I’m suspicious that this doesn’t magically “reboot” by causing BIOS to POST and run the boot sequence. I suspect that it actually enters BIOS code with a horribly corrupt state, which causes a triple fault and resets the machine.
On a modern system, it resets a whole lot of things, including state that firmware expects to have initialized and various lock registers that can’t be unlocked without a reset.
You can’t just run your system firmware kexec-style and expect it to work.
That's fair. The last time I looked into the space of what happens on a reset on x86, hardware roots of trust were significantly less important to the point of not really being on my radar.
