nvram(8) System Manager's Manual nvram(8)
nvram - manipulate Open Firmware NVRAM variables
nvram [ -p ] [ -f filename ] [ name ] [= value ] ...
The nvram command allows manipulation of Open Firmware NVRAM variables.
It can be used to get or set a variable. It can also be used to print
all of the variables or set a list of variables from a file. Changes
to NVRAM variables are only saved by clean restart or shutdown.
In principle, name can be any string. In practice, not all strings
will be accepted. New World machines can create new variables as
desired. Some variables require administrator privilege to get or set.
The given value must match the data type required for name. Binary
data can be set using the %xx notation, where xx is the hex value of
the byte. The type for new variables is always binary data.
-p Print all of the Open Firmware variables.
Set Open Firmware variables from a text file. The file must be
a list name=value statements. If the last character of a line
is \, the value will be continued to the next line.
example% nvram boot-args="-s rd=*hd:10"
Set the boot-args variable to "-s rd=*hd:10". This would specify sin-
gle user mode with the root device in hard drive partition 10.
example% nvram my-variable="String One%00String Two%00%00"
Create a new variable, my-variable, containing a list of two C-strings
that is terminated by a NUL.
December 12, 2000 nvram(8)