kern: implement uart init + logging

libraries/libmesosphere/include/mesosphere/kern_common.hpp

@@ -23,3 +23,12 @@ namespace ams::kern {
     constexpr size_t PageSize = 4_KB;
 
 }
+
+#ifdef  MESOSPHERE_BUILD_FOR_AUDITING
+#define MESOSPHERE_BUILD_FOR_DEBUGGING
+#endif
+
+#ifdef  MESOSPHERE_BUILD_FOR_DEBUGGING
+#define MESOSPHERE_ENABLE_ASSERTIONS
+#define MESOSPHERE_ENABLE_DEBUG_PRINT
+#endif