u-boot/doc/README.dfutftp

1 # SPDX-License-Identifier: GPL-2.0+
7 Device Firmware Upgrade (DFU) - extension to use TFTP
11 ----
16 eMMC, SD, partitions, RAM, etc) via USB.
22 --------
25 upgrading firmware (e.g. kernel, u-boot, rootfs, etc.)
29 possible to overcome the major problem of USB based DFU -
39 for USB based DFU (CONFIG_DFU_*) and DFU TFTP update
42 The "dfu" command has been extended to support transfer via TFTP - one
47 As of this writing (SHA1:8d77576371381ade83de475bb639949b44941e8c v2015.10-rc2)
49 contemporary u-boot tree.
53 ---------------------
62 -----------------------------
65    *  select desired eth device - 'ethact' variable ["ethact=cpsw"]
74 It is possible to use USB interface to emulate ETH connection by setting
75 "ethact=usb_ether". In this way one can have very fast DFU transfer via USB.
77 For 33MiB test image the transfer rate was 1MiB/s for ETH over USB and 200KiB/s
78 for pure DFU USB transfer.
81    *  set "updatefile" - the file name to be downloaded via TFTP (stored on
85     "preboot" env variable. Otherwise use this command from u-boot prompt.
88    * "dfu_alt_info" - information about available DFU entities
89    * "dfu_bufsiz"   - variable to set buffer size [in bytes] - when it is not
95 -----------------------------
104 			description = "U-Boot binary";
109 		u-boot.bin@1 {
110 			description = "U-Boot binary";
112 where "u-boot.bin" is the DFU entity name to be stored.
117 -----
119 * Extend dfu-util command to support TFTP based transfers