Direct access to hadware

[M. Warner Losh]

In message: <9dd63e580603281516jee694b6sa7274b48c25f98c8 at mail.gmail.com>
            Eder <ederbsd at gmail.com> writes:
: Hi all,
: 
: I would like to know if exite some header ".h" in FreeBSD so
: that I can make a direct access to hadware in machine with C.
: 
: The intention is to make some things as, for example, to record ' FFFF ' in
: first
: the 512 bytes of hd or to record one floppy with ' FFFF ' of track zero.

create a file with all ffff's.  dd if=file of=/dev/ad0.

Warner