Raspberry Pi 4 Tutorial - fatal error

This is very helpful! Thanks!

I, too, am experiencing a CPU 0 error on boot.

I've gotten my RPi4 flashed, loaded, configured, and communicating with my Mesa 7I76E board. I'm totally new to Linux CNC and Mesa boards, so I'm working through getting that figured out.

I don't have a frame of reference to understand if the CPU 0 error is fatal. Everything seems to still be working. Should I be concerned? Do I also need to figure out how the buildbot works?

Edited to add:
I had ~ 75000 ns jitter on my Servo thread and ~90000ns jitter on my Base thread with 18 glxgears open.

Can it be removed from the kernel config?

Thanks for the prompt responses. I connected my monitor and rebooted the Pi to verify that it was the same error message I was getting. Naturally, I suddenly can't reproduce it. Oh well. I did change my config settings to run headless (/boot/config.ext and raspi-config resolution), so maybe that had something to do with the error message.

I've got two more questions while I'm here:
1. I've installed the OS several times now (3-4) because I was troubleshooting the most efficient way to go from nothing to a totally-functional, headless RPi4. I was writing a tutorial. This last time I did so, I find that if I spend too long in the PnCConfig application (say, 5 minutes) it will kick me out. It appears as though the application is faulting with no warning. I had to fly through the configuration to get it to work. My next troubleshooting step is going to be to just install the OS again and give it another shot -- I don't think I had this issue on my first install. Any ideas?

Which brings me to my second question:

2. I'm running my RPi4 on a MicroSD card. Some online research suggests that the device will perform much better with a good external SSD; however, that same research concludes that the USB port shares traffic in some way with the Ethernet port, whereas the MicroSD card does not. It sounds like a tradeoff... better overall performance of the Pi, or better Ethernet performance. I'm using it with a Mesa 7I76E -- could you folks share your thoughts?

Hello David
I've run into the very same issue today.
Raspberry Pi 4B boots into the graphical UI but mouse and keyboard will not work.
I am using the latest image from here: www.linuxcnc.org/iso/linuxcnc-2.8.0-pi4.zip.

Many thanks for any advice, Gero

Update: it seems to be related only to 8GB. I tried it with a 4GB RPI and it works well. I think its a kernel issue in this built.

Same here, gui but no usb mouse and keyboard