更换3.5.0库的startup_stm32f10x_hd.s也不行实在没有办法。网上查可以REMAP USART3串口使用。于是使用USART3、和库自带的startup_stm32f10x_hd.s编译下载，现象和UART4一样无法进入中断。更换回中断生成的 STM32F10x.s 后成功进入USART3中断。由此判断库自带的startup_stm32f10x_hd.s存在问题。对比STM32F10x.s 和startup_stm32f10x_hd.s文件发现处理XXX_Handler以外还有很多不同的地方。于是把不同的地方改成与STM32F10x.s一样后，再配置UART4就可以进入中断了。

修改完成的代码贴出来：

;******************** (C) COPYRIGHT 2011 STMicroelectronics ********************

;* File Name : startup_stm32f10x_hd.s

;* Author : MCD Application Team

;* Version : V3.5.0

;* Date : 11-March-2011

;* Description : STM32F10x High Density Devices vector table for MDK-ARM

;* toolchain.

;* This module performs:

;* - Set the initial SP

;* - Set the initial PC == Reset_Handler

;* - Set the vector table entries with the exceptions ISR address

;* - Configure the clock system and also configure the external

;* SRAM mounted on STM3210E-EVAL board to be used as data

;* memory (optional, to be enabled by user)

;* - Branches to __main in the C library (which eventually

;* calls main()).

;* After Reset the CortexM3 processor is in Thread mode,

;* priority is Privileged, and the Stack is set to Main.

;* <<< Use Configuration Wizard in Context Menu >>>

;*******************************************************************************

; THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS

; WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.

; AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,

; INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE

; CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING

; INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.

;*******************************************************************************

; Amount of memory (in bytes) allocated for Stack

; Tailor this value to your application needs

; Stack Configuration

; Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>

;

Stack_Size EQU 0x00000200

AREA STACK, NOINIT, READWRITE, ALIGN=3

Stack_Mem SPACE Stack_Size

__initial_sp

; Heap Configuration

; Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>

;

