I see. But manually assigning absolute addresses to individual variables is an extremely cumbersome way to do this!
It will be a maintenance nightmare!

It is the Linker's job to assign addresses to program "objects" (code & data) - you can either tell it an address range to exclude from data use, or a range to allow for data use.
See the Linker Manual.


Better late than never!
Remember, though, that you need to understand the whole tool chain - including Linker and Compiler...