build qtbase with OpenGL
> ES on armhf.
>
> --
> Dmitry Shachnev
Not on my machine, which because its running real machinery, has
something like a realtime kernel substituted into a jessie lite install
so the kernel and matching lib are pinned to keep apt from installing
non-realtime stuff. And recovering from a kernel update that apt wants
to install involves building a whole new sd card since its impossible to
make an image with dd that fits on the next sd card, no 2 are the exact
same size but doesn't because of the pinning, so your OpenGL ES update
is not done.
So first I need a new realtime kernel and library that will live with
your OpenGL ES. I have downloaded and built several linux-rt kernels on
this pi as I've attached a 60 GB SSD, but there is no installer I have
been able to find, and no one wants to tell me where to find one that
works with the weird partitioning scheme the pi's boot loader uses.
These so-called realtime kernels I've tried all suffer from an un-init'd
var someplace that causes keyboard and mouse events to be thrown away
until its been rebooted several times and finally hits a sweet spot and
works until the next power bump.
The kernel it runs best is a bit old, uname reports:
Linux picnc 4.4.4-rt9-v7+ #7 SMP PREEMPT RT Mon Mar 7 14:53:11 UTC 2016
armv7l GNU/Linux
But newer ones I've tried, do the throwaway events thing much worse, the
keyup event being lost the machine continues its jog until you hit the
power switch or pound on the keyboard until a keyup event gets thru.
On the SSD, I have linux-rpi-4.14.y-rt, and linux-rt-devel-4.16.18-rt9
ready for a test install, but nothing to do the actual install to the sd
card. The makefile doesn't know how to do it on the pi-3b. Since Stephan
R's mandate about file locks being done wrong there has been quite a
flurry of patches but no on is claiming a stable build yet. But I am
marking the msgs with git links anyway.
I see the rt folks have been releasing new stuff (I'm lurking on their
list) at a high rate recently, so I should pull and build one again.
And I've quite a pile of 32GB sd cards just waiting for a good rt kernel
for the pi's. But it seems u-boot demands stuff at fixed addresses in
the boot media. Meaning the install is usually by writing a new sd card.
Not Funny thing is, I have seen apt install a new kernel on the rock64
running armbian stretch, since its also a u-boot booter, proof that it
can actually be done on a live system, arm64 in that case.
--
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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