add interrupt tests (3h21m)

src/interrupts.rs

@@ -17,4 +17,10 @@ extern "x86-interrupt" fn breakpoint_handler(
     stack_frame: InterruptStackFrame)
 {
     println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
+}
+
+#[test_case]
+fn test_breakpoint_exception() {
+    // invoke a breakpoint exception
+    x86_64::instructions::interrupts::int3();
 }

src/lib.rs

@@ -50,6 +50,7 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
 #[cfg(test)]
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
+    init();
     test_main();
     loop {}
 }