# 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)
  - MTD (all MTD device: NAND, SPI-NOR, SPI-NAND,...)
  - virtual

  These DFU backends are also used by
  - the dfutftp (see README.dfutftp)
  - the thordown command (cmd/thordown.c and gadget/f_thor.c)

  The "virtual" backend is a generic DFU backend to support a board specific
  target (for example OTP), only based on the weak functions:
  - dfu_write_medium_virt
  - dfu_get_medium_size_virt
  - dfu_read_medium_virt

Configuration Options:
  CONFIG_DFU
  CONFIG_DFU_OVER_USB
  CONFIG_DFU_MMC
  CONFIG_DFU_MTD
  CONFIG_DFU_NAND
  CONFIG_DFU_RAM
  CONFIG_DFU_SF
  CONFIG_DFU_SF_PART
  CONFIG_DFU_VIRTUAL
  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>"

                   when only several device are used, the format is:
                   - <interface> <dev>'='alternate list (';' separated)
                   - each interface is separated by '&'
                dfu_alt_info=\
                   "<interface1> <dev1>=<alt1>;....;<altN>&"\
                   "<interface2> <dev2>=<altN+1>;....;<altM>&"\
                   ...\
                   "<interfaceI> <devI>=<altY+1>;....;<altZ>&"

  "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
      <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

  "mtd" (all MTD device: NAND, SPI-NOR, SPI-NAND,...)
    cmd: dfu 0 mtd <dev>
      with <dev> the mtd identifier as defined in mtd command
      (nand0, nor0, spi-nand0,...)
    each element in "dfu_alt_info" =
      <name> raw <offset> <size>  raw access to mtd 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

  "virt"
    cmd: dfu 0 virt <dev>
    each element in "dfu_alt_info" =
      <name>

  <interface> and <dev> are absent:
    the dfu command to use multiple devices
    cmd: dfu 0 list
    cmd: dfu 0
   "dfu_alt_info" variable provides the list of <interface> <dev> with
   alternate list separated by '&' with the same format for each <alt>
       mmc <dev>=<alt1>;....;<altN>
       nand <dev>=<alt1>;....;<altN>
       ram <dev>=<alt1>;....;<altN>
       sf <dev>=<alt1>;....;<altN>
       mtd <dev>=<alt1>;....;<altN>
       virt <dev>=<alt1>;....;<altN>

Callbacks:
  The weak callback functions can be implemented to manage specific behavior
  - dfu_initiated_callback  : called when the DFU transaction is started,
                              used to initiase the device
  - dfu_flush_callback      : called at the end of the DFU write after DFU
                              manifestation, used to manage the device when
                              DFU transaction is closed

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 1: 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


  Example 2: firmware located in NOR (sf) and NAND, with:
  - alternate 1 (alt=1) for SPL partition (NOR GPT partition 1)
  - alternate 2 (alt=2) for U-Boot partition (NOR GPT partition 2)
  - alternate 3 (alt=3) for U-Boot-env partition (NOR GPT partition 3)
  - alternate 4 (alt=4) for UBI partition (NAND GPT partition 1)

  U-Boot> env set dfu_alt_info \
  "sf 0:0:10000000:0=spl part 0 1;u-boot part 0 2; \
  u-boot-env part 0 3&nand 0=UBI partubi 0,1"

  U-Boot> dfu 0 list

  DFU alt settings list:
  dev: SF alt: 0 name: spl layout: RAW_ADDR
  dev: SF alt: 1 name: ssbl layout: RAW_ADDR
  dev: SF alt: 2 name: u-boot-env layout: RAW_ADDR
  dev: NAND alt: 3 name: UBI layout: RAW_ADDR

  U-Boot> dfu 0

  $> dfu-util -l
  Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
     intf=0, alt=3, name="UBI", serial="002700333338511934383330"
  Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
     intf=0, alt=2, name="u-boot-env", serial="002700333338511934383330"
  Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
     intf=0, alt=1, name="u-boot", serial="002700333338511934383330"
  Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
     intf=0, alt=0, name="spl", serial="002700333338511934383330"

  Same example with MTD backend

   U-Boot> env set dfu_alt_info \
      "mtd nor0=spl part 1;u-boot part 2;u-boot-env part 3&"\
      "mtd nand0=UBI partubi 1"

  U-Boot> dfu 0 list
  using id 'nor0,0'
  using id 'nor0,1'
  using id 'nor0,2'
  using id 'nand0,0'
  DFU alt settings list:
  dev: MTD alt: 0 name: spl layout: RAW_ADDR
  dev: MTD alt: 1 name: u-boot layout: RAW_ADDR
  dev: MTD alt: 2 name: u-boot-env layout: RAW_ADDR
  dev: MTD alt: 3 name: UBI layout: RAW_ADDR

  Example 3: firmware located in SD Card (mmc) and virtual partition on
             OTP and PMIC not volatile memory
  - alternate 1 (alt=1) for scard
  - alternate 2 (alt=2) for OTP (virtual)
  - alternate 3 (alt=3) for PMIC NVM (virtual)

   U-Boot> env set dfu_alt_info \
      "mmc 0=sdcard raw 0 0x100000&"\
      "virt 0=otp" \
      "virt 1=pmic"

   U-Boot> dfu 0 list
   DFU alt settings list:
   dev: eMMC alt: 0 name: sdcard layout: RAW_ADDR
   dev: VIRT alt: 1 name: otp layout: RAW_ADDR
   dev: VIRT alt: 2 name: pmic layout: RAW_ADDR