Add test architecture

arch/test/src/interrupt.rs

@@ -0,0 +1,24 @@
+//! Interrupt instructions
+
+static mut INTERRUPTS_ENABLED: bool = false;
+
+/// Clear interrupts
+#[inline(always)]
+pub unsafe fn clear_interrupts() {
+    println!("CLEAR INTERRUPTS");
+    INTERRUPTS_ENABLED = false;
+}
+
+/// Set interrupts
+#[inline(always)]
+pub unsafe fn set_interrupts() {
+    println!("SET INTERRUPTS");
+    INTERRUPTS_ENABLED = true;
+}
+
+/// Halt instruction
+#[inline(always)]
+pub unsafe fn halt() {
+    assert!(INTERRUPTS_ENABLED);
+    ::std::thread::yield_now();
+}