Enable interrupts and halt CPU

src/hulk/hulk.d

@@ -16,6 +16,7 @@ import hulk.pci;
 import hulk.gdt;
 import hulk.idt;
 import hos.cpu;
+import ldc.llvmasm;
 
 extern extern(C) __gshared ubyte _hulk_total_size;
 
@@ -46,8 +47,10 @@ void hulk_start()
 
     hippo.initialize(&hulk_header);
     pci.initialize();
+    sti();
 
     for (;;)
     {
+        hlt();
     }
 }