Add and test an invalid opcode handler function

src/interrupts/mod.rs

@@ -23,6 +23,7 @@ lazy_static! {
         let mut idt = idt::Idt::new();
 
         idt.set_handler(0, handler!(divide_by_zero_handler));
+        idt.set_handler(6, handler!(invalid_opcode_handler));
 
         idt
     };
@@ -53,3 +54,13 @@ extern "C" fn divide_by_zero_handler(stack_frame: *const ExceptionStackFrame)
     }
     loop {}
 }
+
+extern "C" fn invalid_opcode_handler(stack_frame: *const ExceptionStackFrame)
+    -> !
+{
+    unsafe {
+        print_error(format_args!("EXCEPTION: INVALID OPCODE at {:#x}\n{:#?}",
+            (*stack_frame).instruction_pointer, *stack_frame));
+    }
+    loop {}
+}

src/lib.rs

@@ -52,12 +52,8 @@ pub extern "C" fn rust_main(multiboot_information_address: usize) {
     // initialize our IDT
     interrupts::init();
 
-    fn divide_by_zero() {
-        unsafe { asm!("mov dx, 0; div dx" ::: "ax", "dx" : "volatile", "intel") }
-    }
-
-    // provoke a divide by zero fault inside println
-    println!("{:?}", divide_by_zero());
+    // provoke a invalid opcode exception
+    unsafe { asm!("ud2") };
 
     println!("It did not crash!");
     loop {}