[RealityVoid]

In embedded you can usually modify every step from boot to main. They are just pieces of code you can interact with and make them do whatever you want and initialize stuff in whatever order you want, providing you know what you do.

Deviating with a war story now, I once modified some startup code so it self-detected its boot location and initialized the ram data according to this location shift. It was fun, but debugging code you relocated is a pain because you need to somehow relocate the symbols as well.

[2RTZZSro]

What was the project for where you wrote code that self-detected its boot location?

[RealityVoid]

Well, a bootloader and the self-detection was useful for the bootloader self-update. The update bootloader would be copied in a different section and on reset would start and copy itself over the original bootloader section.

I also wanted to maintain full functionality even at shifted location in case the self-copy process somehow failed. Never did fail, at least to my knowledge.