IoCreateDevice()

AddDevice 가 호출되면 PDO를 이용해 FDO를 생성한다.

IoCreateDevice()의 원형이다.

NTSTATUS 
  IoCreateDevice(
    IN PDRIVER_OBJECT  DriverObject,
    IN ULONG  DeviceExtensionSize,
    IN PUNICODE_STRING  DeviceName  OPTIONAL,
    IN DEVICE_TYPE  DeviceType,
    IN ULONG  DeviceCharacteristics,
    IN BOOLEAN  Exclusive,
    OUT PDEVICE_OBJECT  *DeviceObject
    );

인자들을 설명해보면.

1. DriverObject : AddDevice 인자로 받은 DriverObject를 그대로 넣어준다.

2. DeviceExtensionSize : DEVICE_EXTENSION의 크기를 넣어준다. sizeof(DEVICE_EXTENSION)

3. DeviceName : Device 이름이며 유니코드 형식을 지원한다. NULL 이면 이름을 제공하지 않겠다는 것이다.

4. DeviceType : 보통 드라이버를 공부하거나 개발 할 때 FILE_DEVICE_UNKNOWN 으로 놓는다. 

#define FILE_DEVICE_8042_PORT           0x00000027
#define FILE_DEVICE_ACPI                0x00000032
#define FILE_DEVICE_BATTERY             0x00000029
#define FILE_DEVICE_BEEP                0x00000001
#define FILE_DEVICE_BUS_EXTENDER        0x0000002a
#define FILE_DEVICE_CD_ROM              0x00000002
#define FILE_DEVICE_CD_ROM_FILE_SYSTEM  0x00000003
#define FILE_DEVICE_CHANGER             0x00000030
#define FILE_DEVICE_CONTROLLER          0x00000004
#define FILE_DEVICE_DATALINK            0x00000005
#define FILE_DEVICE_DFS                 0x00000006
#define FILE_DEVICE_DFS_FILE_SYSTEM     0x00000035
#define FILE_DEVICE_DFS_VOLUME          0x00000036
#define FILE_DEVICE_DISK                0x00000007
#define FILE_DEVICE_DISK_FILE_SYSTEM    0x00000008
#define FILE_DEVICE_DVD                 0x00000033
#define FILE_DEVICE_FILE_SYSTEM         0x00000009
#define FILE_DEVICE_FIPS                0x0000003a
#define FILE_DEVICE_FULLSCREEN_VIDEO    0x00000034
#define FILE_DEVICE_INPORT_PORT         0x0000000a
#define FILE_DEVICE_KEYBOARD            0x0000000b
#define FILE_DEVICE_KS                  0x0000002f
#define FILE_DEVICE_KSEC                0x00000039
#define FILE_DEVICE_MAILSLOT            0x0000000c
#define FILE_DEVICE_MASS_STORAGE        0x0000002d
#define FILE_DEVICE_MIDI_IN             0x0000000d
#define FILE_DEVICE_MIDI_OUT            0x0000000e
#define FILE_DEVICE_MODEM               0x0000002b
#define FILE_DEVICE_MOUSE               0x0000000f
#define FILE_DEVICE_MULTI_UNC_PROVIDER  0x00000010
#define FILE_DEVICE_NAMED_PIPE          0x00000011
#define FILE_DEVICE_NETWORK             0x00000012
#define FILE_DEVICE_NETWORK_BROWSER     0x00000013
#define FILE_DEVICE_NETWORK_FILE_SYSTEM 0x00000014
#define FILE_DEVICE_NETWORK_REDIRECTOR  0x00000028
#define FILE_DEVICE_NULL                0x00000015
#define FILE_DEVICE_PARALLEL_PORT       0x00000016
#define FILE_DEVICE_PHYSICAL_NETCARD    0x00000017
#define FILE_DEVICE_PRINTER             0x00000018
#define FILE_DEVICE_SCANNER             0x00000019
#define FILE_DEVICE_SCREEN              0x0000001c
#define FILE_DEVICE_SERENUM             0x00000037
#define FILE_DEVICE_SERIAL_MOUSE_PORT   0x0000001a
#define FILE_DEVICE_SERIAL_PORT         0x0000001b
#define FILE_DEVICE_SMARTCARD           0x00000031
#define FILE_DEVICE_SMB                 0x0000002e
#define FILE_DEVICE_SOUND               0x0000001d
#define FILE_DEVICE_STREAMS             0x0000001e
#define FILE_DEVICE_TAPE                0x0000001f
#define FILE_DEVICE_TAPE_FILE_SYSTEM    0x00000020
#define FILE_DEVICE_TERMSRV             0x00000038
#define FILE_DEVICE_TRANSPORT           0x00000021
#define FILE_DEVICE_UNKNOWN             0x00000022
#define FILE_DEVICE_VDM                 0x0000002c
#define FILE_DEVICE_VIDEO               0x00000023
#define FILE_DEVICE_VIRTUAL_DISK        0x00000024
#define FILE_DEVICE_WAVE_IN             0x00000025
#define FILE_DEVICE_WAVE_OUT            0x00000026

