I have had this occur on both FreeBSD and OpenBSD, with slightly different Intel Atom processors.
Switching TTY is generally problem-free. Once Xorg is running on a TTY, switching away from that TTY to a console TTY causes no problems. However, switching from console TTY to an Xorg TTY causes the entire system to crash, with a crazy glitch-looking mix of colours on the screen, sometimes pink, sometimes blue, etc. Note this doesn't happen when starting Xorg, either. So the only way to switch from console TTY back to Xorg TTY without crashing, is to run: rcctl stop xenodm rcctl -f start xenodm When I have checked in the past there have been no indicating logs in Xorg, probably because of the crash. There is no response to keyboard/mouse input once it has crashed, so nothing more can be done other than a hard reset. I can only think using a serial port might offer a route for diagnostics. Any suggestions? I could live with bug, but it is time-wasting nuisance.
