The IGEL M320C has a BIOS that identifies itself as InsydeH20.
In the Linux dmesg output we find: IGEL Technology GmbH M320C/VX900, BIOS M320C V:3.3.131-0508201 05/08/2013.
Hit the DEL key on power-up in order get into the BIOS setup screens.
There's not a lot to set in the Boot options. You can enable/disable: Quick Boot, Quiet Boot and PXE Boot to LAN.
Under Legacy you can play about with the boot order between the local flash SATA drive and what ever is plugged into the USB ports.