CTL_CODE (Compact 2013)

10/16/2014

This macro creates a unique system I/O control.

Syntax

#define CTL_CODE(      DeviceType, Function, Method, Access) (
  ((DeviceType) << 16) | ((Access) << 14) | ((Function) << 2) | (Method))

Parameters

• DeviceType
  Defines the type of device for the given IOCTL.

  This parameter can be no bigger than a WORD value.

  The values used by Microsoft are in the range 0-32767; the values 32768-65535 are reserved for use by OEMs and IHVs.

  The following device types are defined by the system:

  • FILE_DEVICE_BEEP
  • FILE_DEVICE_CD_ROM
  • FILE_DEVICE_CD_ROM_FILE_SYSTEM
  • FILE_DEVICE_CONTROLLER
  • FILE_DEVICE_DATALINK
  • FILE_DEVICE_DFS
  • FILE_DEVICE_DISK
  • FILE_DEVICE_DISK_FILE_SYSTEM
  • FILE_DEVICE_FILE_SYSTEM
  • FILE_DEVICE_INPORT_PORT
  • FILE_DEVICE_KEYBOARD
  • FILE_DEVICE_MAILSLOT
  • FILE_DEVICE_MIDI_IN
  • FILE_DEVICE_MIDI_OUT
  • FILE_DEVICE_MOUSE
  • FILE_DEVICE_MULTI_UNC_PROVIDER
  • FILE_DEVICE_NAMED_PIPE
  • FILE_DEVICE_NETWORK
  • FILE_DEVICE_NETWORK_BROWSER
  • FILE_DEVICE_NETWORK_FILE_SYSTEM
  • FILE_DEVICE_NULL
  • FILE_DEVICE_PARALLEL_PORT
  • FILE_DEVICE_PHYSICAL_NETCARD
  • FILE_DEVICE_PRINTER
  • FILE_DEVICE_SCANNER
  • FILE_DEVICE_SERIAL_MOUSE_PORT
  • FILE_DEVICE_SERIAL_PORT
  • FILE_DEVICE_SCREEN
  • FILE_DEVICE_SOUND
  • FILE_DEVICE_DEVICE_STREAMS
  • FILE_DEVICE_TAPE
  • FILE_DEVICE_TAPE_FILE_SYSTEM
  • FILE_DEVICE_TRANSPORT
  • FILE_DEVICE_UNKNOWN
  • FILE_DEVICE_VIDEO
  • FILE_DEVICE_VIRTUAL_DISK
  • FILE_DEVICE_WAVE_IN
  • FILE_DEVICE_WAVE_OUT
  • FILE_DEVICE_8042_PORT
  • FILE_DEVICE_NETWORK_REDIRECTOR
  • FILE_DEVICE_BATTERY
  • FILE_DEVICE_BUS_EXTENDER
  • FILE_DEVICE_MODEM
  • FILE_DEVICE_VDM
  • FILE_DEVICE_MASS_STORAGE
  • FILE_DEVICE_SMB
  • FILE_DEVICE_KS
  • FILE_DEVICE_CHANGER
  • FILE_DEVICE_SMARTCARD
  • FILE_DEVICE_ACPI
  • FILE_DEVICE_DVD
  • FILE_DEVICE_FULLSCREEN_VIDEO
  • FILE_DEVICE_DFS_FILE_SYSTEM
  • FILE_DEVICE_DFS_VOLUME
  • FILE_DEVICE_LIGHT

  The following device types are specific to Windows Embedded Compact:

  • FILE_DEVICE_HAL
  • FILE_DEVICE_CONSOLE
  • FILE_DEVICE_PSL
  • FILE_DEVICE_SERVICE

• Function
  Defines an action within the device category.

  Function codes 0-2047 are reserved; codes 2048-4095 are reserved for OEMs and IHVs.

  A function code can be no larger then 4095.

• Method
  Defines the method codes for how buffers are passed for I/O and file system controls.

  The following values are possible for this parameter:

  • METHOD_BUFFERED
  • METHOD_IN_DIRECT
  • METHOD_OUT_DIRECT
  • METHOD_NEITHER

  This field is ignored by Windows Embedded Compact. You should always use the METHOD_BUFFERED value unless compatibility with Windows-based desktop platforms is required using a different Method value.

• Access
  Defines the access check value for any access.

  The following table shows the possible flags for this parameter. The FILE_ANY_ACCESS is generally the correct value.

  Flag	Description
  FILE_ANY_ACCESS	Request all access.
  FILE_READ_ACCESS	Request read access. Can be used with FILE_WRITE_ACCESS.
  FILE_WRITE_ACCESS	Request write access. Can be used with FILE_READ_ACCESS.

Return Value

None.

Remarks

The macro can be used for defining I/O control and files system controls. All I/O controls must be defined this way to ensure that values used by Microsoft, OEMs, and IHVs do not overlap.

The following illustration shows the format of the resulting I/O control.

Requirements

See Also

Reference

OAL Macros