Heap_Size EQU 0x00000000

AREA HEAP, NOINIT, READWRITE, ALIGN=3

__heap_base

Heap_Mem SPACE Heap_Size

__heap_limit

PRESERVE8

THUMB

; Vector Table Mapped to Address 0 at Reset

AREA RESET, DATA, READONLY

EXPORT __Vectors

; EXPORT __Vectors_End

; EXPORT __Vectors_Size

__Vectors DCD __initial_sp ; Top of Stack

DCD Reset_Handler ; Reset Handler

DCD NMI_Handler ; NMI Handler

DCD HardFault_Handler ; Hard Fault Handler

DCD MemManage_Handler ; MPU Fault Handler

DCD BusFault_Handler ; Bus Fault Handler

DCD UsageFault_Handler ; Usage Fault Handler

DCD 0 ; Reserved

DCD 0 ; Reserved

DCD 0 ; Reserved

DCD 0 ; Reserved

DCD SVC_Handler ; SVCall Handler

DCD DebugMon_Handler ; Debug Monitor Handler

DCD 0 ; Reserved

DCD PendSV_Handler ; PendSV Handler

DCD SysTick_Handler ; SysTick Handler

; External Interrupts

DCD WWDG_IRQHandler ; Window Watchdog

DCD PVD_IRQHandler ; PVD through EXTI Line detect

DCD TAMPER_IRQHandler ; Tamper

DCD RTC_IRQHandler ; RTC

DCD FLASH_IRQHandler ; Flash

DCD RCC_IRQHandler ; RCC

DCD EXTI0_IRQHandler ; EXTI Line 0

DCD EXTI1_IRQHandler ; EXTI Line 1

DCD EXTI2_IRQHandler ; EXTI Line 2

DCD EXTI3_IRQHandler ; EXTI Line 3

DCD EXTI4_IRQHandler ; EXTI Line 4

DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1

DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2

DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3

DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4

DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5

DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6

DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7

DCD ADC1_2_IRQHandler ; ADC1 & ADC2

DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX

DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0

DCD CAN1_RX1_IRQHandler ; CAN1 RX1

DCD CAN1_SCE_IRQHandler ; CAN1 SCE

DCD EXTI9_5_IRQHandler ; EXTI Line 9..5

DCD TIM1_BRK_IRQHandler ; TIM1 Break

DCD TIM1_UP_IRQHandler ; TIM1 Update

DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation

DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare

DCD TIM2_IRQHandler ; TIM2

DCD TIM3_IRQHandler ; TIM3

DCD TIM4_IRQHandler ; TIM4

DCD I2C1_EV_IRQHandler ; I2C1 Event

DCD I2C1_ER_IRQHandler ; I2C1 Error

DCD I2C2_EV_IRQHandler ; I2C2 Event

DCD I2C2_ER_IRQHandler ; I2C2 Error

DCD SPI1_IRQHandler ; SPI1

DCD SPI2_IRQHandler ; SPI2

DCD USART1_IRQHandler ; USART1

DCD USART2_IRQHandler ; USART2

DCD USART3_IRQHandler ; USART3

DCD EXTI15_10_IRQHandler ; EXTI Line 15..10

DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line

DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend

DCD TIM8_BRK_IRQHandler ; TIM8 Break

DCD TIM8_UP_IRQHandler ; TIM8 Update

DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation

DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare

DCD ADC3_IRQHandler ; ADC3

DCD FSMC_IRQHandler ; FSMC

DCD SDIO_IRQHandler ; SDIO

DCD TIM5_IRQHandler ; TIM5

DCD SPI3_IRQHandler ; SPI3

DCD UART4_IRQHandler ; UART4

DCD UART5_IRQHandler ; UART5

DCD TIM6_IRQHandler ; TIM6

DCD TIM7_IRQHandler ; TIM7

DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1

DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2

DCD DMA2_Channel3_IRQHandler ; DMA2 Channel3

DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5

AREA |.text|, CODE, READONLY

;__Vectors_End

;__Vectors_Size EQU __Vectors_End - __Vectors

; AREA |.text|, CODE, READONLY

; Reset Handler

Reset_Handler PROC

EXPORT Reset_Handler [WEAK]

IMPORT __main

LDR R0, =__main

BX R0

ENDP

; Dummy Exception Handlers (infinite loops which can be modified)

NMI_Handler PROC

EXPORT NMI_Handler [WEAK]

B .

ENDP

HardFault_Handler\

PROC

EXPORT HardFault_Handler [WEAK]

B .

ENDP

MemManage_Handler\

PROC

EXPORT MemManage_Handler [WEAK]

B .

ENDP

BusFault_Handler\

PROC

EXPORT BusFault_Handler [WEAK]

B .

ENDP

UsageFault_Handler\

PROC

EXPORT UsageFault_Handler [WEAK]

B .

ENDP

SVC_Handler PROC

EXPORT SVC_Handler [WEAK]

B .

ENDP

DebugMon_Handler\

PROC

EXPORT DebugMon_Handler [WEAK]

B .

ENDP

PendSV_Handler PROC

EXPORT PendSV_Handler [WEAK]

B .

ENDP

SysTick_Handler PROC

EXPORT SysTick_Handler [WEAK]

B .

ENDP

Default_Handler PROC

EXPORT WWDG_IRQHandler [WEAK]

EXPORT PVD_IRQHandler [WEAK]

EXPORT TAMPER_IRQHandler [WEAK]

EXPORT RTC_IRQHandler [WEAK]

EXPORT FLASH_IRQHandler [WEAK]

EXPORT RCC_IRQHandler [WEAK]

EXPORT EXTI0_IRQHandler [WEAK]

EXPORT EXTI1_IRQHandler [WEAK]

EXPORT EXTI2_IRQHandler [WEAK]

EXPORT EXTI3_IRQHandler [WEAK]

EXPORT EXTI4_IRQHandler [WEAK]

EXPORT DMA1_Channel1_IRQHandler [WEAK]

EXPORT DMA1_Channel2_IRQHandler [WEAK]

EXPORT DMA1_Channel3_IRQHandler [WEAK]

EXPORT DMA1_Channel4_IRQHandler [WEAK]

EXPORT DMA1_Channel5_IRQHandler [WEAK]

EXPORT DMA1_Channel6_IRQHandler [WEAK]

EXPORT DMA1_Channel7_IRQHandler [WEAK]

EXPORT ADC1_2_IRQHandler [WEAK]

EXPORT USB_HP_CAN1_TX_IRQHandler [WEAK]

EXPORT USB_LP_CAN1_RX0_IRQHandler [WEAK]

EXPORT CAN1_RX1_IRQHandler [WEAK]

EXPORT CAN1_SCE_IRQHandler [WEAK]

EXPORT EXTI9_5_IRQHandler [WEAK]

EXPORT TIM1_BRK_IRQHandler [WEAK]

EXPORT TIM1_UP_IRQHandler [WEAK]

EXPORT TIM1_TRG_COM_IRQHandler [WEAK]

EXPORT TIM1_CC_IRQHandler [WEAK]

EXPORT TIM2_IRQHandler [WEAK]

EXPORT TIM3_IRQHandler [WEAK]

