doc: dfu: Add dfu documentation
Add documentation for dfu stack and "dfu" command.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/doc/README.dfu b/doc/README.dfu
new file mode 100644
index 0000000..f5344e2
--- /dev/null
+++ b/doc/README.dfu
@@ -0,0 +1,144 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+Device Firmware Upgrade (DFU)
+
+Overview:
+
+ The Device Firmware Upgrade (DFU) allows to download and upload firmware
+ to/from U-Boot connected over USB.
+
+ U-boot follows the Universal Serial Bus Device Class Specification for
+ Device Firmware Upgrade Version 1.1 the USB forum (DFU v1.1 in www.usb.org).
+
+ U-Boot implements this DFU capability (CONFIG_DFU) with the command dfu
+ (cmd/dfu.c / CONFIG_CMD_DFU) based on:
+ - the DFU stack (common/dfu.c and common/spl/spl_dfu.c), based on the
+ USB DFU download gadget (drivers/usb/gadget/f_dfu.c)
+ - The access to mediums is done in DFU backends (driver/dfu)
+
+ Today the supported DFU backends are:
+ - MMC (RAW or FAT / EXT2 / EXT3 / EXT4 file system)
+ - NAND
+ - RAM
+ - SF (serial flash)
+
+ These DFU backends are also used by
+ - the dfutftp (see README.dfutftp)
+ - the thordown command (cmd/thordown.c and gadget/f_thor.c)
+
+Configuration Options:
+ CONFIG_DFU
+ CONFIG_DFU_OVER_USB
+ CONFIG_DFU_MMC
+ CONFIG_DFU_NAND
+ CONFIG_DFU_RAM
+ CONFIG_DFU_SF
+ CONFIG_CMD_DFU
+
+Environment variables:
+ the dfu command use 3 environments variables:
+ "dfu_alt_info" : the DFU setting for the USB download gadget with a comma
+ separated string of information on each alternate:
+ dfu_alt_info="<alt1>;<alt2>;....;<altN>"
+
+ "dfu_bufsiz" : size of the DFU buffer, when absent, use
+ CONFIG_SYS_DFU_DATA_BUF_SIZE (8MiB by default)
+
+ "dfu_hash_algo" : name of the hash algorithm to use
+
+Commands:
+ dfu <USB_controller> <interface> <dev> list
+ list the alternate device defined in "dfu_alt_info"
+
+ dfu <USB_controller> <interface> <dev>
+ start the dfu stack on the USB instance with the selected medium
+ backend and use the "dfu_alt_info" variable to configure the
+ alternate setting and link each one with the medium
+ The dfu command continue until receive a ^C in console or
+ a DFU detach transaction from HOST.
+
+ The possible values of <interface> are :
+ (with <USB controller> = 0 in the dfu command example)
+
+ "mmc" (for eMMC and SD card)
+ cmd: dfu 0 mmc <dev>
+ each element in "dfu_alt_info" =
+ <name> raw <offset> <size> raw access to mmc device
+ <name> part <dev> <part_id> raw acces to partition
+ <name> fat <dev> <part_id> file in FAT partition
+ <name> ext4 <dev> <part_id> file in EXT4 partition
+
+ with <partid> is the GPT or DOS partition index
+
+ "nand" (raw slc nand device)
+ cmd: dfu 0 nand <dev>
+ each element in "dfu_alt_info" =
+ <name> raw <offset> <size> raw access to mmc device
+ <name> part <dev> <part_id> raw acces to partition
+ <name> partubi <dev> <part_id> raw acces to ubi partition
+
+ with <partid> is the MTD partition index
+
+ "ram"
+ cmd: dfu 0 ram <dev>
+ (<dev> is not used for RAM target)
+ each element in "dfu_alt_info" =
+ <name> ram <offset> <size> raw access to ram
+
+ "sf" (serial flash : NOR)
+ cmd: dfu 0 sf <dev>
+ each element in "dfu_alt_info" =
+ <name> ram <offset> <size> raw access to sf device
+
+Host tools:
+ When U-Boot runs the dfu stack, the DFU host tools can be used
+ to send/receive firmwares on each configurated alternate.
+
+ For example dfu-util is a host side implementation of the DFU 1.1
+ specifications(http://dfu-util.sourceforge.net/) which works with U-Boot.
+
+Usage:
+ Example for firmware located in eMMC or SD card, with:
+ - alternate 1 (alt=1) for SPL partition (GPT partition 1)
+ - alternate 2 (alt=2) for U-Boot partition (GPT partition 2)
+
+ The U-Boot configuration is:
+
+ U-Boot> env set dfu_alt_info "spl part 0 1;u-boot part 0 2"
+
+ U-Boot> dfu 0 mmc 0 list
+ DFU alt settings list:
+ dev: eMMC alt: 0 name: spl layout: RAW_ADDR
+ dev: eMMC alt: 1 name: u-boot layout: RAW_ADDR
+
+ Boot> dfu 0 mmc 0
+
+ On the Host side:
+
+ list the available alternate setting:
+
+ $> dfu-util -l
+ dfu-util 0.9
+
+ Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
+ Copyright 2010-2016 Tormod Volden and Stefan Schmidt
+ This program is Free Software and has ABSOLUTELY NO WARRANTY
+ Please report bugs to http://sourceforge.net/p/dfu-util/tickets/
+
+ Found DFU: [0483:5720] ver=0200, devnum=45, cfg=1, intf=0, path="3-1.3.1", \
+ alt=1, name="u-boot", serial="003A00203438510D36383238"
+ Found DFU: [0483:5720] ver=0200, devnum=45, cfg=1, intf=0, path="3-1.3.1", \
+ alt=0, name="spl", serial="003A00203438510D36383238"
+
+ To download to U-Boot, use -D option
+
+ $> dfu-util -a 0 -D u-boot-spl.bin
+ $> dfu-util -a 1 -D u-boot.bin
+
+ To upload from U-Boot, use -U option
+
+ $> dfu-util -a 0 -U u-boot-spl.bin
+ $> dfu-util -a 1 -U u-boot.bin
+
+ To request a DFU detach and reset the USB connection:
+ $> dfu-util -a 0 -e -R