How to load some code from specific location from EEprom?

Hi,

I want to add an option to my espruino toolset that will support a fallback app code mechanism when uploading code by both wifi and uart interfaces.

I know there is Wifi Remote Console code available already, so there is only a fallback mechanism left to implement.

When I upload a new code, my bootloader will boot from newly uploaded code. If some kind of heartbeat is not found for a while, it will reboot and load the last known good code.

So the question is, how can I save/load a code to/from from a specific location of EEprom?