【.Net Micro Framework PortingKit - 04】修改启动代码&重写向量表

在上三篇《移植初步：环境搭建》《STM3210E平台构建》《调试初步：点亮LED灯》文章中，我们介绍了如何搭建开发环境，并初步写了测试代码，下一步我们将根据Cortex-M3的架构特点，修改启动代码和重写中断向量表。

   Cortex-M3的中断架构非常有特色，芯片内建一个嵌套向量中断控制器NVIC(Nested Vectored Interrupt Controller)，它与内核是紧耦合的，提供如下的功能：可嵌套中断支持，向量中断支持，动态优先级调整支持，中断延迟大大缩短，中断可屏蔽。NVIC 支持240 个优先级可动态配置的中断，每个中断的优先级有256 个选择。低延迟的中断处理可以通过紧耦合的NVIC 和处理器内核接口来实现，让新进的中断可以得到有效的处理。NVIC通过时刻关注压栈（嵌套）中断来实现中断的末尾连锁（tail-chaining）。

   .Net Micro Framework的中断处理构建在Cortex-M3的中断架构之上，将大大提升的.Net Micro Framework的实时性能，不过由于架构全新，需要大幅度改写.Net Micro Framework原有中断处理代码，不破不立，这对性能有所诟病的.Net Micro Framework也许是个好事情。

    下面就新中断架构，进行代码改写。

 

    1、修改FirstEntry.s代码

    由于废弃了.\devicecode\cores\arm\assemblycode\thumb2\rvd_s\VectorsHanlers.s 所以为了编译通过，我们要在同目录下的FirstEntry.s中添加一些代码，

在文件头添加如下代码：    

    

EXPORT  HARD_Breakpoint

    ;IMPORT  HARD_Breakpoint_Handler   ; HARD_Breakpoint_Handler(unsigned int*, unsigned int, unsigned int)

 

 

在文件尾“END”命令前添加如下代码：

  

;AREA ||i.HARD_Breakpoint||, CODE, READONLY     ; void HARD_Breakpoint()

RD_Breakpoint

  ; on entry, were are being called from C/C++ in system mode

  ;b       HARD_Breakpoint_Handler     ; address of vector routine in C to jump to, never expect to return

 

 

    2、重写中断向量表（VectorsTrampolines.s）

        重写同目录下的VectorsTrampolines.s文件为如下内容：

   

