Gene, on 2019-08-30:
> I found the u-sd card with a debian-arm buster net-install on it. And I
> generally like what I see. Then I noticed there was a newer kernel
> marked preempt-rt. What the hell, give it a shot, and installed it along
> with the mesa-utils pkgs.
>
> rebooted, runs fine. Ran glxgears full screen, getting about 9 fps.
> Nowhere near the 27 fps I get out of a raspian buster install, but is
> still around 7.5 fps faster than jessie or stretch gave me, a quite
> worthwhile improvement.
>
> So, over the next week I'll setup a build environment on a plugged in ssd
> and see if I can build an arm64, deb format version of linuxcnc. That
> would be a good sized feather in my hat!
Good day Gene,
It sounds good; let us know how things evolve. :)
If the end result is not satisfactory, I vaguely recalled my
school days, which are actually pretty nearby from today, and my
course on Real-Time Operating Systems. Various kernels and
systems have been mentioned, notably:
- RTAI (you mentioned that in another thread),
- QNX (I don't suppose you are willing to spend hundreds of
thousands on that one, but it was pretty neat in the past),
- Xenomai (this was the main RT engine of the course).
I see Xenomai was part of Debian at some point, but the package
is currently orphaned:
https://packages.debian.org/search?searchon=sourcenames&keywords=xenomai
Upstream, the project seems still running:
https://www.xenomai.org/
I guess you might want to start here:
https://gitlab.denx.de/Xenomai/xenomai/wikis/Start_Here
Browsing a bit on their wiki, they advertise being compatible
with your Pi 3B (it's in the liste of "Supported Evaluation
Boards"):
https://gitlab.denx.de/Xenomai/xenomai/wikis/Supported_Hardware#arm
Of course, this advice comes from a guy who thinks CPU cycles
should be reserved for scientific computations, not doing kernel
mode stuff juggling with tasks. So, take this with a gentle
grain of salt. ;)
Have you had the occasion to consider Xenomai in the past ?
Do you think it could be compatible with your CNC toolset ?
> Cheers, Gene Heskett
Happy hacking and kind regards,
--
Étienne Mollier <etienne.mollier@mailoo.org>
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