Linuxcnc won't boot on raspberry pi 3b+

After installing the LinuxCNC 2.8.0 Raspberry Pi OS based on Debian 10 Buster iso on my raspberry pi 3b+, I cannot get past the rainbow boot screen. Does anyone know how to fix this? The standard iso from www.raspberrypi.org/software/operating-systems/ works fine.

That image is for RPI4, not for 3B.
Do not know if that will work or not, and can not recall where a RPI3 image can be found.

tommylight wrote: That image is for RPI4, not for 3B.
Do not know if that will work or not, and can not recall where a RPI3 image can be found.

an old link ...

wiki.linuxcnc.org/cgi-bin/wiki.pl?RPi3BPreemptRT

elovalvo wrote:

tommylight wrote: That image is for RPI4, not for 3B.
Do not know if that will work or not, and can not recall where a RPI3 image can be found.

an old link ...

wiki.linuxcnc.org/cgi-bin/wiki.pl?RPi3BPreemptRT

Sorry, was not aware of that.

Hi

I tried to install on Rpi-400 and on Rpi-4b 4Gb. The system froze on both.
This applies to version 2.8 as well as version 2.81.

Jaro

jaro_p wrote: I tried to install on Rpi-400 and on Rpi-4b 4Gb. The system froze on both.
This applies to version 2.8 as well as version 2.81.

That's disappointing, and I don't know how to fix it, as it works on all the Pi's that I have tried it on.

I have run out of enthusiasm for buying Pi's just to test my SD card image on. (Bought a 400 and a Pi4 _just_ for testing, I have no other use for them)

There is a 5.10 RT kernel out there, with .debs. But I am not sure if they work:

github.com/kdoren/linux/releases/tag/5.10.16-rt30

In theory the instructions here:
linuxcnc.org/docs/2.8/html/getting-start...lling_on_raspbian_10
Except for using a different kernel .deb should work.

I just experienced a problem with these same symptoms on my 3b+. I followed those instructions, but rebooting after installing the rt kernel froze on the rainbow screen, with the green led blinking in a pattern of seven. Searching that indicated that kernel.img wasn't found. Mounting the boot media on my laptop showed there was a kernel7l.img but not kernel.img. Symlinking didn't work, but cp'ing kernel7l.img to kernel.img restored normal booting on my pi.