Custom Mint-19.2 with Linuxcnc

The "spector V2 kernel" message is particular to the RTAI kernel, it will come up on both the Mate & XFCE iso's. This can be confirmed via running
Output should similar to this
Spectre V1 : Mitigation: usercopy/swapgs barriers and __user pointer sanitization
Spectre V2 : Spectre mitigation: kernel not compiled with retpoline; no mitigation available!

One thing I have noticed on my laptop is that with the RTAI mate install I have to press a key and wiggle the mouse before the login comes up. I checked the dmesg output and it looks like it may be related to entropy.

BeagleBrainz wrote:

The "spector V2 kernel" is particular to the RTAI kernel, it will come up on both the Mate & XFCE iso's.

One thing I have noticed on my laptop is that with the RTAI mate install I have to press a key before the login comes up. Not too sure what this issue is but I have a feeling it maybe related to the Nvidia GPU I have in the laptop. I can't see I've seen this issue on my desktop.

It never got tos see the login screen but I might have clicked the auto login when it was asking the the user name etc on install.

Never mind I tried. All the other iso's you produced have worked fine. Thanks for all the hard work you put in.

Here is a sample of my dmesg

You can see an almost 30 second gap between the first and second msgs, Once the screen went "black" as it does before the login screen usually comes up I counted up to 30 then wiggled the mouse and pressed shift. A second later the login screen appeared, note I don't use auto login.

I would expect to see similar messages on Clive's machine with the Mate install.

Here's an explanation I found on the net: devtalk.nvidia.com/default/topic/1057547...due-to-ratelimiting/
Not on a x86 platform, but related to linux kernel & realtime.

During startup that isn't really an error. Under load some real time options cannot meet the real time behavior and the message will occur. Logging itself limits how fast log messages can be generated. urandom in particular depends on certain "seeds" to the random data generation, and if that activity (such as mouse movement) does not exist, then the pseudo random data cannot be generated as fast as expected. Even after startup you might see similar logs.

The black screen at boot, ie suppression of kernel & init messages is set by the kernel switch "quiet".

To see kernel & init messages I remove the quiet & splash kernel switches in grub.

In the images I have removed the quiet & splash switches, hence you see the kernel messages & init messages prior to the login screen. This was to aid in seeing when the hang on Generating SSL Certificates when booting mostly in a Virtual machine.

Mint 19.3 XFCE RT_PREEMPT Available for testing


Mint 19.2 Mate RTAI here forum.linuxcnc.org/9-installing-linuxcnc...xcnc?start=10#157707
Mint 19.2 Mate RT_PREEMPT here forum.linuxcnc.org/9-installing-linuxcnc...uxcnc?start=0#157411
Mint 19.3 XFCE RTAI here forum.linuxcnc.org/9-installing-linuxcnc...xcnc?start=30#157796

• Linux Mint 19.3 XFCE with 4.16.12-rt5-kona-rt
• Linuxcnc v2.8 from sources Latest commit 084acf1
• Geany, gFTP & Midnight commander included
• Initramfs modified to work when booted from a vfat filesystem, ie supports Multiboot
• qtvcp screens & designer support included
• Mesaflash and hostmot2 firmware

Please use win32diskimager if using a windows machine to write image to disk.
In Linux dd is recommended.

Unlike other images I posted this has been created using a virgin install of Mint 19.2 on real hardware.
To apply updates to fresh install open a terminal and use the following, this should not upgrade the kernel.
ISO Image:
No longer available do not ask for access

MD5 Checksum:
No longer available do not ask for access

All issues and support should be directed to this thread.

Well this seemed to work perfect out of the box on my J1850 PC
I wanted to get to Version 2.9 and tried to do it in buildbot but could not get it to work so I ended up compiling from source cos by then I had deleted V 2.8. All up it took about 2 hours to copy the ISO to a memory stick and get it done.

I'm used to running from source as thats what I've always done. I will build a 2.9 deb file if I get a moment. Never bothered with that before.

Remember to install 3rd party drivers and enable auto logon.

The instructions on building from source are really good in the docs. I did the check build dependency thing. and just cut and pasted the output on to the command line after typing "sudo apt-get install ". There are a couple of spots in brackets with version numbers etc so it was just a matter of deleting them and also one that had 2 different libraries need the incorrect one deleted. apt-get will complain about the one it can't find. It worked perfect and compilation was a breeze.

The only problem I have is the Baytrail chipset overheats and the PC shuts down without notice every now and again. It needs power removed to restart. I think its due to some incompatibility with the BIOS and Linux so the OS does not reduce power consumption as it gets up near a critical temperature or something.. If anybody has a solution, it would be great if you could share it...

If Clive is watching, if you are still having problems with your BRIX J1900, maybe give this one a go.

Have you run an RT_PREEMPT kernel before with no issue on this PC and if you have what version was it ?

Seems to be a few issues, when googled, with Baytrail.

Have you seen this rod ?
askubuntu.com/questions/803640/system-fr...with-intel-bay-trail

I don't know what the affects of the intel_idle.max_cstate=1 on realtime.

BeagleBrainz wrote:

Have you run an RT_PREEMPT kernel before with no issue on this PC and if you have what version was it ?

Seems to be a few issues, when googled, with Baytrail.

Have you tried this rod.
sudo apt-get remove thermald

Yes this was a problem before on this PC and since my last post I found the linux issue report that runs to about 1000 posts over 4-5 years. and still no solution. There was a patch to the kernel that would be included in this version of Mint but it did not completely solve it.

I added a switch to the Grub command line as suggested in a few places but that did not fix it so I stopped the thermald service for a while and it was perfect so I've uninstalled thermald as you suggested. I think this must be the solution. If I fry the PC it does not really matter as I only paid $70 for it.

Its a shame actually as these little Industrial PC's are a really nice unit.