It can also be used to print all of the variables or set a list of variables from a file. In principle, name can be any string. In practice, not all strings will be accepted. Old world machines have a fixed set of Open Firmware variables. New World machines can create new varibles as desired.
Some variables require adminstrator privilege to get or set.
The given value must match the data type required for name . The type for new variables is always binary data. Instead set boot-args with the desired arguments. This would specifiy single user mode with the root device in hard drive partition 10.