spiutil DEVICE r LENGTH
Read LENGTH bytes from the specified devfs node. Output will be on the console in hexdump format.
spiutil DEVICE w BYTES ...
Write BYTES to the SPI bus represented by the specified devfs node.
spiutil DEVICE x BYTES ...
Perform a full-duplex SPI exchange on the SPI bus represented by the specified devfs node. Transmitted data as w option above, output as r option.