RPi 5 with 6.12 PREEMPT_RT = Using POSIX non-realtime

Perhaps a unified test platform for the "sysgen" aspect would help.

Tom

@gene_weber There is one Linux kernel at the heart of all of them maintained by the Linux kernel team. But there are with many different numbered versions and with a whole galaxy of different patches that get applied by distribution maintainers, as well as civilians like me and rodw.

If you just want a working PREEMPT_RT kernel with LinuxCNC, install rodw's image.

TomAlborough wrote:

Perhaps a unified test platform for the "sysgen" aspect would help.

Tom
 

Tom would you like to elaborate on what you mean ?

Yes I can @cornholio.

It takes a certain set of steps to go from sources to executables ("sysgen" it has been called). If those steps end up in a script that anyone can run, starting with perhaps a fresh Ubuntu install (or pick any distribution), then the sysgen script would take it from there to completion (a running LinuxCNC that any of its users could work with).

"make" was supposed to handle this job but has not, I believe, given all the patching and version number matching that has been required to get running systems.

Am I close to what the current situation is?

Tom

That's the function of Rod's fork of the rpi image builder. To be honest it is not required to used by a run of the mill Linuxcnc user. In Nov\Dec of 2023 it was working and working very well, as far as I know it was just Rod working on it and occasionally he'd bounce a few off me and I'd run the script as well, make a few changes here and there. At the end of the day it was Rod's baby, and did the job required. Apart from Rod there have been only contributions from 3 other people, with Rod doing the bulk of the work.
As for unified, I don't know if that applies, as it would seem this is the only project addressing this task. Whilst some users have started with RPi OS as a base that because they wanted to do things their way for whatever reason, and was never an option that rpi-img-builder was going to address.
There is a similar utility for the PC platform, that rarely gets a mention on the forum, for building PC images. For those that want an easy and hassle free entry it does the job. For those that want to use a different distro, ie not debian, they usually do their own thing.
I guess how tight Linuxcnc & Debian are is unusual for Linux, one would admit that Linuxcnc is not your usual run of the mill app. Actually it is more a complete suite that integrates with hardware that most other projects don't. Another good point with Debian is that they really try to stick with the OSS ethos, which would be the reason there are many distros that Debian based.
That is not to say that Linuxcnc will not run on other distros. I've used Mint, Slackware and Linux from Scratch project to build systems for Linuxcnc. It can be done but can take a fair bit of time and in reality I can't say if its better or worse.
As for kernel versions, well that's a personal choice, whether the most recent kernel or one that is a year or so old as long as it works, as most do, it's probably academic.

In conclusion I would suggest that there is a unified image creation utility, it would seem the kernel is the driving force. I don't many would care what kernel version is used as long as it works, it's only really when someone is aware of a new release that they start thinking about it and suggest can we use kernel x.x.x, which would seem reasonable with a user coming from the windows world with the focus on updates.

Hello @cornholio:

I do understand some of the things you are saying. 

I'm not a LinuxCNC'er so please bear with me.

A start might be to enumerate types of users as I see them:

Gold users just want to get something done (say make parts for a space station). Their CNC machines are already supported by LinuxCNC. They would appreciate a working version of LinuxCNC. Once they get it they probably will not change it over time unless they need to support new devices or new features.

The key here is that installing and getting LinuxCNC running should be as easy as it is to get Raspberry Pi 5 or Ubuntu up in the first place. (I'm not sure if my experience getting RPi5 up is similar to getting RPi4 up but more on that later).

If a newcomer can not get a version going enough to run say a "Maslow" machine (please Google "maslow cnc kit") then work still needs to be done.

Silver users/developers know and contribute to the LinuxCNC GitHub repo. The users have absolute control of the repo and the CNC, sysgen and testing features merged into it.

Bronze users/developers know and contribute to the Linux GitHub repo. The users have absolute control of the repo and the OS, sysgen and testing features merged into it.

The question comes: How to manage the need for support between Gold, Silver and Bronze users. I'm not sure of a solution here but I believe some solution will arise.

