mount system call for nullfs

[alfix86]

> > I would use "mount" system call
> >
> >   int mount(const char *type, const char *dir, int flags, void *data);
> >
> > to mount a nullfs, the problem is about *data;
> >
> > Where can I find docs? Example? Code?

I solved,
The *data [0] was in FreeBSD4:

struct null_args {
char    *target;    /* Target of loopback  */
};

but was deleted [1], so  I'll use nmount

[0] http://fxr.watson.org/fxr/source/miscfs/nullfs/null.h?v=FREEBSD4
[1] https://svnweb.freebsd.org/base/head/sys/fs/nullfs/null.h?r1=65467&r2=97186

-- 
alfix86 <alfix86 at gmail.com>