Spload

From Sp305x wiki

Allows uploading code to SPMP305x RAM via USB cable. Download the source here[1]. Be sure to call it like "sudo spload yourcode.bin", also the code has to be in pure binary form, no ELF header etc (objcopy -O binary ...). You must hold down the "camera key" while connecting your device to the pc (unit must be turned off while plugging it in). In case you have a serial port assembled to your device you will see some text saying "Boot From USB ISP".