+- USB Device Firmware Update (DFU) class support:
+ CONFIG_DFU_FUNCTION
+ This enables the USB portion of the DFU USB class
+
+ CONFIG_CMD_DFU
+ This enables the command "dfu" which is used to have
+ U-Boot create a DFU class device via USB. This command
+ requires that the "dfu_alt_info" environment variable be
+ set and define the alt settings to expose to the host.
+
+ CONFIG_DFU_MMC
+ This enables support for exposing (e)MMC devices via DFU.
+
+ CONFIG_DFU_NAND
+ This enables support for exposing NAND devices via DFU.
+
+ CONFIG_SYS_DFU_MAX_FILE_SIZE
+ When updating files rather than the raw storage device,
+ we use a static buffer to copy the file into and then write
+ the buffer once we've been given the whole file. Define
+ this to the maximum filesize (in bytes) for the buffer.
+ Default is 4 MiB if undefined.
+