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

通过驱动调试助手动态加载该驱动，在加载时，根据注册表中的设置，分别加载两个到内核空间和用户空间。