I think this is a custom board (especially given the lithium battery and USB charging), but they copied the design from an industrial using the M6117. I've seen a ton of devices that use the same pair of an M6117 and a CHIPS F65535 VGA chip. You can still find stocks of both on places like Utsource. I do wish they had just gone with the more modern Vortex86 instead, perhaps someone will design an open hardware equivalent to this device that uses one of them instead.