How do I have two applications that share code

Note: this is for an MSP430 based project

I want to have two projects in my solution, one for a base, and one for an "application".

I would like to set up each as Executable, so that each project can be configured to build a TXT file output.That way I can have separate TXT files for the base, and the application. This way in-field updates will only load the application portion, while the base (which has the loader code) will be untouched.

My current plan is to have two Executable projects, each with their own section placement file placing code in different regions. Each will have its own CRT startup code, and when the base jumps to the app, it would call the APP's CRT which initializes its RAM and runs as if it owns the system. The app would also be able to jump to the base using similar logic.

The application will likely use functions in the base code (such as UART comms). I do not want to duplicate this code. Can you cross link executable projects like this? 

Also, can the debugger track this, or is it going to lose context when the jump is made to the other code?

Has anyone done something like this?