Hi Gurus,
Can somebody explain me actually how a NVRAM works on a sparc server. I am really confused and the same level of confusion with eeprom .
Think of PROM like the BIOS on x86 hardware. On SPARC hardware you manipulate those settings such as auto-boot and other options from PROM. You access it before the OS boots or by sending a break to the system. It's 100% command line driven unlike a BIOS. The eeprom tool inside Solaris allows you to view an manipulate NVRAM from the OS. Anything you change using the eeprom command won't take affect until the next reboot.
Do a man on eeprom and you'll see more detail.
Here is Wikipedia's arcticle on NVRAM:
Non-volatile random-access memory - Wikipedia, the free encyclopedia