How to Get to the BIOS in OS X
Basic Input/Output System (BIOS) is an interface found on PC computers. Mac OS X has its own version of BIOS called OpenFirmware or Extensible Firmware Interface. Just like BIOS on a PC, OpenFirmware can be used to communicate instructions to your operating system. For example, you can eject a CD, view a directory, change your boot order, and set up password protection.
Restart your computer.
Hold down the "Command," "Option," "F" and "O" keys simultaneously while your computer is booting up.
Type your username and password if prompted. You will see the following text on your computer screen: "ok 0>"This indicates that you have entered OpenFirmware (BIOS).
Tips & Warnings
- If you want to set up a password to prevent unauthorized users from entering OpenFirmware, type "password" (without the quotation marks) and press "Enter." You will be prompted to choose a password. Type the password you want to use and press "Enter." Then, type "setenv security -mode full" (without the quotation marks). Press "Enter," type "reset-all" (without the quotation marks) and press "Enter."