FIX: Problem with GENPORT.C: PortAddress Not Initialized

The information in this article applies to:

• Microsoft Win32 Device Development Kit (DDK) for Windows NT version 3.5

SYMPTOMS

PORTIO is a code sample for a generic port I/O driver. The sample driver (GENPORT.SYS), which is part of the PORTIO sample, is found on the Windows NT DDK CD in \Q_A\SAMPLES\DDK\PORTIO.

There is a problem with this version of the sample in that it does not claim the correct I/O ports during the call to IoReportResourceUsage.

CAUSE

The variable, PortAddress, is not initialized.

RESOLUTION

You can obtain a corrected version of PORTIO sample from the Microsoft Software Library, from the July 1995 MSDN CD, or you can fix it yourself as instructed below.

Downloading a New Copy

Download PORTIO.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:

• Microsoft Download Service (MSDL)

        Dial (206) 936-6735 to connect to MSDL
        Download PORTIO.EXE (size: 29133 bytes) 
  

• Internet (anonymous FTP)

        ftp ftp.microsoft.com
        Change to the SOFTLIB\MSLFILES directory
        Get PORTIO.EXE (size: 29133 bytes) 
  

Fix It Yourself

Instead of downloading it, you can fix it yourself by adding two lines to DriverEntry.

Change this:

               PortBase = DefaultBase;
               PortCount = DefaultCount;
           }
           ExFreePool(paramPath.Buffer);
       }
   }

   // Register resource usage (ports)
   //
   // This ensures that there isn't a conflict between this driver and
   // a previously loaded one or a future loaded one.

               PortBase = DefaultBase;
               PortCount = DefaultCount;
           }
           ExFreePool(paramPath.Buffer);
       }
   }

   PortAddress.LowPart  = PortBase;
   PortAddress.HighPart = 0;

   // Register resource usage (ports)
   //
   // This ensures that there isn't a conflict between this driver and
   // a previously loaded one or a future loaded one.

STATUS

The PORTIO sample is corrected in the July 1995 MSDN.