1. user@Host-002:~/u-boot$ sunxi-fel -v uboot u-boot-sunxi-with-spl.bin
  2. Stack pointers: sp_irq=0x00002000, sp=0x00005E08
  3. MMU is not enabled by BROM
  4. => Executing the SPL... done.
  5. usb_bulk_send() ERROR -7: Operation timed out