nvram [ -p] [-f
Modifies Open Firmware variables, which control the boot-time behavior of your Macintosh. To list all Open Firmware variables, use nvram -p. The Apple Open Firmware page is http://bananajr6000.apple.com.
To change a variable, you must run nvram as root or as the superuser. To set a variable, use
value. For example, to configure Mac OS X to boot verbosely, use nvram boot-args=-v. (Booting into Mac OS 9 or earlier resets this.) The table in this section lists Open Firmware variables. Some variables use the Open Firmware Device Tree notation (see the TechNotes available at the Apple Open Firmware page).
Be careful changing the nvram utility, since incorrect settings can turn a G4 iMac into a $2,000 doorstop. If you render your computer unbootable, you can reset Open Firmware by zapping the PRAM. To zap the PRAM, hold down Option--P-R as you start the computer, and then release the keys when you hear a second startup chime.
Read the variables to be set from
filename, a text file of
Deletes Open Firmware variable
Display all Open Firmware variables.
Table 2-5. Open Firmware variables
The automatic boot settings. If