CONFIG_USBD_STORAGE
  Enable the generic mass storage function driver. This function is
  used emulating a Linux block driver.

CONFIG_USBD_STORAGE_VENDORID
  Optionally specify the mass storage USB Device Vendor ID. The top
  level Vendor ID will be used if this is not specified.

CONFIG_USBD_STORAGE_PRODUCTID
  Optionally specify the mass storage USB Device Product ID. The top
  level Vendor ID will be used if this is not specified.

CONFIG_USBD_STORAGE_OUT_ENDPOINT
  Specify the preferred OUT (received data) endpoint number. This is a
  number from 0-15 and must be allowed by the bus interface device.

  Some devices such as the SA-1110 or L7205/L7210 may override this
  value with a fixed value.

CONFIG_USBD_STORAGE_IN_ENDPOINT
  Specify the preferred IN (transmit data) endpoint number. This is a
  number from 0-15 and must be allowed by the bus interface device.

  Some devices such as the SA-1110 or L7205/L7210 may override this
  value with a fixed value.

CONFIG_USBD_STORAGE_INT_ENDPOINT
  Specify the preferred INT (interrupt) endpoint number. This is a
  number from 0-15 and must be allowed by the bus interface device.

  Some devices such as the L7205/L7210 may override this value with a
  fixed value. Others such as the SA-1110 do not allow an interrupt
  value.

CONFIG_USBD_STORAGE_OUT_PKTSIZE
  Specify the maximum packet size for the OUT endpoint. This allowable
  values are normally 16, 32 and 64. 

  Some devices such as the Linkup L7205/L7210 may override this value
  with a lower maximum value (such as 32).

CONFIG_USBD_STORAGE_IN_PKTSIZE
  Specify the maximum packet size for the IN endpoint. This allowable
  values are normally 16, 32 and 64. 

  Some devices such as the Linkup L7205/L7210 may override this value
  with a lower maximum value (such as 32).

CONFIG_USBD_STORAGE_INT_PKTSIZE
  Specify the maximum packet size for the INT endpoint. This allowable
  values are normally 8 and 16. Some bus interface devices may not
  support all values.

CONFIG_USBD_STORAGE_DEF_DEVICE_NAME
  Specify the default block device name to used on mass storage.