3.3.3.2 How Do I Position Functions at an Address I Nominate?

The easiest way to do this is to make the functions absolute, by using the address attribute (see 16.2.1 Function Attributes). This means that the address you specify is used in preference to the function’s symbol in generated code. Since you nominate the address, you have full control over where functions are positioned, but must also ensure that absolute functions do not overlap.