public.h

This the second tutorial of the Writing Device Drivers series. There seems to be a lot of interest i

/**********************************************************************
 * 
 *  Toby Opferman
 *
 *  Driver Example
 *
 *  This example is for educational purposes only.  I license this source
 *  out for use in learning how to write a device driver.
 *
 *     Driver Public Header File
 **********************************************************************/




#ifndef __PUBLIC_H__
#define __PUBLIC_H__


/* 
 *   IOCTL's are defined by the following bit layout.
 *   [ Common | Device Type | Required Access | Custom | Function Code | Transfer Type ]
 *      31     30         16 15             14    13    12           2  1            0
 * 
 *   Common          - 1 bit.  This is set for user-defined device types.
 *   Device Type     - This is the type of device the IOCTL belongs to.  This can be user defined (Common bit set).  This must match the device type of the device object.
 *   Required Access - FILE_READ_DATA, FILE_WRITE_DATA, etc.  This is the required access for the device.
 *   Custom          - 1 bit.  This is set for user-defined IOCTL's.  This is used in the same manner as "WM_USER".
 *   Function Code   - This is the function code that the system or the user defined (custom bit set)
 *   Transfer Type   - METHOD_IN_DIRECT, METHOD_OUT_DIRECT, METHOD_NEITHER, METHOD_BUFFERED, This the data transfer method to be used.
 *
 */
#define IOCTL_EXAMPLE_SAMPLE_DIRECT_IN_IO    CTL_CODE(FILE_DEVICE_UNKNOWN, 0x800, METHOD_IN_DIRECT, FILE_READ_DATA | FILE_WRITE_DATA) 
#define IOCTL_EXAMPLE_SAMPLE_DIRECT_OUT_IO   CTL_CODE(FILE_DEVICE_UNKNOWN, 0x801, METHOD_OUT_DIRECT,FILE_READ_DATA | FILE_WRITE_DATA) 
#define IOCTL_EXAMPLE_SAMPLE_BUFFERED_IO     CTL_CODE(FILE_DEVICE_UNKNOWN, 0x802, METHOD_BUFFERED, FILE_READ_DATA | FILE_WRITE_DATA)
#define IOCTL_EXAMPLE_SAMPLE_NEITHER_IO      CTL_CODE(FILE_DEVICE_UNKNOWN, 0x803, METHOD_NEITHER,FILE_READ_DATA | FILE_WRITE_DATA) 

                               

#endif