unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (NetBSD-6.1.5)
Page:
Section:
Apropos / Subsearch:
optional field

I386_IOPL(2)              System Calls Manual (i386)              I386_IOPL(2)

NAME
     i386_iopl -- change the i386 I/O privilege level

LIBRARY
     i386 Architecture Library (libi386, -li386)

SYNOPSIS
     #include <&lt;sys/types.h>&gt;
     #include <&lt;machine/sysarch.h>&gt;

     int
     i386_iopl(int iopl);

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

RETURN VALUES
     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
     i386_iopl() will fail if:

     [EPERM]   The caller was not the super-user, or the operation was not
               permitted at the current security level.

REFERENCES
     i386 Microprocessor Programmer's Reference Manual, Intel

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

NetBSD 6.1.5                    April 12, 2004                    NetBSD 6.1.5