My Orange Pi Zero (rev 1.4) has a SPI flash module soldered to the underside. I can see the devices /dev/spidev0.0 and /dev/spidev1.0, and I can write to them and read from them (with dd), but the data I read from them is always just null bytes. Obviously then I can't create a filesystem on them.   Is it possible to create a small filesystem on the SPI flash to add files? If not, how is it possible to store data on the SPI flash?   I'm running Armbian 5.30 with kernel 3.4.113