Tests should exist that (all) developers can run and get understandable results from. The only issue should be coverage at a given point in time. Hopefully the more tests you develop and manage the better off everyone should be.

I realize some of the above exists. It just needs to be pulled together.

An observation about configuration files: I think they may have gotten a bit out of hand.

I believe plain text files are easier for users to work with than XML but, a coherent "system build, installation and configuration" facility may be easier to develop and maintain if the configuration is rationally represented by some data handling facility (not a DBMS).

Please let me know your thoughts up to this point.

Many thanks,
Tom

I think the biggest issue is your trying to jump in without actually using Linuxcnc, if you did, you have used the configuration utilities. Once one has a working config, one does not need to doing anything with it, unless of course you add features. Everything need not be in one huge config, it can be split. In fact you would have also investigated the various supplied simualtion configs.

The core devs will raise issues on github, casual ones may raise an issue on github or discuss it on the forum, other users will raise an issue on the forum, and the devs that hang out on the forum will usually look into it and take it from there.

The build system does have tests, I believe the buildbot system does compilation and run tests. Again this is a dev thing.

Once again the image building utilities are generally only run and new images released when major changes come about, say when there is a "point release".

I truly think if your looking to make some wholesale changes the better option would be to go to the Linuxcnc homepage, find the links for the mailing lists and sign up and put your ideas across there.

As for getting Linuxcnc up & running. Images exist for amd64 platform & the RPi5 & Rpi4 platforms. RPi platforms are simple the image is dd'd to a sd card and you boot up.
The amd64 platform is just as simple to run as a "live" you dd the image to a USB device and you boot to a live session to "have a play around" and do a "ballpark" latency test. Installation requires a reboot and the you run the installer, being the debian installer it is no different to installing debian.
32 bit images are still available, but generally not used much (as far as I am aware), so Linuxcnc can be run on older hardware.

There's probably thousands of users that have never used for the forum as it "just works for them" or they can get all the info required from the docs or internet searches.

I'm starting to think that your discussion is getting quite off topic, you seem more interested not so much as using Linuxcnc but a shake up in the general way support happens. I'm starting to get the feeling I did when the whole CoC thing was forced upon a lot of OSS projects. This is something I will not discuss as my views will by in violation of the CoC.

And quite honestly I think the mailing lists would be a better place for this, mind this is just my opinion.

Now if you require any advice regarding practical use or installation of Linuxcnc I'm quite happy to help, but I have no further interest in what seems to be your main point of interest.

Best Wishes

My RPi5 kit has come up. A book report:

The full kit name as listed in Amazon is:

  -- iUniker - Extreme Starter Kit for Raspberry Pi 5 - (8GB RAM - 128GB Storage Edition)
  
Definitely a learning experience (several delicate operations but that's probably good if you are needing to learn).

• A critical concern with all electronics not designed to handle it is electrostatic discharge (ESD). Shuffle across a rug and touch the bare board and your new RPi5 may never come up. The RPi5 specs make a nod toward ESD protection but one way to get by ESD, if you don't have a special "static discharge mat", is to lay down a very slightly damp cloth and work on it.
•  I only received a 64 GB SD card instead of a 128 GB SD Card.
•  I only received one video cable instead of 2.
•  Once installed, the fan connector needs to be inserted into a plug on the board. The plug seemed to elude me for quite a while but it's there. Be very sure of which way around the plug needs to be oriented.
• The 4 USB connectors are very, very difficult to insert into. I worried about the stress on the board. I opted for a hard-wired keyboard/mouse combo and had to use 2 USB connectors. It supports wireless keyboard/mouse combos if you have them in pairing mode at system boot time.

Finally, it came up, started, and took my breath away. Very cool.
Tom

Hello @cornholio,

You are right - I need to move on to LinuxCNC. I noticed a new CNC machine. It's called "Maslow". Google it as "Maslow CNC".

I want to use it for cutting out frame members for wooden boats.

Does LinuxCNC support it or does something need to be done?

Tom