I do suppose this is possible and in fact might be a good idea.
But I would first do a "hello world" example in the "normally correct" way to learn how the make file and the linker script need to be constructed. This done, you can decide how to proceed to place the file on an external media instead of inside the distribution.
When doing my own application I in fact used a symlink for the "correct" directory under "Vendors" so that "physically" my files were outside of the distribution make tree, anyway.
In fact I would only slightly modify the "correct" makefile so that the executable after being linked is not included in (moved to ?, symlinked to ? I don't remember... ) the directory that is zipped to be the root file system that is included in or comes with the Kernel Image.
-Michael