As outlined in Boot Devices and Firmware Overview, the AMD 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 AMD starter kit Linux provides a utility for doing these updates entirely on-target. The steps for using the AMD SOM A/B update tool are documented in the Wiki page at: Boot FW Update Process.