Asus ESC8000 G4 Series User Manual page 146

Boot Override
These items displays the available devices. The device items that appears on the screen
depends on the number of devices installed in the system. Select an item to start booting
from the selected device.
Launch EFI Shell from filesystem device
This item allows you to attempt to launch the EFI Shell application (shellx64.efi) from one of
the available filesystem devices.
Chapter 5: BIOS Setup
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