pDriverObject->MajorFunction[IRP_MJ_CREATE] = KMOpenClose;
pDriverObject->MajorFunction[IRP_MJ_CLOSE] = KMOpenClose;
pDriverObject->MajorFunction[IRP_MJ_PNP] = KMPnp;
pDriverObject->MajorFunction[IRP_MJ_POWER] = KMPower;
pDriverObject->MajorFunction[IRP_MJ_READ] = KMRead;

return KMAddDevice(pDriverObject, puServiceRegPath);
}

VOID KMUnload(IN PDRIVER_OBJECT pDriverObject)
{
PDEVICE_OBJECT tmpDevice;
PMY_DEVICE_EXTENSION myDeviceExtension;

KdPrint(("The unload function is invoked!\n"));

tmpDevice = pDriverObject->DeviceObject;
while (tmpDevice) {
PDEVICE_OBJECT nextDevice;

KdPrint(("delete devobj: 0x%p.\n",tmpDevice));
myDeviceExtension = (PMY_DEVICE_EXTENSION)tmpDevice->DeviceExtension;
// 如果还有完成例程没有执行，则取消掉这个完成例程
if (myDeviceExtension->IslCompletion) {
myDeviceExtension->IslCompletion->CompletionRoutine = NULL;
// 只去掉与完成例程相关的几个标志位，栈内的其它标志位非常重要，不能去除
myDeviceExtension->IslCompletion->Control &= ~(SL_INVOKE_ON_SUCCESS | SL_INVOKE_ON_CANCEL | SL_INVOKE_ON_ERROR);
}
IoDetachDevice(myDeviceExtension->AttachedTo);
nextDevice = tmpDevice->NextDevice;
IoDeleteDevice(tmpDevice);
tmpDevice = nextDevice;
}
}

NTSTATUS KMUnHandleIrp(DEVICE_OBJECT *DeviceObject, IRP *Irp)
{

KdPrint(("Irp: %d\n", IoGetCurrentIrpStackLocation(Irp)->MajorFunction));

IoSkipCurrentIrpStackLocation(Irp);
return IoCallDriver(((PMY_DEVICE_EXTENSION)DeviceObject->DeviceExtension)->AttachedTo, Irp);
}

NTSTATUS KMOpenClose(DEVICE_OBJECT *DeviceObject, IRP *Irp)
{
KdPrint(("KMOpenClose.\n"));

Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);

return STATUS_SUCCESS;
}

NTSTATUS KMPnp(DEVICE_OBJECT *DeviceObject, IRP *Irp)
{
PIO_STACK_LOCATION pIo = IoGetCurrentIrpStackLocation(Irp);

KdPrint(("KMPnp.\n"));

switch (pIo->MinorFunction) {
default:
IoSkipCurrentIrpStackLocation(Irp);
IoCallDriver(((PMY_DEVICE_EXTENSION)DeviceObject->DeviceExtension)->AttachedTo, Irp);
break;
}

return STATUS_SUCCESS;
}

NTSTATUS KMPower(DEVICE_OBJECT *DeviceObject, IRP *Irp)
{
KdPrint(("KMPower.\n"));

IoSkipCurrentIrpStackLocation(Irp);
PoStartNextPowerIrp(Irp);
return PoCallDriver(((PMY_DEVICE_EXTENSION)DeviceObject->DeviceExtension)->AttachedTo, Irp);
}

NTSTATUS KMAddDevice(IN PDRIVER_OBJECT pDriverObject,IN PUNICODE_STRING puServiceRegPath)
{
UNICODE_STRING usObjectName;
PDRIVER_OBJECT KbdDriver;
NTSTATUS status;
PDEVICE_OBJECT tmpDevice, myDevice;
UNICODE_STRING usDeviceName;
WCHAR buff[64];
int index = 0;
PMY_DEVICE_EXTENSION DeviceExtension;

RtlInitUnicodeString(&usObjectName, L"\\Driver\\KbdClass");

status = ObReferenceObjectByName(&usObjectName,
OBJ_CASE_INSENSITIVE,
NULL,
0,
IoDriverObjectType,
KernelMode,
NULL,
(PVOID)&KbdDriver);
if (!NT_SUCCESS(status)) {
KdPrint(("Find the kbd class failed!\n"));
return status;
}