DRIVER_OBJECT与设备对象DEVICE_OBJECT的区别与联系

DRIVER_OBJECT是驱动程序在内核中的数据结构，每个驱动程序有唯一DRIVER_OBJECT，IO管理器使用驱动程序对象代表每个设备驱动程序

驱动程序描述了驱动程序的载入到内存什么地方，

驱动程序的大小和它的主要入口点（MajorFunction数组）；

驱动程序对象有一个DeviceObject域指向一个设备对象链表，每个设备对象代表一个设备。

typedef struct _DRIVER_OBJECT {
    CSHORT Type;
    CSHORT Size;

    //

    // The following links all of the devices created by a single driver

    // together on a list, and the Flags word provides an extensible flag

    // location for driver objects.

    //


    PDEVICE_OBJECT DeviceObject;
    ULONG Flags;

    //

    // The following section describes where the driver is loaded. The count

    // field is used to count the number of times the driver has had its

    // registered reinitialization routine invoked.

    //


    PVOID DriverStart;
    ULONG DriverSize;
    PVOID DriverSection;
    PDRIVER_EXTENSION DriverExtension;

    //

    // The driver name field is used by the error log thread

    // determine the name of the driver that an I/O request is/was bound.

    //


    UNICODE_STRING DriverName;

    //

    // The following section is for registry support. Thise is a pointer

    // to the path to the hardware information in the registry

    //


    PUNICODE_STRING HardwareDatabase;

    //

    // The following section contains the optional pointer to an array of

    // alternate entry points to a driver for "fast I/O" support. Fast I/O

    // is performed by invoking the driver routine directly with separate

    // parameters, rather than using the standard IRP call mechanism. Note

    // that these functions may only be used for synchronous I/O, and when

    // the file is cached.

    //


    PFAST_IO_DISPATCH FastIoDispatch;

    //

    // The following section describes the entry points to this particular

    // driver. Note that the major function dispatch table must be the last

    // field in the object so that it remains extensible.

    //


    PDRIVER_INITIALIZE DriverInit;
    PDRIVER_STARTIO DriverStartIo;
    PDRIVER_UNLOAD DriverUnload;
    PDRIVER_DISPATCH MajorFunction[IRP_MJ_MAXIMUM_FUNCTION + 1];

} DRIVER_OBJECT;
typedef struct _DRIVER_OBJECT *PDRIVER_OBJECT;

 

PDEVICE_OBJECT DeviceObject
Pointer to the device objects created by the driver. This member is automatically updated when the driver calls IoCreateDevice successfully. A driver can use this member and the NextDevice member of DEVICE_OBJECT to step through a list of all the device objects that the driver created.
PDRIVER_EXTENSION DriverExtension
Pointer to the driver extension. The only accessible member of the driver extension is DriverExtension->AddDevice, into which a driver's DriverEntry routine stores the driver's AddDevice routine.
PUNICODE_STRING HardwareDatabase
Pointer to the \Registry\Machine\Hardware path to the hardware configuration information in the registry.
PFAST_IO_DISPATCH FastIoDispatch
Pointer to a structure defining the driver’s fast I/O entry points. This member is used only by FSDs and network transport drivers.
PDRIVER_INITIALIZE DriverInit
The entry point for the DriverEntry routine, which is set up by the I/O Manager.
PDRIVER_STARTIO DriverStartIo
The entry point for the driver’s StartIo routine, if any, which is set by the DriverEntry routine when the driver initializes. If a driver has no StartIo routine, this member is NULL.
PDRIVER_UNLOAD DriverUnload
The entry point for the driver’s Unload routine, if any, which is set by the DriverEntry routine when the driver initializes. If a driver has no Unload routine, this member is NULL.
PDRIVER_DISPATCH MajorFunction[IRP_MJ_MAXIMUM_FUNCTION+1]
A dispatch table consisting of an array of entry points for the driver’s DispatchXxx routines. The array

DEVICE_OBJECT是物理设备或逻辑设备在内核中的数据结构，跟这个概念相关的有PDO和FDO；PDO对应于具体的硬件设备，每个硬件设备对应一个PDO，而一个PDO可以对应多个FDO；PDO和FDO都是DEVICE_OBJECT的实体；同一个设备驱动程序对象下的所有设备通过NextObject域连接成一个链表（即上述驱动程序设备对象的一个域）；AttachedDevice域是针对“早期”驱动的（Window NT4以前的版本，在以后的版本中也可以正常使用）；DriverObject域指向与该设备相关的驱动程序对象。