为什么stm32f4的中断跳到startup_stm32f40_41xxx.s库中后就跳不出来了

Question

为什么我的中断函数跳到startup_stm32f40_41xxx.s库中后就跳不出来了。
debug到中断初始化之后就动不了了，停止之后发现在startup_stm32f40_41xxx.s中
初始化代码：
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE);  ///ʹÄÜTIM3ʱÖÓ
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

NVIC_InitStructure.NVIC_IRQChannel=TIM1_UP_TIM10_IRQn; //¶¨Ê±Æ÷3ÖжÏ
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x00; //ÇÀÕ¼ÓÅÏȼ¶1
NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x00; //×ÓÓÅÏȼ¶3
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);

TIM_TimeBaseInitStructure.TIM_Period = 10000-1; //×Ô¶¯ÖØ×°ÔØÖµ
TIM_TimeBaseInitStructure.TIM_Prescaler= 8400-1; //¶¨Ê±Æ÷·ÖƵ
TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //ÏòÉϼÆÊýģʽ
TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInitStructure.TIM_RepetitionCounter=0;

TIM_TimeBaseInit(TIM1,&TIM_TimeBaseInitStructure);//³õʼ»¯TIM3

//TIM_ClearFlag(TIM1,TIM_FLAG_Update);
TIM_ITConfig(TIM1,TIM_IT_Update,ENABLE); //ÔÊÐí¶¨Ê±Æ÷3¸üÐÂÖжÏ
TIM_Cmd(TIM1,ENABLE); 

Answer 1

中断服务函数写了吗？可能是初始化的时候进中断了，找不到中断入口