Custom Mint-19.2 with Linuxcnc

Hello BeagleBrainz,

First off, Fantastic work!! This really helps the community!

I installed your RTAI + Mate version here: forum.linuxcnc.org/9-installing-linuxcnc...cnc?start=140#159389 and think I may have found a solution that corrects the following 2 issues you have listed.

If screen doesn't show login prompt move the mouse in circles for a few seconds

Login screen issue is an entropy issue that shows up with fast fast machines and/or SSDs

My system is a J1900 processor with 8GB of DDR3 memory and SSD disk. It is very fast to boot and fit the symptoms perfectly. After s little research I found Haveged details here: community.linuxmint.com/software/view/haveged which maintains the entropy pool when there is not enough mouse/keyboard use to fill the pool. Thats why the mouse needs to be moved around, to fill the pool.

This seems to have fixed the issue for me. Hope it can help someone else too!

-Adam

Cheers Adam

Yeah I saw that a few weeks ago, never got around to researching it a great deal. If you reckon it works next update I'll add it to the list of installed packages.

Thanks for the feedback, much appreciated
Rob

Hi Rob,

I have tested the fix of installing "haveged" in a VM instance and it did in-fact fix the entropy issue.

Original boot was 300 seconds before "crng init done" showed up in dmesg. After installing haveged, the dmesg shows "crng init done" occuring around 6.5 seconds and the system instantly comes up with the login.

I think this corrects the issue.

-Adam

Hi Rob,

I was finishing up my configuration when I found that this image (19.2 Mate RTAI) crashes hard when launching LinuxCNC with a Mesa 6i25. I don't even get a kernel panic, it just locks up solid. I have tested this on the installed system and the live image with the same results. Nothing is even logged to kern.log so I have no idea why its dying.

Im probably going to move back to the preempt image to get running but preempt latency was 76us while RTAI ws 11uS.

-Adam

adamj12b wrote: Im probably going to move back to the preempt image to get running but preempt latency was 76us while RTAI ws 11uS.

If you are running a 6i25 then latency is almost irrelevant, 76µs is perfectly acceptable.

That would be one for the kernel guys.
Unfortunately I can’t do much testing with RTAI as I don’t have the hardware to work with it .