EXPORT TIM4_IRQHandler [WEAK]

EXPORT I2C1_EV_IRQHandler [WEAK]

EXPORT I2C1_ER_IRQHandler [WEAK]

EXPORT I2C2_EV_IRQHandler [WEAK]

EXPORT I2C2_ER_IRQHandler [WEAK]

EXPORT SPI1_IRQHandler [WEAK]

EXPORT SPI2_IRQHandler [WEAK]

EXPORT USART1_IRQHandler [WEAK]

EXPORT USART2_IRQHandler [WEAK]

EXPORT USART3_IRQHandler [WEAK]

EXPORT EXTI15_10_IRQHandler [WEAK]

EXPORT RTCAlarm_IRQHandler [WEAK]

EXPORT USBWakeUp_IRQHandler [WEAK]

EXPORT TIM8_BRK_IRQHandler [WEAK]

EXPORT TIM8_UP_IRQHandler [WEAK]

EXPORT TIM8_TRG_COM_IRQHandler [WEAK]

EXPORT TIM8_CC_IRQHandler [WEAK]

EXPORT ADC3_IRQHandler [WEAK]

EXPORT FSMC_IRQHandler [WEAK]

EXPORT SDIO_IRQHandler [WEAK]

EXPORT TIM5_IRQHandler [WEAK]

EXPORT SPI3_IRQHandler [WEAK]

EXPORT UART4_IRQHandler [WEAK]

EXPORT UART5_IRQHandler [WEAK]

EXPORT TIM6_IRQHandler [WEAK]

EXPORT TIM7_IRQHandler [WEAK]

EXPORT DMA2_Channel1_IRQHandler [WEAK]

EXPORT DMA2_Channel2_IRQHandler [WEAK]

EXPORT DMA2_Channel3_IRQHandler [WEAK]

EXPORT DMA2_Channel4_5_IRQHandler [WEAK]

WWDG_IRQHandler

PVD_IRQHandler

TAMPER_IRQHandler

RTC_IRQHandler

FLASH_IRQHandler

RCC_IRQHandler

EXTI0_IRQHandler

EXTI1_IRQHandler

EXTI2_IRQHandler

EXTI3_IRQHandler

EXTI4_IRQHandler

DMA1_Channel1_IRQHandler

DMA1_Channel2_IRQHandler

DMA1_Channel3_IRQHandler

DMA1_Channel4_IRQHandler

DMA1_Channel5_IRQHandler

DMA1_Channel6_IRQHandler

DMA1_Channel7_IRQHandler

ADC1_2_IRQHandler

USB_HP_CAN1_TX_IRQHandler

USB_LP_CAN1_RX0_IRQHandler

CAN1_RX1_IRQHandler

CAN1_SCE_IRQHandler

EXTI9_5_IRQHandler

TIM1_BRK_IRQHandler

TIM1_UP_IRQHandler

TIM1_TRG_COM_IRQHandler

TIM1_CC_IRQHandler

TIM2_IRQHandler

TIM3_IRQHandler

TIM4_IRQHandler

I2C1_EV_IRQHandler

I2C1_ER_IRQHandler

I2C2_EV_IRQHandler

I2C2_ER_IRQHandler

SPI1_IRQHandler

SPI2_IRQHandler

USART1_IRQHandler

USART2_IRQHandler

USART3_IRQHandler

EXTI15_10_IRQHandler

RTCAlarm_IRQHandler

USBWakeUp_IRQHandler

TIM8_BRK_IRQHandler

TIM8_UP_IRQHandler

TIM8_TRG_COM_IRQHandler

TIM8_CC_IRQHandler

ADC3_IRQHandler

FSMC_IRQHandler

SDIO_IRQHandler

TIM5_IRQHandler

SPI3_IRQHandler

UART4_IRQHandler

UART5_IRQHandler

TIM6_IRQHandler

TIM7_IRQHandler

DMA2_Channel1_IRQHandler

DMA2_Channel2_IRQHandler

DMA2_Channel3_IRQHandler

DMA2_Channel4_5_IRQHandler

B .

ENDP

ALIGN

; User Initial Stack & Heap

IF :DEF:__MICROLIB

EXPORT __initial_sp

EXPORT __heap_base

EXPORT __heap_limit

ELSE

IMPORT __use_two_region_memory

EXPORT __user_initial_stackheap

__user_initial_stackheap

LDR R0, = Heap_Mem

LDR R1, =(Stack_Mem + Stack_Size)

LDR R2, = (Heap_Mem + Heap_Size)

LDR R3, = Stack_Mem

BX LR

ALIGN

ENDIF

END