If you are memory mapping stuff like that you most likely already have your own linker script or something from the vendor of arch1 and you can, with not much pain, adapt the linker script for arch2 to use the same base addresses and magic numbers. I mean I haven't personally done it but worked on projects were we were doing that and the headers for both archs were almost the same.

If you don't have hardcoded addresses and are fully abstracted by a modern HAL and VM like on Linux then it's mostly a problem of the Linux distro or the OS vendor.