It means that all the code is running in privileged kernel mode instead of user mode. Kernel mode is usually reserved for the operating system and device drivers only. If code running in kernel mode has an unhandled exception or error, the entire system will crash. This creates the BSOD or “blue screen of death” on Windows.

User mode is less privileged and where all your typical applications run. If something crashes in user mode, it only crashes that process, not the whole system.

It’s a crazy thing that they did. Very impressive technically, but not really useful.