  ; 导入异常或中断处理程序

         IMPORT  NMIException

         IMPORT  HardFaultException

         IMPORT  MemManageException

         IMPORT  BusFaultException

         IMPORT  UsageFaultException

         IMPORT  SVCHandler

         IMPORT  DebugMonitor

         IMPORT  PendSVC

         IMPORT  SysTickHandler

         IMPORT  WWDG_IRQHandler

         IMPORT  PVD_IRQHandler

         IMPORT  TAMPER_IRQHandler

         IMPORT  RTC_IRQHandler

         IMPORT  FLASH_IRQHandler

         IMPORT  RCC_IRQHandler

         IMPORT  EXTI0_IRQHandler

         IMPORT  EXTI1_IRQHandler

         IMPORT  EXTI2_IRQHandler

         IMPORT  EXTI3_IRQHandler

         IMPORT  EXTI4_IRQHandler

         IMPORT  DMA1_Channel1_IRQHandler

         IMPORT  DMA1_Channel2_IRQHandler

         IMPORT  DMA1_Channel3_IRQHandler

         IMPORT  DMA1_Channel4_IRQHandler

         IMPORT  DMA1_Channel5_IRQHandler

         IMPORT  DMA1_Channel6_IRQHandler

         IMPORT  DMA1_Channel7_IRQHandler

         IMPORT  ADC1_2_IRQHandler

         IMPORT  USB_HP_CAN_TX_IRQHandler

         IMPORT  USB_LP_CAN_RX0_IRQHandler

         IMPORT  CAN_RX1_IRQHandler

         IMPORT  CAN_SCE_IRQHandler

         IMPORT  EXTI9_5_IRQHandler

         IMPORT  TIM1_BRK_IRQHandler

         IMPORT  TIM1_UP_IRQHandler

         IMPORT  TIM1_TRG_COM_IRQHandler

         IMPORT  TIM1_CC_IRQHandler

         IMPORT  TIM2_IRQHandler

         IMPORT  TIM3_IRQHandler

         IMPORT  TIM4_IRQHandler

         IMPORT  I2C1_EV_IRQHandler

         IMPORT  I2C1_ER_IRQHandler

         IMPORT  I2C2_EV_IRQHandler

         IMPORT  I2C2_ER_IRQHandler

         IMPORT  SPI1_IRQHandler

         IMPORT  SPI2_IRQHandler

         IMPORT  USART1_IRQHandler

         IMPORT  USART2_IRQHandler

         IMPORT  USART3_IRQHandler

         IMPORT  EXTI15_10_IRQHandler

         IMPORT  RTCAlarm_IRQHandler

         IMPORT  USBWakeUp_IRQHandler

         IMPORT  TIM8_BRK_IRQHandler

         IMPORT  TIM8_UP_IRQHandler

         IMPORT  TIM8_TRG_COM_IRQHandler

         IMPORT  TIM8_CC_IRQHandler

         IMPORT  ADC3_IRQHandler

         IMPORT  FSMC_IRQHandler

         IMPORT  SDIO_IRQHandler

         IMPORT  TIM5_IRQHandler

         IMPORT  SPI3_IRQHandler

         IMPORT  UART4_IRQHandler

         IMPORT  UART5_IRQHandler

         IMPORT  TIM6_IRQHandler

         IMPORT  TIM7_IRQHandler

         IMPORT  DMA2_Channel1_IRQHandler

         IMPORT  DMA2_Channel2_IRQHandler

         IMPORT  DMA2_Channel3_IRQHandler

         IMPORT  DMA2_Channel4_5_IRQHandler





    EXPORT  ARM_Vectors



    IMPORT  StackTop

    IMPORT  EntryPoint



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



    AREA |.text|, CODE, READONLY



    ;向量表

ARM_Vectors

         DCD  StackTop                   ; Top of Stack  栈顶

         DCD  EntryPoint                                    ; 复位

         DCD  NMIException

         DCD  HardFaultException

         DCD  MemManageException

         DCD  BusFaultException

         DCD  UsageFaultException

         DCD  0                 ; Reserved

         DCD  0                 ; Reserved

         DCD  0                 ; Reserved

         DCD  0                 ; Reserved

         DCD  SVCHandler

         DCD  DebugMonitor

         DCD  0                 ; Reserved

         DCD  PendSVC

         DCD  SysTickHandler

         DCD  WWDG_IRQHandler

         DCD  PVD_IRQHandler

         DCD  TAMPER_IRQHandler

         DCD  RTC_IRQHandler

         DCD  FLASH_IRQHandler

         DCD  RCC_IRQHandler

         DCD  EXTI0_IRQHandler

         DCD  EXTI1_IRQHandler

         DCD  EXTI2_IRQHandler

         DCD  EXTI3_IRQHandler

         DCD  EXTI4_IRQHandler

         DCD  DMA1_Channel1_IRQHandler

         DCD  DMA1_Channel2_IRQHandler

         DCD  DMA1_Channel3_IRQHandler

         DCD  DMA1_Channel4_IRQHandler

         DCD  DMA1_Channel5_IRQHandler

         DCD  DMA1_Channel6_IRQHandler

         DCD  DMA1_Channel7_IRQHandler

