I once had a second-hand Sun Sparc system, and several Sun amd64 systems (discounted for startups), and I remember Sun having a fairly sophisticated serial-atta

I once had a second-hand Sun Sparc system, and several Sun amd64 systems (discounted for startups), and I remember Sun having a fairly sophisticated serial-attached firmware console. Though a fail-open default configuration that permitted trivially bypassing authentication seems more like something one would see w/ an x86 BIOS or bootloader. I wouldn't claim the serial-attached bootloaders on my x86 lab machines don't somehow permit bypassing login(1) authentication. But at least w/ EC2 and other hypervisors that element should be out of the equation.