RPI4 Raspbian 64 bit & LinuxCNC

Hi Cornholio your image with 7 gears

 

5.15.65 with Linuxcnc 2.9pre

If you look closely one test had 3 cores isolated and the other has no cores isolated. That will make a huge difference.
As per my last post this has been addressed.
If you edit as root /boot/broadcom/cmdline.txt and add isolcpus=1,2,3 to the end of the line,reboot and test again then that will be a fair comparison.

New image
drive.google.com/file/d/1i4flcwKPysOzlks.../view?usp=drive_link

Note images have time in file in form of YYYY-MM-DD-HH-MM , so if you are browsing be sure to grab the latest one.

Donno only 2 cores are isolated so you wont get the same performance as your one with 3 cores isolated. But that can be fixed by editing /boot/broadcom/cmdline.txt to suit. Are you using GPIO to turn steppers, hence running a base & servo thread ?

Seems to work

 

Great work. Latency seems high. Have you compared isolcpus=2,3 with what you are using? Isolating 3 of 4 cores is a bit excessive as Linuxcnc only needs  2 threads for base and servo threads. (1 thread with ethernet hardware)

It seems my Pi is not running the images I build. I am working away in the background with the upstream repo but encountered a bug tonight. It won't really help people unless they build the kernel but we should be able to lock down the full process. to avoid possible data entry errors. just clone and run

Could be an idea but then that's an extra level of support, and then if someone wants to run on Mint there's some trickery involved to get it to install the tool chains. Then there's the Arch guys, the Fedora guys and those that run windows, does qemu run inside a virtual machine ?  Users have issues building the Linuxcnc packages.
I think it'll be better to just have one image, support will be easier. Well just my opinion.

cornholio wrote:

I think it'll be better to just have one image, support will be easier. Well just my opinion.

We are using the Raspberry Pi repositories. Debian it is! Thats what they give us! Thats what we use!

I thought you were talking about people building their own images. I have a feeling that some peoples only use of Linux is for Linuxcnc and that maybe the only exposure they have.
I'm running the image builder on Mint as I just couldn't be bothered installing Debian or Ubuntu on my main machine just to build images.

Sorry there. My intention is to get this accepted as the official rpi builder for linuxcnc to replace this old one github.com/LinuxCNC/raspberrypi-linux  I don't think its even 64 bit. But ideally, it will be fully configured, ready to go and just using the user configurable features so there is no hacking into any core scripts.

There has been so many images shared around but some are dated and the build process is never shared and its never been based on the official builder like this one.

I'm building another image for the x86 I have to get back to. Its been reviewed by one of the main developers so it needs a couple of things polished.

But what excites me is  C0nelius upstream has another more generic ARM image builder so I'm keen to gve it a go for my 6 core Odroid N2+ which is gathering dust.

Excuse me if I've got this all wrong... but isn't the goal to produce an img for a RPi that can update this one:

www.linuxcnc.org/iso/linuxcnc-2.8.1-pi4.zip

linked from here:  linuxcnc.org/docs/html/getting-started/getting-linuxcnc.html

100% agree that a documented method of building such a thing is most useful but for 99% of folk a simple install-it-on-my-RPi in the normal manner is what they need.

FWIW after a couple of hours testing , Cornholio's latest seems very close to achieving that aim.

The 'normal' Raspian stylee dd from the SDCard to a USB SSD doesn't result in a bootable USB device but sticking Cornholio's .img on a USB SSD does boot... but didn't auto-resize the root partition a parted and resize2fs sorted that (no not idea but it worked!).

Apart from that I'm struggling to find issues but I'll keep playing with it.