3.6.2. DFU Boot

3.6.2.1. Overview

AM64x USB peripheral boot (also called device boot) mode receives second bootloader images from a USB host using Device Firmware Update (DFU) specification defined by USB-IF.

This section demonstrates how to use DFU to boot AM64x GPEVM to U-Boot prompt with a Linux Ubuntu PC.

3.6.2.2. Setup

Hardware

  • Refer to EVM Boot Mode Switches to set the AM64x GPEVM boot mode switches to USB Peripheral boot.
  • Connect the AM64x GPEVM usb port to the Linux PC USB host port.
  • Remove headers on Jumper J23 on AM64x GPEVM to let the USB port work in device mode.

Software

  • The commonly used DFU tool on Linux host is dfu-util. Use the following command to install it on the Ubuntu PC:
$ sudo apt update && sudo apt install dfu-util

  • The Processor SDK prebuilt U-Boot images are used in this demo. The image files are located under <SDK_DIR>/board-support/prebuilt-images/ folder on the Linux host.

    • tiboot3.bin
    • tispl.bin
    • u-boot-am64xx-evm.img

3.6.2.3. DFU Boot Procedure

Command Summary

The following commands are used on the Linux host to transfer the U-Boot images.

$ sudo dfu-util -R -a bootloader -D tiboot3.bin
$ sudo dfu-util -R -a tispl.bin -D tispl.bin
$ sudo dfu-util -R -a u-boot.img -D u-boot-am64xx-evm.img

Transfer tiboot3.bin

Power on the AM64x GPEVM. Run the following command on the Linux host to ensure the ROM DFU device is enumerated.

$ sudo dfu-util -l
...
Found DFU: [0451:6165] ver=0200, devnum=7, cfg=1, intf=0, path="3-4.1.3", alt=1, name="SocId", serial="01.00.00.00"
Found DFU: [0451:6165] ver=0200, devnum=7, cfg=1, intf=0, path="3-4.1.3", alt=0, name="bootloader", serial="01.00.00.00"

Note name=”bootloader” in the message above, it means the EVM is waiting to receive tiboot3.bin. Run the following command on the Linux host to transfer tiboot3.bin:

$ sudo dfu-util -R -a bootloader -D tiboot3.bin

After the host shows the transfer is complete, the EVM UART console should show the following messages.

U-Boot SPL 2021.01-g53e79d0e89 (Jul 23 2021 - 21:08:20 +0000)
SYSFW ABI: 3.1 (firmware rev 0x0015 '21.5.0--v2021.05 (Terrific Llam')
SPL initial stack usage: 13392 bytes
Trying to boot from DFU

Transfer tispl.bin

Now run command dfu-util -l command on the Linux host again, it should show the following messages:

$ sudo dfu-util -l
...
Found DFU: [0451:6165] ver=0224, devnum=12, cfg=1, intf=0, path="3-4.1.3", alt=1, name="u-boot.img", serial="UNKNOWN"
Found DFU: [0451:6165] ver=0224, devnum=12, cfg=1, intf=0, path="3-4.1.3", alt=0, name="tispl.bin", serial="UNKNOWN"

Note name=”tispl.bin” in the message above, it tells the EVM is waiting to receive the U-Boot image tispl.bin. Now run the following command on the Linux host to transfer tispl.bin:

$ sudo dfu-util -R -a tispl.bin -D tispl.bin

After the host shows the transfer is complete, the EVM UART console should show the following messages.

####################################DOWNLOAD ... OK
Ctrl+C to exit ...
init_env from device 10 not supported!
Starting ATF on ARM64 core...

NOTICE:  BL31: v2.5(release):08.00.00.002-dirty
NOTICE:  BL31: Built : 21:09:01, Jul 20 2021

U-Boot SPL 2021.01-g53e79d0e89 (Jul 23 2021 - 21:08:19 +0000)
SYSFW ABI: 3.1 (firmware rev 0x0015 '21.5.0--v2021.05 (Terrific Llam')
Trying to boot from DFU

Transfer u-boot-am64xx-evm.img

Now run the following command on the Linux host to transfer u-boot.img:

$ sudo dfu-util -R -a u-boot.img -D u-boot-am64xx-evm.img

After the host shows the transfer is complete, the EVM UART console should show the following messages.

####DOWNLOAD ... OK
Ctrl+C to exit ...


U-Boot 2021.01-g53e79d0e89 (Jul 23 2021 - 21:08:19 +0000)

SoC:   AM64X SR1.0
Model: Texas Instruments AM642 EVM
Board: AM64-GPEVM rev E2
DRAM:  2 GiB
MMC:   mmc@fa10000: 0, mmc@fa00000: 1
In:    serial@2800000
Out:   serial@2800000
Err:   serial@2800000
Net:   eth0: ethernet@8000000
Hit any key to stop autoboot:  0

Now press any key on the EVM UART console will enter the EVM U-Boot prompt.