ok, if you talking about "logical security" it will work. but if i lock up the box, why not do that thru O.S.? you cant get access to hard disk anyway... see may point? if you harden enough the box, you dont have concern about o.s. security. but if i can break the hardware (i can hammer your stone walls and enter, and fix the hole before i leave) i can do what i want - including access the bios chip -
I don't see what good that does for you. The box is locked up in a room (room security is another matter), but obviously one you can't get to. The BIOS is still out of your reach, and the OS -and- hardware is still secure because of protocol rewriting and limitation coding.

Now you've blown and ruined your own point by pulling the "nothing is secure" argument. Of course you could hammer down the walls, but that just isn't going to happen because of practicality reasons. Are you seriously suggesting that you would just pound through the concret walls into the server? With a harddrive that is still 4000+ encrypted? No security is ever 100% safe, but you can make it hard enough to not be worth the trouble.

So... back at square one. How would you try use the BIOS without the features of inputting to crack a system in another room?