         DCD  ADC1_2_IRQHandler

         DCD  USB_HP_CAN_TX_IRQHandler

         DCD  USB_LP_CAN_RX0_IRQHandler

         DCD  CAN_RX1_IRQHandler

         DCD  CAN_SCE_IRQHandler

         DCD  EXTI9_5_IRQHandler

         DCD  TIM1_BRK_IRQHandler

         DCD  TIM1_UP_IRQHandler

         DCD  TIM1_TRG_COM_IRQHandler

         DCD  TIM1_CC_IRQHandler

         DCD  TIM2_IRQHandler

         DCD  TIM3_IRQHandler

         DCD  TIM4_IRQHandler

         DCD  I2C1_EV_IRQHandler

         DCD  I2C1_ER_IRQHandler

         DCD  I2C2_EV_IRQHandler

         DCD  I2C2_ER_IRQHandler

         DCD  SPI1_IRQHandler

         DCD  SPI2_IRQHandler

         DCD  USART1_IRQHandler

         DCD  USART2_IRQHandler

         DCD  USART3_IRQHandler

         DCD  EXTI15_10_IRQHandler

         DCD  RTCAlarm_IRQHandler

         DCD  USBWakeUp_IRQHandler

         DCD  TIM8_BRK_IRQHandler

         DCD  TIM8_UP_IRQHandler

         DCD  TIM8_TRG_COM_IRQHandler

         DCD  TIM8_CC_IRQHandler

         DCD  ADC3_IRQHandler

         DCD  FSMC_IRQHandler

         DCD  SDIO_IRQHandler

         DCD  TIM5_IRQHandler

         DCD  SPI3_IRQHandler

         DCD  UART4_IRQHandler

         DCD  UART5_IRQHandler

         DCD  TIM6_IRQHandler

         DCD  TIM7_IRQHandler

         DCD  DMA2_Channel1_IRQHandler

         DCD  DMA2_Channel2_IRQHandler

         DCD  DMA2_Channel3_IRQHandler

         DCD  DMA2_Channel4_5_IRQHandler





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



    END

3、新建VectorsHandler_Temp库文件

    在.\DeviceCode\Targets\Native\CortexM3\DeviceCode目录下，新建目录VectorsHandler_Temp，并新建两个文件dotNetMF.proj（编译配置，可参见其它同类文件），VectorsHandler_Temp.c（空的中断处理函数）。

 

    VectorsHandler_Temp.c的内容如下：

   

void NMIException(void) {}

    void HardFaultException(void){while (1);}

    void MemManageException(void){while (1);}

    void BusFaultException(void){while (1);}

    void UsageFaultException(void){while (1);}

    void DebugMonitor(void){}

    void SVCHandler(void){}



    // 省略部分代码 .....



    void TIM6_IRQHandler(void){}

    void TIM7_IRQHandler(void){}

    void DMA2_Channel1_IRQHandler(void){}

    void DMA2_Channel2_IRQHandler(void){}

    void DMA2_Channel3_IRQHandler(void){}

    void DMA2_Channel4_5_IRQHandler(void){}

 

以上函数为暂且为空，以后我们在根据需要再添加相应的中断处理代码。
4、dotNetMF.proj文件调整

   （1）对.\DeviceCode\cores\arm\dotNetMF.proj文件做如下调整：

 

<ItemGroup Condition="'$(INSTRUCTION_SET)'=='thumb2'">

   <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\FirstEntry.s" />

   <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\IDelayLoop.s" />

   <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\Sampling_Profiler_RAM.s" />

   <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\VectorsHandlers.s" />

   <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\VectorsTrampolines.s" />

 </ItemGroup>

  修改为：

  

<ItemGroup Condition="'$(INSTRUCTION_SET)'=='thumb2'">

    <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\FirstEntry.s" />

    <Compile Include="AssemblyCode\thumb2\$(AS_SUBDIR)\VectorsTrampolines.s" />

  </ItemGroup>



  <ItemGroup>

    <HFiles Include="..\..\Initialization\MasterConfig.h" />

    <Compile Include="Diagnostics\Aborts.cpp" />

    <Compile Include="Diagnostics\FIQ_Profiler.cpp" />

    <Compile Include="Diagnostics\RamTest.cpp" />

    <Compile Include="Diagnostics\RamTest.h" />

    <LIB_FIRSTENTRY_OBJ Include="$(OBJ_DIR)\FirstEntry.$(OBJ_EXT)" />

  </ItemGroup>

  修改为：

  

<ItemGroup>

    <LIB_FIRSTENTRY_OBJ Include="$(OBJ_DIR)\FirstEntry.$(OBJ_EXT)" />

  </ItemGroup>

 

  （2）在.\Solutions\STM3210E\NativeSample\NativeSample.proj文件中添加如下内容：

 

<ItemGroup>

   <RequiredProjects Include="$(SPOCLIENT)\DeviceCode\Targets\Native\CortexM3\DeviceCode\VectorsHandler_Temp\dotNetMF.proj" />

   <DriverLibs Include="VectorsHandler_Temp.$(LIB_EXT)" />

 </ItemGroup>

5、编译

   编译我们的代码，看看是否能编译成功。编译成功后，在用MDK下载的开发板试一试，如果运行正常，这一步工作将告一段落。下一步我们将编写SRAM初始化代码和设置NVIC中断表偏移。