diff --git a/bootloader/start.S b/bootloader/start.S
index a380361..3d110ec 100644
--- a/bootloader/start.S
+++ b/bootloader/start.S
@@ -37,6 +37,11 @@ Reset_Handler:
     blo 1b
 2:
     bl  SystemInit
+    /* set vtor and enable interrupt */
+    ldr r0, =0xE000ED08
+    ldr r1, =0
+    str r1, [r0]
+    cpsie i
     bl  main
     b   .
 .size  Reset_Handler, .-Reset_Handler
@@ -66,7 +71,7 @@ g_pfnVectors:
     .word  DebugMon_Handler
     .word  0
     .word  PendSV_Handler
-    .word  SysTick_Handler
+    .word  HAL_IncTick //SysTick_Handler
 
     /* External Interrupts */
     .word     WWDG_IRQHandler                   /* Window WatchDog              */