started setting up support for C code in the kernel

kernel/src/main.rs

@@ -28,6 +28,11 @@ static _START_MARKER: RequestsStartMarker = RequestsStartMarker::new();
 #[link_section = ".requests_end_marker"]
 static _END_MARKER: RequestsEndMarker = RequestsEndMarker::new();
 
+
+extern "C" {
+    pub fn add(x: i32, y: i32) -> i32;
+}
+
 #[no_mangle]
 unsafe extern "C" fn kmain() -> ! {
     // All limine requests must also be referenced in a called function, otherwise they may be
@@ -35,6 +40,8 @@ unsafe extern "C" fn kmain() -> ! {
     assert!(BASE_REVISION.is_supported());
 
     lib_example::add_nums(1, 2);
+    add(1, 2);
+
 
     if let Some(framebuffer_response) = FRAMEBUFFER_REQUEST.get_response() {
         if let Some(framebuffer) = framebuffer_response.framebuffers().next() {