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1.\"
2.\" Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
3.\"
4.TH nvram 8 "October 28, 2003"
5.SH NAME
6nvram \- manipulate firmware NVRAM variables
7.SH SYNOPSIS
8.B nvram
9[
10.B -p
11] [
12.B -f
13.IR filename
14] [
15.B -d
16.IR name
17] [
18.B -c
19] [
20.IR name
21[=
22.IR value
23]] ...
24.SH DESCRIPTION
25The
26.I nvram
27command allows manipulation of firmware NVRAM variables. It
28can be used to get or set a variable. It can also be used to print
29all of the variables or set a list of variables from a file.
30Changes to NVRAM variables are only saved by clean restart or shutdown.
31.LP
32In principle,
33.IR name
34can be any string. In practice, not all strings will be accepted.
35New World machines can create new variables as desired. Some variables
36require administrator privilege to get or set.
37.LP
38The given
39.IR value
40must match the data type required for
41.IR name .
42Binary data can be set using the %xx notation, where xx is the hex
43value of the byte. The type for new variables is always binary
44data.
45.SH OPTIONS
46.\" ==========
47.TP
48.BI \-d " name"
49Deletes the named firmware variable.
50.\" ==========
51.TP
52.BI \-f " filename"
53Set firmware variables from a text file. The file must be a
54list of "name value" statements. The first space on each line
55is taken to be the separator between "name" and "value". If
56the last character of a line is \\, the value extends to the next line.
57.\" ==========
58.TP
59.B \-x
60Use XML format for reading and writing variables.
61This option must be used before the
62.B \-p
63or
64.B \-f
65options, since arguments are processed in order.
66.TP
67.B \-c
68Delete all of the firmware variables.
69.TP
70.B \-p
71Print all of the firmware variables.
72.SH EXAMPLES
73.LP
74.RS
75example% nvram boot-args="-s rd=*hd:10"
76.RE
77.LP
78Set the boot-args variable to "-s rd=*hd:10". This would specify
79single user mode with the root device in hard drive partition 10.
80.LP
81.RS
82example% nvram my-variable="String One%00String Two%00%00"
83.RE
84.LP
85Create a new variable, my-variable, containing a list of two
86C-strings that is terminated by a NUL.
87.LP
88.RS
89example% nvram -d my-variable
90.RE
91.LP
92Deletes the variable named my-variable.
93.PD