4.3.7.7 How Do I Make a Function Wrapper For an Assembly Module?

The C compiler expects all C visible names to start with a leading underscore. In order to export a function to C code from assembly code, it must be globally visible. Of course, there should also be an external prototype in C so that the compiler can properly see it.

foo.s:

       .text
       .global _foo
 _foo: retlw #0,w0

main.c:

 extern int foo(void);

For details on using C code with an assembly module, see the following section of this user’s guide:

17.1 Mixing Assembly Language and C Variables and Functions