1 .\" Hey Emacs! This file is -*- nroff -*- source.
3 .\" Copyright (c) 1993 Michael Haardt
5 .\" Fri Apr 2 11:32:09 MET DST 1993
7 .\" This is free documentation; you can redistribute it and/or
8 .\" modify it under the terms of the GNU General Public License as
9 .\" published by the Free Software Foundation; either version 2 of
10 .\" the License, or (at your option) any later version.
12 .\" The GNU General Public License's references to "object code"
13 .\" and "executables" are to be interpreted as the output of any
14 .\" document formatting or typesetting system, including
15 .\" intermediate and printed output.
17 .\" This manual is distributed in the hope that it will be useful,
18 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
19 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 .\" GNU General Public License for more details.
22 .\" You should have received a copy of the GNU General Public
23 .\" License along with this manual; if not, write to the Free
24 .\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
27 .\" Modified Sat Jul 24 15:12:05 1993 by Rik Faith <faith@cs.unc.edu>
28 .\" Modified Tue Aug 1 16:27 1995 by Jochen Karrer
29 .\" <cip307@cip.physik.uni-wuerzburg.de>
30 .\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
31 .\" Modified Mon Feb 15 17:28:41 CET 1999 by Andries E. Brouwer <aeb@cwi.nl>
32 .\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com>
33 .\" Added notes on capability requirements
35 .TH IOPERM 2 2007-06-15 "Linux" "Linux Programmer's Manual"
37 ioperm \- set port input/output permissions
39 .B #include <unistd.h>
42 .B #include <sys/io.h>
45 .BI "int ioperm(unsigned long " from ", unsigned long " num ", int " turn_on );
48 sets the port access permission bits for the calling process for
49 \fInum\fP bytes starting from port address \fIfrom\fP to the value
51 If \fIturn_on\fP is nonzero, the calling process must be privileged
52 .RB ( CAP_SYS_RAWIO ).
54 .\" FIXME is the following ("Only the first 0x3ff I/O ports can be
55 .\" specified in this manner") still true? Looking at changes in
56 .\" include/asm-i386/processor.h between 2.4 and 2.6 suggests
57 .\" that the limit is different in 2.6.
58 Only the first 0x3ff I/O ports can be specified in this manner.
61 system call must be used.
63 Permissions are not inherited by the child created by
65 Permissions are preserved across
67 this is useful for giving port access permissions to unprivileged
70 This call is mostly for the i386 architecture.
71 On many other architectures it does not exist or will always
74 On success, zero is returned.
75 On error, \-1 is returned, and
87 (on PowerPC) This call is not supported.
90 .\" Could not allocate I/O bitmap.
94 The calling process has insufficient privilege.
97 is Linux-specific and should not be used in programs
98 intended to be portable.
100 Libc5 treats it as a system call and has a prototype in
102 Glibc1 does not have a prototype.
103 Glibc2 has a prototype both in
107 Avoid the latter, it is available on i386 only.