Looking for ioperm maintainer (was Re: ioperm() with ports above 0x3ff)

Corinna Vinschen corinna-cygwin@cygwin.com
Tue Feb 19 23:21:00 GMT 2008

On Feb 18 21:15, Andrew Dyer wrote:
> I am having problems using ioperm() to try and access a parallel printer port on
> a PCI card in my system running WinXP.  The port is mapped to I/O port address
> 0xDCD8.  I cannot access the port because the ioperm() driver has a check to
> limit I/O port accesses to < 0x400.
> from /usr/src/ioperm-0.4/driver/ioperm.c, lines 95-100
> 		/* test input buffer size and parameters */
> 		if ((io_stack->Parameters.DeviceIoControl.InputBufferLength < sizeof (struct
> ioperm_data))
> 			|| (!ioperm_data) || (ioperm_data->from + ioperm_data->num > 0x400))
> 		{
> 			Irp->IoStatus.Status = STATUS_INVALID_PARAMETER;
> 		} else {
> [...]
> I can't rebuild the driver as I don't have access to the DDK.  Can someone

The necessary ddk files are part of the w32api package in the Cygwin
distro.  You don't have to install the Microsoft DDK package.

> rebuild it with the check modified so I could test it?

The ioperm package has no maintainer anymore since 2006.  If anybody
feels that maintaining ioperm would be something they could consider as
a fun side job, just read http://cygwin.com/setup.html and follow the


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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