Are there any standard boot protocols for Edge and IoT devices?

After reading about the ServerReady program and SBSA standards as mentioned in other posts, it made me wonder, are there any similar sets of standards for IoT and Edge devices?  I don't really want to fight with U-Boot, learn custom boot sequences for many different types of boards and SoC's, or worry about OS updates knocking devices offline.  I want to just focus on my workload, and ensuring data is flowing to and from my devices.