NAME    [Toc]    [Back]

     i386_iopl - change the i386 I/O privilege level

SYNOPSIS    [Toc]    [Back]

     #include <sys/types.h>
     #include <machine/sysarch.h>

     int
     i386_iopl(int iopl);

DESCRIPTION    [Toc]    [Back]

     i386_iopl() sets the i386 I/O privilege level to  the  value
specified by
     iopl.  This call is restricted to the superuser.

     Note:  Code  using the i386_iopl() function must be compiled
using -li386.

RETURN VALUES    [Toc]    [Back]

     Upon successful completion, i386_iopl() returns  0.   Otherwise, a value of
     -1 is returned and the global variable errno is set to indicate the error.

ERRORS    [Toc]    [Back]

     i386_iopl() will fail if:

     [EPERM]   The caller was not the superuser.

SEE ALSO    [Toc]    [Back]

     i386_get_ioperm(2), i386_set_ioperm(2)

REFERENCES    [Toc]    [Back]

     Intel, i386 Microprocessor Programmer's Reference Manual.

WARNING    [Toc]    [Back]

     You can really hose your machine if  you  enable  user-level
I/O and write
     to hardware ports without care.

OpenBSD      3.6                         October     14,     1995