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