UNIX for Dummies Questions & Answers

Hi Gurus,


I am totally confused . I have some questions regarding OBP,EEPROMand NVRAM, BIOS.

What actually are these how do they function and interact on a Sparc based solaris system.

What is ok> ?

What is system Firmware ?

How does the system startup?

Trying to google but lost with no answers.


Thanks for your help in advance.

EEPROM is electrically erasable programmable read only memory. It is used on the sparc to store a little program that runs automatically when the system turns on. The name of the program is OBP. PC's work the same way, but on a PC, the name of the program is bios. When a program is stored in EEPROM it is called firmware. NVRAM is non-volatile random access memory. On the sparc it is used by OBP to store stuff like the boot paths. Typically, OBP will read the boot path, which points to some disk, and load the boot block (very first sector). The boot block is supposed to then boot the kernel.

On a PC you can interrupt the boot process and talk to the bios. On my PC, I must hit F12, then I see a menu presented by the bios. On a sparc, all you get is a command line interface when you talk to OBP. And OBP's prompt is often just "OK>".

Thanks so much
Perderabo It cleared most of my doubts.....Thanks a lot again.

---------- Post updated at 03:41 PM ---------- Previous update was at 10:45 AM ----------

SO Perderabo can I Infer this from your above statement. Firmware upgrade means upgrading the Open Boot Program .I mean the little piece of software in eeprom. And any changes I am making at ok> I am making them in Open boot program stored in the EEPROM.

In general, yes. However there are rare cases where you may be updating firmware other than the OBP.

No, ksh is software, but a softare update may not update ksh. As fpmurphy mentions there may be more than one firmware program. The V240 server on my desk right now has OBP and ALOM which are both firmware. This is why we should speak of an uptime to OBP or an update to ALOM. Terms like "software update" or "firmware update" don't really convey much information.

And OBP does not store stuff in EEPROM. When you make a change at the ok prompt you are actually changing the NVRAM. The nvram is a chip with a little battery built into the chip. When the battery dies, so does the data in the chip. OBP continues to live in EEPROM and with a lot of effort you can boot a box in this condition. To confuse the issue, Sun has a program which can be run as root called eeprom. eeprom displays the stuff in nvram. I would love to know why they called it "eeprom".

It's been a while since I updated OBP, but I remember that I have to pop the cover off and flip a switch to make EEPRPOM updatable. Then after the update I flipped it back. (Or maybe it was a jumper?) Anyway EEPROM is usually fixed in value.

When i run prtdiag -v on a server i see the following .

============================ FW Version ============================
Version
------------------------------------------------------------
System Firmware 6.7.11 2010/10/12 12:33

====================== System PROM revisions =======================
Version
------------------------------------------------------------
OBP 4.30.4.b 2010/07/09 13:48

FW version system firmware version and the other OBP version. What does the system FW version means here.

What kind of server? Post the output of uname -a.