@phnt >That's how your computer and many of it's other subsystems start up/bootstrap [1]
Only laptops have EC's and the boot process of the thinkpad is;
EC detects power button press->global reset signal->CPU init into real mode->coreboot init and switches to 32-bit mode->RAMinit and remaining hardware init->GRUB loaded

Desktops and servers generally use a SuperIO

>You are welcome to disassemble the firmware and with a custom lowlevel OS find out what the separate flags do.
The proprietary license on the peripheral software attempts to forbid reverse engineering, because there's certainly not malware in there.

>I seriously doubt Intel VT-X and AMD-V run without microcode.
Both VT-x and AMD-V with KVM work just fine running GNU/Hurd for me without proprietary software.

Software emulation works too, but it's slower.

>if they do, it's broken, because the microcode that is on the CPU die itself is weeks/months old even when the manufacturing starts.
If the manufacturer is half competent, like AMD was during the Opetorn 62XX days, the original microcode is plenty stable, as it's not like there's anything special about a slightly faster CPU.