Add abort & update panic handler

src/main.rs

@@ -96,12 +96,24 @@ extern "C" fn start() -> ! {
     }
 }
 
-#[panic_handler]
-fn on_panic(info: &PanicInfo) -> ! {
-    // print panic info and hang
-    println!("{}", info);
+#[no_mangle]
+extern "C" fn eh_personality() {}
 
-    loop {}
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    // print panic info and abort
+    println!("{}", info);
+    abort();
+}
+
+#[no_mangle]
+extern "C" fn abort() -> ! {
+    use core::arch::asm;
+    loop {
+        unsafe {
+            asm!("wfi");
+        }
+    }
 }
 
 // TODO unit testing