BIO(4)                    OpenBSD Programmer's Manual                   BIO(4)

NAME
     bio - ioctl tunnel pseudo-device

SYNOPSIS
     pseudo-device bio [count]
     [count]

DESCRIPTION
     The bio driver provides userland applications ioctl access to devices
     otherwise not found as /dev nodes.  The /dev/bio device node operates by
     delegating ioctl(2) calls to a requested device driver.  Only drivers
     which have registered with the bio device can be accessed via this inter-
     face.

     If count is given in the specification, and is greater than 0, a maximum
     of one bio device is created.

     The following ioctl(2) calls apply to the bio device:

     BIOCLOCATE  Locate a named device and give back a cookie to the applica-
                 tion for subsequent ioctl calls.  The cookie is used to tun-
                 nel further ioctls to the right device.

FILES
     /dev/bio  ioctl tunnel device

SEE ALSO
     gdt(4)

HISTORY
     The bio driver appeared in OpenBSD 3.2.

OpenBSD 3.5                      June 8, 2002                                1
