mac geekery

Hi, i’m trying to secure my box (ma mini intel). I RTFM and i was finally searching for my firmware utility to set up a password for my harware..
Is it possible it not to be intalled on my machine? i’m running Mac OSX 10.5.8…
Any idea about where can i find it? I searched in google and apple support but it only speaks about firmware updates.

thanks in advance