This program boots an i.MX or Vybrid system using a copy of U-Boot
transferred to the system over an OTG or UART connection.  It can be
used to "unbrick" a system which has a corrupted or missing copy of
U-Boot in nonvolatile media such as nand flash or eeprom.  i.MX systems
use the OTG port, Vybrid systems use the UART port.

To use this, connect the OTG port of your i.MX board to a USB host
port on your computer, power on the board, then run imx_usb <filename>
where filename is the board-specific u-boot.imx file to boot with.