windows ce RS232C串行口驱动程序设计

实验5 RS232C串行口驱动程序设计实验目的掌握RS232串行口设备驱动程序的编写方法，实现串行口的初始化、中断管理、发送与接收处理的程序设计技巧。

实验环境⏹操作系统：windows 2000以上版本，要求安装.NET Framework 1.1⏹软件工具列表：⏹Microsoft ActiveSyn 4.5；⏹Platform Builder 5.0；实验学时2学时，必做实验。

实验内容理解驱动程序的原理与功能，掌握流式接口驱动程序的结构、编写、加载及调试过程预备知识驱动程序是对底层硬件的抽象。

应用程序开发者不需要真正理解底层驱动的工作原理，他们只需要通过Windows CE提供的API函数，就可以直接与硬件进行交互。

例如，如果应用程序要对串口进行操作，只需要：1.在COMx上调用CreateFile( )2.调用WriteFile( ) 往串口写数据3.调用CloseHandle( ) 关闭串口对于其他类型的API也是一样的。

如果我们需要向显示器输出，我们只需要调用PolyLine( ), 或者MoveToEx( ), LineTo( )等函数，而不需要理解显示器的真正工作原理。

在Windows CE中，驱动就是一个简单的用户态动态链接库（DLL），DLL 会导出一些公共的接口，DLL被父进程（通常是device.exe或者gwes.exe）加载，然后，父进程通过DLL导出的接口调用DLL。

流式接口的驱动程序导出一系列大家熟知的接口。

还拿串口驱动当例子。

我们希望可以往串口读写数据，因此，我们希望驱动程序可以导出Open, Close, Read, 和Write接口。

此外，流式接口的驱动程序还导出如下函数：PowerUp, PowerDown, IO Control, Init, 和DeInit.实验步骤一.、编写流式接口的驱动程序1.打开Platform Builder。

2.利用Platform Wizard创建新的平台3.在Platform Builder中选择“File”->“New Project or File”，创建一个“Windows CE Dynamic link library”项目，项目的名称填写“My Driver”。

