diff --git a/nemu/src/device/timer.c b/nemu/src/device/timer.c
index 9e680ec..e53fe4b 100644
--- a/nemu/src/device/timer.c
+++ b/nemu/src/device/timer.c
@@ -19,13 +19,12 @@
 
 static uint32_t *rtc_port_base = NULL;
 
-__attribute_noinline__
 static void rtc_io_handler(uint32_t offset, int len, bool is_write) {
   assert(offset == 0 || offset == 4);
   if (!is_write && offset == 4) {
     uint64_t us = get_time();
-    ((volatile uint32_t*)rtc_port_base)[0] = (uint32_t)us;
-    ((volatile uint32_t*)rtc_port_base)[1] = us >> 32;
+    rtc_port_base[0] = (uint32_t)us;
+    rtc_port_base[1] = us >> 32;
   }
 }
 
@@ -40,6 +39,7 @@ static void timer_intr() {
 
 void init_timer() {
   rtc_port_base = (uint32_t *)new_space(8);
+  get_time();
 #ifdef CONFIG_HAS_PORT_IO
   add_pio_map ("rtc", CONFIG_RTC_PORT, rtc_port_base, 8, rtc_io_handler);
 #else