图解WinCE6.0下的内核驱动和用户驱动

在《WinCE驱动程序的分类》中曾提到，WinCE6.0的流驱动既可以加载到内核态也可以加载到用户态。下面通过一组图片简单说明一下这两种驱动的关系。

首先编写一个流驱动WCEDrv，代码如下。

代码
#include <windows.h>
 
 extern "C"
 BOOL WINAPI DllMain(HANDLE hinstDLL, DWORD dwReason, LPVOID lpvReserved)
 {
     UNREFERENCED_PARAMETER(lpvReserved);
 
     switch(dwReason) {
     case DLL_PROCESS_ATTACH:
         DisableThreadLibraryCalls((HMODULE) hinstDLL);
         break;
     case DLL_PROCESS_DETACH:
         break;
     };
     return TRUE;
 }
 
 
 extern "C"
 DWORD Init(LPCTSTR pContext, DWORD dwBusContext)
 {
     RETAILMSG(1,(_T("Init(%s, %x)"),pContext,dwBusContext));
     
     PBYTE pBuffer = new BYTE[4096*1024];     
     RETAILMSG(1,(TEXT("pBuffer(%x)\r\n"),pBuffer));
 
     return  (DWORD)pBuffer;
 }
 
 
 extern "C"
 BOOL Deinit(DWORD hDeviceContext)
 {
     RETAILMSG(1,(_T("Deinit(%x)\r\n"),hDeviceContext));
     
     PBYTE pBuffer = (PBYTE)hDeviceContext;
     if (pBuffer)
     {
         delete[] pBuffer;
     }    
 
     return TRUE;
 }
 
 
 extern "C"
 void PowerUp(DWORD hDeviceContext)
 {
 }
 
 extern "C"
 void PowerDown(DWORD hDeviceContext)
 {
 }
 
 extern "C"
 DWORD Open(DWORD hDeviceContext, DWORD AccessCode, DWORD ShareMode)
 {
     RETAILMSG(1,(_T("Open(%x, 0x%x, 0x%x)\r\n"),hDeviceContext, AccessCode, ShareMode));
 
     return hDeviceContext;
 }
 
 extern "C"
 BOOL Close(DWORD hOpenContext)
 {
     RETAILMSG(1,(_T("Close(%x)\r\n"),hOpenContext));
 
     return TRUE;
 }
 
 extern "C"
 BOOL IOControl(DWORD hOpenContext, DWORD dwCode, PBYTE pBufIn, DWORD dwLenIn
                , PBYTE pBufOut, DWORD dwLenOut, PDWORD pdwActualOut)
 {
     UNREFERENCED_PARAMETER(hOpenContext);
     UNREFERENCED_PARAMETER(dwCode);
     UNREFERENCED_PARAMETER(pBufIn);
     UNREFERENCED_PARAMETER(dwLenIn);
     UNREFERENCED_PARAMETER(pBufOut);
     UNREFERENCED_PARAMETER(dwLenOut);
     UNREFERENCED_PARAMETER(pdwActualOut);
 
     SetLastError(ERROR_INVALID_FUNCTION);
     return FALSE;
 }
 
 extern "C"
 DWORD Read(DWORD hOpenContext, LPVOID pBuffer, DWORD Count)
 {
     RETAILMSG(1,(_T("Read(%x, %x, 0x%x)\r\n"),hOpenContext, pBuffer, Count));
 
     return TRUE;
 }
 
 extern "C"
 DWORD Write(DWORD hOpenContext, LPCVOID pBuffer, DWORD Count)
 {
     RETAILMSG(1,(_T("Write(%x, %x, 0x%x)\r\n"),hOpenContext, pBuffer, Count));
 
     return TRUE;
 }
 
 extern "C"
 DWORD Seek(DWORD hOpenContext, long Amount, WORD Type)
 {
     UNREFERENCED_PARAMETER(hOpenContext);
     UNREFERENCED_PARAMETER(Amount);
     UNREFERENCED_PARAMETER(Type);
 
     SetLastError(ERROR_NOT_SUPPORTED);
     return -1;
 }

其对应的注册表文件内容如下。

注册表
[HKEY_LOCAL_MACHINE\Drivers\WCEDrv1]
     "Prefix"="AAA"
     "Dll"="WCEDrv.dll"
     "Index"=dword:1
     "Flags"=dword:8        ; DEVFLAGS_NAKEDENTRIES
     "Order"=dword:0
 
 [HKEY_LOCAL_MACHINE\Drivers\WCEDrv2]
     "Prefix"="BBB"
     "Dll"="WCEDrv.dll"
     "Index"=dword:1
     "Flags"=dword:8        ; DEVFLAGS_NAKEDENTRIES
     "Order"=dword:0
 
 [HKEY_LOCAL_MACHINE\Drivers\WCEDrv3]
     "Prefix"="CCC"
     "Dll"="WCEDrv.dll"
     "Index"=dword:1
     "Flags"=dword:18    ; DEVFLAGS_LOAD_AS_USERPROC | DEVFLAGS_NAKEDENTRIES
     "Order"=dword:0
 
 [HKEY_LOCAL_MACHINE\Drivers\WCEDrv4]
     "Prefix"="DDD"
     "Dll"="WCEDrv.dll"
     "Index"=dword:1
     "Flags"=dword:18    ; DEVFLAGS_LOAD_AS_USERPROC | DEVFLAGS_NAKEDENTRIES
     "Order"=dword:0