Determining U-Boot Version
From embeddedTS Manuals
The U-Boot build date can be viewed as the first line of USB console output when the unit is powered on. For example:
U-Boot 2016.03-00408-gd450758c91 (Oct 10 2019 - 11:59:08 -0700) CPU: Freescale i.MX6UL rev1.2 at 396 MHz ...