On power up the DEL key or the F2 key will get you into the BIOS. Alternatively F12 or F7 will bring up the BBS POPUP.
With my unit the opening screen identified the BIOS as BAT-I2 Release 02/04/2016. In the BIOS main screen it is also labelled as IQBW7-2.
A quick check of the VXL website showed downloads for the manuals but not for any firmware. Firmware downloads required you to fill in a fairly comprehensive form...
The F12 brings up a boot option screen which shows a list of whatever bootable items it finds. In this example I had a Sandisk USB pen drive plugged in to one of the front USB ports and a wiped internal flash drive:
Please select boot device:PO: 8GB SATA Flash Drive SanDisk Enter Setup↑ and ↓ to move selection ENTER to select the boot device ESC to boot using defaults
The BIOS is an American Megatrends BIOS with the heading 'Aptio Setup Utility' and consists of seven screens: