repair running error by remove interrupt stack,and repair the uart output problems

Ubiquitous/XiUOS/kernel/memory/byte_manage.c

@@ -1222,8 +1222,9 @@ void ShowBuddy(void)
     	};
 	}
     
-    KPrintf("\n\033[41;1mlist extern memory information\033[0m\n");
+    
 #ifdef MEM_EXTERN_SRAM
+	KPrintf("\n\033[41;1mlist extern memory information\033[0m\n");
 	for(i = 0; i < EXTSRAM_MAX_NUM; i++) {
 		if(NONE != ExtByteManager[i].done){
 			KPrintf("\nlist extern sram[%d] memory information\n\n",i);

Ubiquitous/XiUOS/kernel/thread/tick.c

@@ -74,7 +74,9 @@ void TickAndTaskTimesliceUpdate(void)
     RoundRobinTaskTimesliceUpdate(task);
 #elif defined (SCHED_POLICY_RR_REMAINSLICE)
     task = GetKTaskDescriptor();
-    RoundRobinRemainTaskTimesliceUpdate(task);
+    if(task){
+        RoundRobinRemainTaskTimesliceUpdate(task);
+    }
 #endif
     CheckTaskDelay();
 #ifdef KERNEL_SOFTTIMER