USB/DFU
Overview
AM62x USB peripheral boot (also called device boot) mode receives a second bootloader image from a USB host using the Device Firmware Update (DFU) specification defined by USB-DFU.
This section demonstrates how to use DFU to boot phyCORE-AM62x to a U-Boot prompt using a Linux Ubuntu PC.
Requirements
Hardware
Ubuntu 22.04 LTS, 64-bit Host Machine
If using a virtual machine, VMWare Workstation, VMWare Player, and VirtualBox are all viable solutions.
USB-C to USB-A cable
Software
Prepare the following U-Boot images by building the BSP (Build the BSP) or downloading the pre-built (Pre-Built Binaries) image files. These images will be used for downloading to and booting on the phyCORE-AM62x via DFU:
* tiboot3.bin-usbdfu * tispl.bin * u-boot.img
Note
tiboot3.bin-usbdfu is built along side tiboot3.bin and is used for USB-DFU boot on the phyCORE-AM62x.
Install & Configure Snagboot
Install python3, pip, and swig:
host:~$ sudo apt update && sudo apt install python3 python3-pip python3-venv swig
Now we can create and source our python virtual environment in the same folder that we have our U-Boot images.
host:~$ python3 -m venv myenv host:~$ source myenv/bin/activate
Install snagboot in our venv using pip
host:~$ pip install snagboot
Export the PHYTEC template
host:~$ snagrecover -t am62x-phyboard-lyra > am62x-phyboard-lyra.yaml
We can cat the template to verify it is exported correctly:
host:~$ cat am62x-phyboard-lyra.yaml tiboot3: path: tiboot3.bin-usbdfu tispl: path: tispl.bin u-boot: path: u-boot.img
Note
If the template shows tiboot3.bin-perif, you will need to update it to tiboot3.bin-usbdfu as shown above.
Add udev rules to allow snagrecover to access our USB devices:
host:~$ snagrecover --udev > 50-snagboot.rules host:~$ sudo cp 50-snagboot.rules /etc/udev/rules.d/ host:~$ sudo udevadm control --reload-rules host:~$ sudo udevadm trigger
Note
If we run ls our folder should include at least the following files to begin recovery:
host:~$ ls
am62x-phyboard-lyra.yaml
myenv
tiboot3.bin-usbdfu
tispl.bin
u-boot.img
Booting from USB/DFU
Here are the basic steps for booting from USB/DFU on the phyCORE-AM62x development kit. The steps for establishing a serial communication are outlined in the Quickstart.
Note
- Two terminals should be open on your host Linux machine.
One for running commands via USB-C
One for Serial communication to see the SOMs boot status.
Boot Switch Settings
Plug a USB-C cable from the phyCORE-AM62x development kit into your Ubuntu machine.
Adjust boot switch settings on the phyCORE-AM62x development kit.
Power on the phyCORE-AM62x development kit.
You should see the kit appear on your Ubuntu machine via the USB-C. To verify this, run the following:
host:~$ lsusb | grep 0451:6165 Bus 005 Device 060: ID 0451:6165 Texas Instruments, Inc. AM62x DFU
We can now begin our recovery by running snagrecover on our Ubuntu machine in our USB-C terminal.
host:~$ snagrecover -s am625 -f am62x-phyboard-lyra.yaml Starting recovery of am625 board Installing firmware tiboot3 Searching for partition id... Downloading file... Could not read status after end of manifest phase Done Done installing firmware tiboot3 Installing firmware u-boot Searching for partition id... Downloading file... Done Done installing firmware u-boot Installing firmware tispl Searching for partition id... Downloading file... Done Sending detach command... Done installing firmware tispl Done recovering am625 board
We should see the following response on our serial terminal:
Target (Serial)U-Boot SPL 2024.04-ti-ge20920b7fc3d (Aug 20 2024 - 12:39:00 +0000) SYSFW ABI: 4.0 (firmware rev 0x000a '10.0.8--v10.00.08 (Fiery Fox)') SPL initial stack usage: 13392 bytes Trying to boot from DFU dwc3-am62 dwc3-usb@f900000: unable to get ti,syscon-phy-pll-refclk regmap #################################################DOWNLOAD ... OK Ctrl+C to exit ... ############################################DOWNLOAD ... OK Ctrl+C to exit ... Authentication passed Authentication passed Authentication passed Loading Environment from nowhere... OK init_env from device 10 not supported! Authentication passed Authentication passed Starting ATF on ARM64 core... NOTICE: BL31: v2.10.0(release):v2.10.0-367-g00f1ec6b87-dirty NOTICE: BL31: Built : 16:09:05, Feb 9 2024 U-Boot SPL 2024.04-ti-ge20920b7fc3d (Aug 20 2024 - 12:39:00 +0000) SYSFW ABI: 4.0 (firmware rev 0x000a '10.0.8--v10.00.08 (Fiery Fox)') SPL initial stack usage: 1904 bytes Trying to boot from DFU dwc3-am62 dwc3-usb@f900000: unable to get ti,syscon-phy-pll-refclk regmap ####DOWNLOAD ... OK Ctrl+C to exit ... Authentication passed Authentication passed U-Boot 2024.04-ti-ge20920b7fc3d (Aug 20 2024 - 12:39:00 +0000) SoC: AM62X SR1.0 HS-FS Model: PHYTEC phyBOARD-Lyra AM625 DRAM: 2 GiB Core: 70 devices, 28 uclasses, devicetree: separate MMC: mmc@fa10000: 0, mmc@fa00000: 1 Loading Environment from nowhere... OK In: serial@2800000 Out: serial@2800000 Err: serial@2800000 Net: eth0: ethernet@8000000port@1 Hit any key to stop autoboot: 0 =>
We should see U-Boot start up and attempt to boot from the SD-Card. We can stop in U-Boot by pressing any key at this point.
Boot Switch Settings
S7 should be ON to overide default boot settings.