The linutop 5 can be bought here, but when looking in their "quick user
guide" found here, I find this: Linutop can boot on other PCs
BOOTING on an external USB Key
It should boot automatically on USB key if not:
1 insert the USB key
2 Power On and enter
BIOS settings
(Del or F2 key...)
3 Go to Boot menu and Select Hard Disk Drives
4 As a First Boot Drive Select USB: Generic Flash D
isk
5 Press F10 to save
That doesn't sound like a free BIOS to me. If you could specify what kind of
device you are looking for, maybe I could make some more recommendations.
Anyway, good luck!