RPI4 Raspbian 64 bit & LinuxCNC

Here is the boot ready image. Install using rpi-imager or Balena Etcher (which I use)
drive.google.com/drive/folders/1Bv4ceKAa...4PQGjKfQ?usp=sharing
If there is more than one file look at the timestamps in the file name and grab the latest one.

User: cnc
password cnc:
after boot, run: sudo menu-config to set locale and timezone etc.

As configured you don't need a password to run sudo. If you don't like the thought of this, type Notes on the environment:
1. Forked from the offiical Raspberry Pi installer
2. Uses the Raspberry Bookworm Kernel 6.1.46 to match the latest PREEMPT_RT patch
3. XFCE desktop installed
4. isolcpus and other settings included for latency
5. Includes the device tree overlays from the official upstream sources
6 Linuxcnc built from Source. Refer the timestamp on the .img file for date aand time.

Repository here if you wish to build it (Follow steps in instructions.txt)
github.com/rodw-au/rpi-img-builder-lcnc/tree/linuxcnc
Lightly tested by Cornholio and myself

If additional optimisations are required, please let me know.

Hey rod if you run xz -vT0 image_name you can reduce the download to about 2GB or so

Hello Rodw, good job, I have been following this thread for a few days, I've even read your conversations on Github, very good support by the way from Cornholio, yesterday I built a debian bookworm image with rt core and I installed linuxcnc from the repository ( apt-get ....), then when I launched latency-histogram it gave me a warning: """"Note: Using Posix non-realtime""""", I thought it might be a configuration problem on my part. build the kernel, a few moments ago I looked to see if there were new updates on the topic in the forum and I see that you provided an image, I tried it with hope but the terminal gives the same warning, any ideas on this, greetings

Hey, I did test that "first" build from 01 Sep, it was booting well with RPI4b 4G.How is the SPI with this latest one? Cornholio,. you did some activities with that one?
I am having also 7C81 to be driven here,..

I haven't had a chance to run Rods image yet, I did you through the build process and built an image.
You need to make sure that the config.txt file has the line that enables spi uncommented. Otherwise you wont have spi. But I can confirm that with the kernel from the build process spi is fine. (as I use the same one for my private image)

I've had some issues. The last ones I've built are not booting. I Was going to go back to basics

@rbobey, can you report what uname -v and uname -4 report?
I will try and upload the kernel as a deb file

@mkei 
As per Cornholio, just enable spi in the /boot/broadcom/config.txt I think thats the right location. Umm you break things if you try to overcloick it there too......

PS Cornelius upstream is not  Cornholio here.