regsample.cpp

windows 2000/XP WDM设备驱动程序开发 附书光盘 武安河著

// RegSample.cpp
//
// Generated by DriverWizard version DriverStudio 3.1.0 (Build 1722)
// Requires Compuware's DriverWorks classes
//

#define VDW_MAIN

#include <vdw.h>
#include "RegSample.h"
#include "RegSampleDevice.h"

#pragma hdrstop("RegSample.pch")

// Generated by DriverWizard version DriverStudio 3.1.0 (Build 1722)

// Set a default 32-bit tag value to be stored with each heap block
// allocated by operator new. Use BoundsChecker to view the memory pool.
// This value can be overridden using the global function SetPoolTag().
POOLTAG DefaultPoolTag('SgeR');

// Create the global driver trace object
// TODO:	Use KDebugOnlyTrace if you want trace messages
//			to appear only in debug builds.  Use KTrace if
//			you want trace messages to always appear.	
KTrace t("RegSample");			//用于在DriverMonitor上输出调试信息

UNICODE_STRING SampleRegistryPath; 		//用于保存注册表路径

/////////////////////////////////////////////////////////////////////
// Begin INIT section
#pragma code_seg("INIT")

DECLARE_DRIVER_CLASS(RegSample, NULL)
/////////////////////////////////////////////////////////////////////
//  RegSample::DriverEntry
//
//	Routine Description:
//		This is the first entry point called by the system when the
//		driver is loaded.
// 
//	Parameters:
//		RegistryPath - String used to find driver parameters in the
//			registry.  To locate RegSample look for:
//			HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RegSample
//
//	Return Value:
//		NTSTATUS - Return STATUS_SUCCESS if no errors are encountered.
//			Any other indicates to the system that an error has occured.
//
//	Comments:
//

NTSTATUS RegSample::DriverEntry(PUNICODE_STRING RegistryPath)
{
	SampleRegistryPath.MaximumLength = RegistryPath->MaximumLength;
	//Unicode串（见第6章），最大可存储的字符串长度，与RegistryPath的相同
	SampleRegistryPath.Length = 0;	//当前有用的信息字符串长度
	SampleRegistryPath.Buffer = (PWSTR)ExAllocatePool( PagedPool, SampleRegistryPath.MaximumLength);
	//分配Unicode串存储缓冲区

	if( SampleRegistryPath.Buffer==NULL) return STATUS_INSUFFICIENT_RESOURCES;
	RtlCopyUnicodeString(&SampleRegistryPath,RegistryPath);
	//将RegistryPath串内容拷贝到SampleRegistryPath中
	KRegistryKey Params(RegistryPath, L"Parameters");//注册表类实例构造函数
	t << "RegistryPath:" << RegistryPath << "\n";	//输出注册表路径
	if ( NT_SUCCESS(Params.LastError()) )
	{
		// Load driver data members from the registry
		LoadRegistryParameters(Params);	//调用加载注册表参数函数
	}
	m_Unit = 0;
	return STATUS_SUCCESS;
}


/////////////////////////////////////////////////////////////////////
//  RegSample::LoadRegistryParameters
//
//	Routine Description:
//		Load driver data members from the registry.
// 
//	Parameters:
//		Params - Open registry key pointing to "Parameters"
//
//	Return Value:
//		None
//			
//	Comments:
//		Member variables are updated with values read from registry.
//
//		The parameters are found as values under the "Parameters" key,	
//		HKLM\SYSTEM\CurrentControlSet\Services\RegSample\Parameters\...
//

void RegSample::LoadRegistryParameters(KRegistryKey &Params)
{	//加载注册表参数函数
	ULONG	RegLength;

	m_RegDword = 0x123456;
	Params.QueryValue(L"RegDword", &m_RegDword);//读注册表参数RegDword的值
	t << "RegDword:" << m_RegDword << "\n";		//输出RegDword的值

	m_RegString = L"WDM";
	RegLength = 0;
	Params.QueryValue(L"RegString", m_RegString, RegLength, NonPagedPool);
	//读注册表参数RegString的值，因是字符串，置RegLength=0，表示重新分配内存空间
	t << "RegString:" << m_RegString << "\n";	//输出RegString的值
	// Setting RegLength to 0 indicates a new block should be allocated.
	// TODO: If RegLength is returned > 0, a new block was allocated
	// and should be deleted when no longer needed.
	if (RegLength != 0)	delete m_RegString;		//必须添加这一条语句
	//RegLength != 0，表示重新分配了内存空间。不再用时，要释放所分配的内存空间，
	//自动生成时，少了这一条语句，应加上

	m_RegBoolean = TRUE;
	Params.QueryValue(L"RegBoolean", &m_RegBoolean); 
	//读注册表参数RegBoolean的值
	t << "RegBoolean:" << m_RegBoolean << "\n";	//输出RegBoolean的值
}
// End INIT section
/////////////////////////////////////////////////////////////////////
#pragma code_seg()

/////////////////////////////////////////////////////////////////////
//  RegSample::AddDevice
//
//	Routine Description:
//		Called when the system detects a device for which this
//		driver is responsible.
//
//	Parameters:
//		Pdo - Physical Device Object. This is a pointer to a system device
//			object that represents the physical device.
//
//	Return Value:
//		NTSTATUS - Success or failure code.
//
//	Comments:
//		This function creates the Functional Device Object, or FDO. The FDO
//		enables this driver to handle requests for the physical device. 
//
NTSTATUS RegSample::AddDevice(PDEVICE_OBJECT Pdo)
{

    // Create the device object. Note that we used a form of "placement" new,
	// that is a member operator of KDevice.  This form will use storage
	// allocated by the system in the device object's device to store our
	// class instance.
	RegSampleDevice * pDevice = new (
			NULL,
			FILE_DEVICE_UNKNOWN,
			NULL,
			0,
			DO_DIRECT_IO
				| DO_POWER_PAGABLE
			)
		RegSampleDevice(Pdo, m_Unit);

	if (pDevice == NULL)
	{
	    return STATUS_INSUFFICIENT_RESOURCES;
	}

	NTSTATUS status = pDevice->ConstructorStatus();

	if ( !NT_SUCCESS(status) )
	{
		delete pDevice;
	}
	else
	{
		m_Unit++;

		pDevice->ReportNewDevicePowerState(PowerDeviceD0);
	}

	return status;
}

///////////////////////////////////////////////////////////////////
// Unload
//
//
VOID RegSample::Unload(void)
{	//重载Unload例程
	t << "Unloading RegSample WDM driver\n";

	// TODO: implmenent driver specific unload operations here

	if( SampleRegistryPath.Buffer!=NULL)
		ExFreePool(SampleRegistryPath.Buffer);
	// 驱动程序卸载时，须释放在DriverEntry例程中分配的内存空间

	// call the base class handler
	KDriver::Unload();	//调用基类Unload()例程
}

// EOF