[U-Boot] u-boot fall-back application

Hi, Is it possible to have a standalone application started without the user intervention (auto-started at power-on)? I need to create a fall-back application which will boot a safe kernel if booting a user flashed kernel fails. We will store 2 kernel images in flash and if one of them is corrupted we need u-boot to try booting the second one. How can I test if a kernel image is corrupted?

Regards, Florin