5. DeviceCharacteristics : 디바이스 속성을 결정한다. 해당사항이 없으면 0으로 설정한다.

Specifies one or more system-defined constants, combined with a bitwise OR operation, that provide additional information about the driver's device. These constants include the following:

FILE_AUTOGENERATED_DEVICE_NAME

Directs the I/O manager to generate a name for the device, instead of the caller specifying a DeviceName when it calls this routine. The I/O manager makes sure that the name is unique. This characteristic is typically specified by a PnP bus driver to generate a name for a physical device object (PDO) for a child device on the same bus. This characteristic is new starting with Microsoft Windows 2000 and Microsoft Windows 98.

FILE_CHARACTERISTIC_PNP_DEVICE

Indicates that the device object is part of a Plug and Play (PnP) stack. This characteristic is required if a bus driver (or bus filter driver) registers WMI support for a device object that has not yet received the IRP_MN_START_DEVICE request. FILE_CHARACTERISTIC_PNP_DEVICE is also required if a function or filter driver registers for WMI before attaching to its device stack.

FILE_CHARACTERISTIC_TS_DEVICE

Indicates that the device object is part of a Terminal Services device stack. Drivers should not set this characteristic.

FILE_CHARACTERISTIC_WEBDAV_DEVICE

Indicates that a Web-based Distributed Authoring and Versioning (WebDAV) file system is mounted on the device. Drivers should not set this characteristic.

FILE_DEVICE_IS_MOUNTED

Indicates that a file system is mounted on the device. Drivers should not set this characteristic.

FILE_DEVICE_SECURE_OPEN

(Microsoft Windows NT 4.0 with Service Pack 5 (SP5) and later versions of Windows)

Directs the I/O manager to apply the security descriptor of the device object to relative opens and trailing file name opens for the device. For more information, see the Controlling Device Namespace Access topic.

FILE_FLOPPY_DISKETTE

Indicates that the device is a floppy disk device.

FILE_READ_ONLY_DEVICE

Indicates that the device cannot be written to.

FILE_REMOTE_DEVICE

Indicates that the device is remote.

FILE_REMOVABLE_MEDIA

Indicates that the storage device supports removable media. Notice that this characteristic indicates removable media, not a removable device. For example, drivers for JAZ drive devices should specify this characteristic, but drivers for PCMCIA flash disks should not.

FILE_VIRTUAL_VOLUME

Indicates that the volume is virtual. Drivers should not set this characteristic.

FILE_WRITE_ONCE_MEDIA

Indicates that the device supports write-once media. Drivers do not set this member directly.

6. Exclusive : FALSE (OEM 입출력인 경우에는 TRUE로 명시한다.)

7. *DeivceObject : 이 함수를 호출하기전에 선언한 fdo address를 넘겨준다.

*이름 생성과 관련된 예제

=> 3번과 5번 파라메터로 fdo의 이름을 생성 할 수 있는데 아래와 같이 3가지 경우로 나누어진다.

IoCreateDevice(pdo, sizeof(DEVICE_EXTENSION), NULL, FILE_DEVICE_UNKNOWN, 0, FALSE, fdo)

=> fdo는 이름을 가지지 않는다.

IoCreateDevice(pdo, sizeof(DEVICE_EXTENSION), &name, FILE_DEVICE_UNKNOWN, 0, FALSE, fdo)

=> fdo는 이름을 가지며 개발자가 알 수 있다.

IoCreateDevice(pdo, sizeof(DEVICE_EXTENSION), NULL, FILE_DEVICE_UNKNOWN, FILE_AUTOGENERATED_DEVICE_NAME, FALSE, fdo)

=> fdo는 이름을 가지며 개발자가 알 수 없다.

참고 : IT EXPERT 윈도우 디바이스 드라이버 (한빛미디어)