4.向导的第一步选择“A Simple Windows CE DLL”。

Platform Builder会为我们生成DLL框架代码。

5.修改Platform Builder生成的DllMain函数，如下：BOOL APIENTRY DllMain( HANDLE hModule,DWORD ul_reason_for_call,LPVOID lpReserved){switch ( ul_reason_for_call ){case DLL_PROCESS_ATTACH:OutputDebugString(L"MyDriver - DLL_PROCESS_ATTACH\n");break;case DLL_PROCESS_DETACH:OutputDebugString(L"MyDriver - DLL_PROCESS_DETACH\n");break;case DLL_THREAD_ATTACH:OutputDebugString(L"MyDriver - DLL_THREAD_ATTACH\n");break;case DLL_THREAD_DETACH:OutputDebugString(L"MyDriver - DLL_THREAD_DETACH\n");break; }return TRUE;}6.添加流式接口驱动的导出函数前置声明，如下：DWORD DEM_Init(LPCTSTR pContext, LPCVOID lpvBusContext);BOOL DEM_Deinit( DWORD hDeviceContext );DWORD DEM_Open( DWORD hDeviceContext, DWORD AccessCode, DWORD ShareMode );BOOL DEM_Close( DWORD hOpenContext );BOOL DEM_IOControl( DWORD hOpenContext, DWORD dwCode, PBYTE pBufIn, DWORD dwLenIn, PBYTE pBufOut, DWORD dwLenOut, PDWORD pdwActualOut ); void DEM_PowerUp( DWORD hDeviceContext );void DEM_PowerDown( DWORD hDeviceContext );DWORD DEM_Read( DWORD hOpenContext, LPVOID pBuffer, DWORD Count ); DWORD DEM_Write( DWORD hOpenContext, LPCVOID pBuffer, DWORD Count ); DWORD DEM_Seek( DWORD hOpenContext, long Amount, WORD Type );#define IOCTL_DRIVER_DEMO 42// Not exposed by the Device Drivervoid DBGOut(DWORD dwValue);HANDLE hMem=NULL;DWORD dwCount;7.添加导出函数的具体实现，代码如下：DWORD DEM_Init( LPCTSTR pContext, LPCVOID lpvBusContext){OutputDebugString(L"MyDriver - DEM_Init - Context: ");OutputDebugString(pContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_Init\n");return 0x1234;}BOOL DEM_Deinit( DWORD hDeviceContext ){OutputDebugString(L"MyDriver - DEM_Deinit\n");OutputDebugString(L"MyDriver - ~ DEM_Deinit\n");return TRUE;}DWORD DEM_Open( DWORD hDeviceContext, DWORD AccessCode, DWORD ShareMode ){OutputDebugString(L"MyDriver - DEM_Open\n");OutputDebugString(L"hDeviceContext - ");DBGOut(hDeviceContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_Open\n");return 0x5678;}BOOL DEM_Close( DWORD hOpenContext ){OutputDebugString(L"MyDriver - DEM_Close\n");OutputDebugString(L"hOpenContext - ");DBGOut(hOpenContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_Close\n");return TRUE;}BOOL DEM_IOControl( DWORD hOpenContext, DWORD dwCode, PBYTE pBufIn, DWORD dwLenIn, PBYTE pBufOut, DWORD dwLenOut, PDWORD pdwActualOut ) {OutputDebugString(L"MyDriver - DEM_IOControl\n");OutputDebugString(L"hOpenContext - ");DBGOut(hOpenContext);OutputDebugString(L"\n");switch (dwCode) {case IOCTL_DRIVER_DEMO:{OutputDebugString(L"DRIVER DEMO IOCTL...\n");// reverse the string...HANDLE hTemp=LocalAlloc(LPTR,dwLenIn+1);memset(hTemp,0x00,dwLenIn+1);TCHAR *tcOut=(TCHAR*)hTemp;TCHAR *tcIn=(TCHAR*)pBufIn;DWORD dwChars=dwLenIn/2;for (DWORD x=0;x < dwChars;x++) {tcOut[x]=tcIn[dwChars-x-1];}memcpy(pBufOut,hTemp,dwLenIn);LocalFree(hTemp);*pdwActualOut=dwLenIn;}break;default:OutputDebugString(L"Unknown IOCTL\n");break;}OutputDebugString(L"MyDriver - ~ DEM_IOControl\n");return TRUE;}void DEM_PowerUp( DWORD hDeviceContext ){OutputDebugString(L"MyDriver - DEM_PowerUp\n");OutputDebugString(L"hDeviceContext - ");DBGOut(hDeviceContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_PowerUp\n");}void DEM_PowerDown( DWORD hDeviceContext ){OutputDebugString(L"MyDriver - DEM_PowerDown\n");OutputDebugString(L"hDeviceContext - ");DBGOut(hDeviceContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_PowerDown\n");DWORD DEM_Read( DWORD hOpenContext, LPVOID pBuffer, DWORD Count ) {DWORD dwRetCount=0xffff; // default to errorOutputDebugString(L"MyDriver - DEM_Read\n");OutputDebugString(L"hOpenContext - ");DBGOut(hOpenContext);OutputDebugString(L"\n");if (NULL != hMem) {dwRetCount=dwCount;memcpy(pBuffer,hMem,dwCount);}OutputDebugString(L"MyDriver - ~ DEM_Read\n");return dwRetCount;}DWORD DEM_Write( DWORD hOpenContext, LPCVOID pBuffer, DWORD Count ) {OutputDebugString(L"MyDriver - DEM_Write\n");OutputDebugString(L"hOpenContext - ");DBGOut(hOpenContext);OutputDebugString(L"\n");if (NULL != hMem) {LocalFree(hMem);}hMem=LocalAlloc(LPTR,Count);memcpy(hMem,pBuffer,Count);dwCount=Count;OutputDebugString(L"MyDriver - ~ DEM_Write\n");return Count;}DWORD DEM_Seek( DWORD hOpenContext, long Amount, WORD Type ){OutputDebugString(L"MyDriver - DEM_Seek\n");OutputDebugString(L"hOpenContext - ");DBGOut(hOpenContext);OutputDebugString(L"\n");OutputDebugString(L"MyDriver - ~ DEM_Seek\n");return 0;}void DBGOut(DWORD dwValue){TCHAR tcTemp[10];wsprintf(tcTemp,L"%ld",dwValue);OutputDebugString(tcTemp);}8.添加导出函数的定义。