thermopshere: refactor jump-to-kernel ,add single-step code

not working under qemu yet though

thermosphere/src/exceptions.c

@@ -19,6 +19,7 @@
 #include "sysreg_traps.h"
 #include "smc.h"
 #include "core_ctx.h"
+#include "single_step.h"
 
 #include "debug_log.h"
 
@@ -110,6 +111,10 @@ void handleLowerElSyncException(ExceptionStackFrame *frame, ExceptionSyndromeReg
             handleMsrMrsTrap(frame, esr);
             break;
 
+        case Exception_SoftwareStepLowerEl:
+            handleSingleStep(frame, esr);
+            break;
+
         default:
             DEBUG("Lower EL sync exception, EC = 0x%02llx IL=%llu ISS=0x%06llx\n", (u64)esr.ec, esr.il, esr.iss);
             dumpStackFrame(frame, false);