Multi-Application Programming for ARM

The example shows how you can split a project into two parts that can be developed independent from each other.

The application implements a classic Blinky example, but the part that performs the LED blinky is in a separate project that can be translated independent from the Main Program.

The Main.uv2 project contains for convenience both parts Main Part and AddOn and is configured in two targets:

• Main Program which allows to generate the Main Program and is configured for program debugging.
• Addon Function which allows to create the program part that contains the add on function.

The Addon.uv2 project contains only the Addon and shows how to configure a project that hides the Main Program.

Project Generation

The Main Part exports the symbols to AddOn via the --symdefs directive of the RealView Linker. In this case the file main.obj is created which is a standard text file. It should be noted that main.obj is a two way file - only the symbols that are contained in this file are updated which allows you to hide symbols form the Main Part. If you delete main.obj all symbols of the Main Part are exported to main.obj.

In the Addon project, the linker reads main.obj as object file to get the symbol values of the Main Program. This means that Addon can use all these symbols as if they were part of the application.

Memory Setup

For the Main Part the standard uVision method is used to configure the linker. The memory definitions under Project - Options - Target exclude the memory used by the add-on extension.

For the AddOn the linker scatter file .\Addon.SCT is used that specifies the memory regions available for the add-on extension.

Debugging and Flash Programming

The target Main Program is configured for Debugging and Flash Programming of the complete application. The Addon is loaded in the Initialization File Sim.ini and Flash.ini using the LOAD debugger command with the option INCREMENTAL. This gives access to all symbols of the Main Part and the Addon during debugging and downloads the complete application to Flash ROM.