System freeze on a T490 laptop

Some time ago I tried to migrate my laptop to FreeBSD. I've managed to install 13.0 and everything seemed to be fine, but then I started having these complete system freezes. Since I was running X, I wasn't seeing anything on the console. I didn't had too much time to investigate (and learn!), so I had to abort the migration.

Today I tried to repeat the experiment with 13.1, on a Lenovo 13.1. The system freeze happened again while doing the installation:
  • I was configuring networking
  • iwm(4) scan didn't returned any wireless networks
  • plugged an ethernet cable to try to use the em(4) driver...
  • the system stopped responding, the laptop started to get hotter and the fans started
I had to hard-reboot, of course.

My question: I do I debug this? If I had to guess, it it's a network driver bug, either iwm(4) or em(4), but how can I get more info when this happens? I plan to try to re-install again without using the iwm(4) driver.

Another detail (probably irrelevant): I'm installing with encrypted root-on-zfs.
 
Back
Top