Designing C code from an algorithm in Simulink that also calls hardware-specific functions shouldn't be difficult, right?
For example, the algorithm could call a (hardware) function "void switch_Light(uint8)".
Since neither Simulink nor the PC compiler ("Visual Studio" or similar) knows this function, you could define an auxiliary function (for simulation purposes) and get the correct hardware function call (for the external hardware compiler) substituted with a "Code Replacement Library".
Apparently, this option does not exist? The examples included in help demonstrate other scenarios.
Does anyone have experience with this and can sketch a simple, working example of the above function call?