You cannot install Open Firmware updates when the computer is started up from Mac OS X versions 10.0 to 10.1. Start up from Mac OS 9 to update firmware.
Note: Mac OS 9 is included with Mac OS X and should be installed on your computer's hard disk to perform this procedure.
You can follow these steps to start up the computer from Mac OS 9, and then go back to Mac OS X:
1. Choose System Preferences from the Apple menu.
2. Click Startup Disk.
3. Choose your Mac OS 9 System Folder.
4. Close System Preferences, completing a confirmation if prompted.
5. Choose Restart from the Apple menu.
6. Follow the instructions included with the firmware update.
7. Open the Startup Disk control panel.
8. Select the Mac OS X System Folder.
9. Choose Restart from the Special menu.