Boot Firmware A/B Update

As outlined in the Boot Devices and Firmware Overview section, the Xilinx starter kit and SOM provide two copies of the boot firmware in the QSPI device. This mechanism has a robust update infrastructure through a ping-pong methodology, where the last known good boot image is always kept available in the platform. The Xilinx starter kit Linux provides a utility for doing these updates entirely on-target. The steps for using the Xilinx SOM A/B update tool are:

1. Place the new BOOT.BIN in the Linux file system.
2. Execute the A/B update process through these steps:
   1. Go to the directory where you copied the BOOT.BIN in step 1.
   2. Type sudo xmutil bootfw_update -i <location of new BOOT.BIN>.
   3. The tool returns the image (A or B) that is updated, and is marked for boot on the next boot.
   4. You can verify the updated status of the boot firmware using the sudo xmutil bootfw_status utility.
3. Power cycle the device or press the board reset button.
4. After restart, Linux must fully boot with the new boot firmware to verify functionality. This is completed by executing a sudo xmutil bootfw_update -v command to validate the successful boot against the new firmware.
   Note: This step must be completed on the platform restart immediately following the update. If not done in this order, on the next restart the platform will fall back to the previous boot partition.
5. After reboot, verify the updated status of the boot firmware using the sudo xmutil bootfw_status utility to confirm the expected image revision, selection, and bootable state are correct.