1.\" $OpenBSD: bio.4,v 1.4 2003/03/14 10:07:35 jmc Exp $ 2.\" 3.\" Copyright (c) 2002 Niklas Hallqvist 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. The name of the author may not be used to endorse or promote products 15.\" derived from this software without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 21.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 25.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 26.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27.\" POSSIBILITY OF SUCH DAMAGE. 28.\" 29.Dd June 8, 2002 30.Dt BIO 4 31.Os 32.Sh NAME 33.Nm bio 34.Nd ioctl tunnel pseudo-device 35.Sh SYNOPSIS 36.Nm pseudo-device bio 37.Op Ar count 38.Sh DESCRIPTION 39The 40.Nm 41driver provides userland applications ioctl access to devices otherwise not 42found as 43.Pa /dev 44nodes. 45The 46.Pa /dev/bio 47device node operates by delegating 48.Xr ioctl 2 49calls to a requested device driver. 50Only drivers which have registered with the 51.Nm 52device can be accessed via this interface. 53.Pp 54If 55.Ar count 56is given in the specification, and is greater than 0, a maximum of one 57.Nm bio 58device is created. 59.Pp 60The following 61.Xr ioctl 2 62calls apply to the 63.Nm bio 64device: 65.Bl -tag -width BIOCLOCATE 66.It Dv BIOCLOCATE 67Locate a named device and give back a cookie to the application 68for subsequent ioctl calls. 69The cookie is used to tunnel further ioctls to the right device. 70.El 71.Sh FILES 72.Bl -tag -width /dev/bio -compact 73.It Pa /dev/bio 74ioctl tunnel device 75.El 76.Sh SEE ALSO 77.Xr gdt 4 78.Sh HISTORY 79The 80.Nm 81driver appeared in 82.Ox 3.2 . 83