Intel S2600IP Service Guide - Page 164

BIOS Setup Utilities Note: USB devices can be "hotplugged" during POST, and will be detected and "beeped". They will be enumerated and displayed on the USB Configuration Setup screen. However, they may not be enumerated as bootable devices, depending on when in POST they were hotplugged. If they were recognized before the enumeration of bootable devices, they will appear as Boot Devices if appropriate. If they were recognized after Boot Device enumeration, they will not appear as a bootable device for the Boot Options screen, the Boot Manager screen, or the F6 Boot Menu. There are two main types of boot order control, Legacy Boot and EFI Optimized boot. These are mutually exclusive - when EFI Optimized Boot is enabled, Legacy Boot (the default) is disabled. Within Legacy Boot operation, there are two further methods of ordering boot devices, Dynamic Boot Order and Static Boot Order. The default for Boot Order control is Legacy Boot, with Dynamic Boot Order. If all types of bootable devices are installed in the system, then the default Boot Order is as follows:  CD/DVD-ROM  Floppy Disk Drive  Hard Disk Drive  PXE Network Device  BEV (Boot Entry Vector) Device  EFI Shell and EFI Boot paths In this default Boot Order, a USB device may appear in any of several Device Classes, due to the flexibility of USB connections and USB emulation of various types of devices. Note: A USB Key (USB Flash Drive) can be formatted to emulate either a Floppy Drive or a Hard Drive and will appear in that Boot Device Class. However, although it can be formatted as a CDROM Drive, it will not be detected as such. It will be treated as a Hard Disk and will appear in the list of available Hard Drives. 152 Intel® Server System R2000IP Service Guide