- The user can now access the boot menu by pressing the ESC key. Previously, the boot menu could only be accessed by pressing the F12 key. However, one some platforms, F12 can be unavailable. For example, systems running the OS X operating system can intercept certain function keys, including F12. With this update, the user can use either ESC or F12 to access the boot menu. Therefore, seabios avoids these potential problems associated with F12.