Index: kernel/generic/src/udebug/udebug_ops.c
===================================================================
--- kernel/generic/src/udebug/udebug_ops.c	(revision 86bbca413cd4472a041d8633c827dff484ee576a)
+++ kernel/generic/src/udebug/udebug_ops.c	(revision 94e3a036175ccd11c8c097a5202b483a00cde423)
@@ -167,5 +167,5 @@
  * @param call The BEGIN call we are servicing.
  *
- * @return EOK or negative error code.
+ * @return 0 (OK, but not done yet), 1 (done) or negative error code.
  *
  */
@@ -184,4 +184,13 @@
 	TASK->udebug.begin_call = call;
 	TASK->udebug.debugger = call->sender;
+	
+	int reply;
+	
+	if (TASK->udebug.not_stoppable_count == 0) {
+		TASK->udebug.dt_state = UDEBUG_TS_ACTIVE;
+		TASK->udebug.begin_call = NULL;
+		reply = 1;  /* immediate reply */
+	} else
+		reply = 0;  /* no reply */
 	
 	/* Set udebug.active on all of the task's userspace threads. */
@@ -198,5 +207,5 @@
 	
 	mutex_unlock(&TASK->udebug.lock);
-	return EOK;
+	return reply;
 }