1.\" Copyright (c) 2003 Netflix, Inc 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd September 29, 2016 28.Dt EFIVAR 8 29.Os 30.Sh NAME 31.Nm efivar 32.Nd UEFI environemnt variable interaction 33.Sh SYNOPSIS 34.Nm 35.Op Fl abdDHlLNpRtw 36.Op Fl n Ar name 37.Op Fl f Ar file 38.Op Fl -append 39.Op Fl -ascii 40.Op Fl -attributes 41.Op Fl -binary 42.Op Fl -delete 43.Op Fl -fromfile Ar file 44.Op Fl -guid 45.Op Fl -hex 46.Op Fl -list-guids 47.Op Fl -list 48.Op Fl -name Ar name 49.Op Fl -no-name 50.Op Fl -print 51.Op Fl -print-decimal 52.Op Fl -raw-guid 53.Op Fl -write 54.Ar name Ns Op = Ns Ar value 55.Sh DESCRIPTION 56This program manages 57.Dq Unified Extensible Firmware Interface 58.Pq UEFI 59environment variables. 60UEFI variables have three part: A namespace, a name and a value. 61The namespace is a GUID that's self assigned by the group defining the 62variables. 63The name is a Unicode name for the variable. 64The value is binary data. 65All Unicode data is presented to the user as UTF-8. 66.Pp 67The following options are available: 68.Bl -tag -width 20m 69.It Fl n Ar name Fl -name Ar name 70Specify the name of the variable to operate on. 71The 72.Ar name 73argument is the GUID of variable, followed by a dash, followed by the 74UEFI variable name. 75The GUID may be in numeric format, or may be one of the well known 76symbolic name (see 77.Fl -list-guids 78for a complete list). 79.It Fl f Ar file Fl -fromfile Ar file 80When writing or appending to a variable, take the data for the 81variable's value from 82.Ar file 83instead of from the command line. 84This flag implies 85.Fl -write 86unless the 87.Fl -append 88flag is given. 89This is not well understood and currently unimplemented. 90.It Fl a Fl -append 91Append the specified value to the UEFI variable rather than replacing 92it.p 93.It Fl t Ar attr Fl -attributes Ar attr 94Specify, in user hostile hexidecimal, the attributes for this 95variable. 96See section 7.2 (GetVariable subsection, Related Definitions) of the 97UEFI Specification for hex values to use. 98.It Fl A Fl -ascii 99Display the variable data as modified ascii: All printable characters 100are printed, while unprintable characters are rendered as a two-digit 101hexadecimal number preceeded by a % character. 102.It Fl b Fl -binary 103Display the variable data as binary data. 104Usually will be used with the 105.Fl N 106or 107.Fl -no-name 108flag. 109Useful in scripts. 110.It Fl D Fl -delete 111Delete the specified variable. 112May not be used with either the 113.Fl -write 114or the 115.Fl -append 116flags. 117No 118.Ar value 119may be specified. 120.It Fl g Fl -guid 121flag is specified, guids are converted to names if they are known (and 122show up in 123.Fl -list-guids ). 124.It Fl H Fl -hex 125List variable data as a hex dump. 126.It Fl L Fl -list-guids 127Lists the well known GUIDs. 128The names listed here may be used in place of the numeric GUID values. 129These names will replace the numeric GUID values unless 130.Fl -raw-guid 131flag is specified. 132.It Fl l Fl -list 133List all the variables. 134If the 135.Fl -print 136flag is also listed, their values will be displayed. 137.It Fl N Fl -no-name 138Do not display the variable name. 139.It Fl p Fl -print 140Print the value of the variable. 141.It Fl d Fl -print-decimal 142Treat the value of the variable as a number and print it as a 143decimal. 144This is currently unimplemented. 145.It Fl R Fl -raw-guid 146Do not substitute well known names for GUID numeric values in output. 147.It Fl w Fl -write 148Write (replace) the variable specified with the value specified. 149.It Ar name 150Display the 151.Ar name 152environment variable. 153.It Ar name Ns = Ns Ar value 154Set the specified 155.Ar name 156to 157.Ar value . 158This is not yet implemented. 159If the 160.Sh COMPATIBILITY 161The 162.Nm 163program is intended to be compatible (strict superset) with a progam 164of the same name included in the Red Hat libefivar package. 165.Sh SEE ALSO 166Appendix A of the UEFI specification has the format for GUIDs. 167All GUIDs 168.Dq Globally Unique Identifiers 169have the format described in RFC 4122. 170.El 171