USB/DFU
Overview
AM62Ax 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-AM62Ax 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-AM62Ax via DFU:
* tiboot3.bin-perif * tispl.bin * u-boot.img
Note
tiboot3.bin-perif is built along side tiboot3.bin and is used for periferal boots on the phyCORE-AM62Ax.
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-perif tispl: path: tispl.bin u-boot: path: u-boot.img
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-perif
tispl.bin
u-boot.img
Booting from USB/DFU
Here are the basic steps for booting from USB/DFU on the phyCORE-AM62Ax 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-AM62Ax development kit into your Ubuntu machine.
Adjust boot switch settings on the phyCORE-AM62Ax development kit.
Power on the phyCORE-AM62Ax 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 2023.04-ti-g59f060e92e96 (Mar 14 2024 - 22:53:08 +0000) SYSFW ABI: 3.1 (firmware rev 0x0009 '9.2.1--v09.02.01 (Kool Koala)') am62a_init: board_init_f done SPL initial stack usage: 17088 bytes am62a_init: spl_boot_device: devstat = 0x453 bootmedia = 0xa bootindex = 1 Trying to boot from DFU #################################################DOWNLOAD ... OK Ctrl+C to exit ... ###############################################DOWNLOAD ... OK Ctrl+C to exit ... Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Loading Environment from nowhere... OK am62a_init: spl_boot_device: devstat = 0x453 bootmedia = 0xa bootindex = 1 am62a_init: spl_boot_device: devstat = 0x453 bootmedia = 0xa bootindex = 1 init_env from device 10 not supported! 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 2023.04-ti-g59f060e92e96 (Mar 14 2024 - 22:53:08 +0000) SYSFW ABI: 3.1 (firmware rev 0x0009 '9.2.1--v09.02.01 (Kool Koala)') am62a_init: board_init_f done am62a_init: spl_boot_device: devstat = 0x453 bootmedia = 0xa bootindex = 1 Trying to boot from DFU ####DOWNLOAD ... OK Ctrl+C to exit ... Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted Warning: Detected image signing certificate on GP device. Skipping certificate to prevent boot failure. This will fail if the image was also encrypted U-Boot 2023.04-ti-g59f060e92e96 (Mar 14 2024 - 22:53:08 +0000) SoC: AM62AX SR1.0 GP Model: PHYTEC phyBOARD-Lyra AM62A7 DRAM: 2 GiB Core: 65 devices, 30 uclasses, devicetree: separate MMC: mmc@fa10000: 0, mmc@fa00000: 1 Loading Environment from nowhere... OK In: serial@2800000 Out: serial@2800000 Err: serial@2800000 phytec_eeprom_data_init: EEPROM data is all zero. Erased? phytec_eeprom_data_setup: EEPROM data init failed Net: Could not get PHY for ethernet@8000000port@1: addr 1 am65_cpsw_nuss_port ethernet@8000000port@1: phy_connect() failed No ethernet found. 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.