Check that needed ACPI tables are found

src/hulk/acpi.d

@@ -161,6 +161,14 @@ struct Acpi
                 mcfg.initialize();
             }
         }
+        if (madt == null)
+        {
+            Klog.fatal_error("MADT table not found");
+        }
+        if (mcfg == null)
+        {
+            Klog.fatal_error("MCFG table not found");
+        }
     }
 
     private static void map_table(ulong address, ulong length)