Asus Maximus II Formula - Manual (Page 46)

2-20 Chapter 2: Hardware information
2. BIOS flash setting (6-pin BIOS_FLASHBACK)
Two sets of BIOS Flash ROM (BIOS 1 and BIOS 2) are present on this
motherboard. This jumper allows you to select either BIOS as the one to boot,
or back up or restore BIOS content from one ROM to the other.
Moving the jumper cap to pins 1-2 (default) allows you to enter BIOS MENU
to select which BIOS to boot.
Moving the jumper cap to pins 3-4 enables the system to boot from BIOS 1.
Moving the jumper cap to pins 5-6 enables the system to boot from BIOS 2.
BIOS LED
When the BIOS backup starts, the system will enter the soft-off state and the
BIOS LED will blink to indicate that the backup is proceeding.
Refer to 3.7.3 BIOS Boot Priority for further information.
Refer to 3.8.3 BIOS Flashback for further information.