The IGEL M310C has a standard PC Phoenix Award BIOS - on power-up/reset hit the DEL key after you hear the beep in order get into the BIOS setup screens. NB A cheap anonymous USB wired keyboard did nothing at this point, however a Labtec one worked fine.
In the dmesg output I find: IGEL Technology GmbH M310C/VX855 , BIOS 6.00 PG 07/20/2011
The BIOS boot options are:
If you have a bootable USB pen drive inserted then it will appear in the separate Hard Disk Boot Priority entry.