NVRAM resetting

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vid
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Tue Nov 02, 2010 1:38 pm

Hi, I have several problems and questions:

Long story short, I was experimenting and screwed-up my NVRAM settings. That means my board is currently unbootable, only thing that works is BIOS Restore (remove jumper and insert CD with .BIO file in root) and that doesn't help (as it probably doesn't delete NVRAM vars which caused my problem). I might be able to "workaround" this problem, but for future hacking of this sort, I'd like to have convenient way to restore NVRAM contents. As I am more from the software side, so I'd like if someone can give me short intro to practical accessing NVRAM "externally".

I remember that some of you guys here mentioned (unfortunately I can't find the thread again) that on some boards it is possible to remove NVRAM chip from board, and access (read/write/dump/restore) it from separate device (called "programmer"?). So, my questions are:

1. Is NVRAM on same chip as BIOS (eg. NVRAM writes are "flashing BIOS"), or is it separate chip? How to locate it on board?
2. How do I find if NVRAM chip can be removed from my board?
3. In case it can't, I'll probably purchase some board which gives me this option for futher experimentation (most likely Tiano-based board from Intel). How can I determine whether some specific board supports this, before purchasing it?
4. More info on the device ("programmer"?) to access NVRAM externally, please?
5. Or maybe is there any other way to reset NVRAM settings to something that works? (Yes, it will make installed UEFI-based operating systems unbootable, I don't have problem with that)

Any kind of help would be much appreciated, thanks in advance.
edwin
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Tue Nov 02, 2010 3:33 pm

.BIO file suggest we're dealing with an Intel board. What brand model is the board? What brand/model system is it from?
edwin/evasive

Do not assume anything

System error, strike any user to continue...
vid
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Wed Nov 03, 2010 9:49 am

Oh, I forgot :)

It's Intel DG33BU
edwin
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Wed Nov 03, 2010 5:46 pm

so you are using this file then:
http://downloadcenter.intel.com/Detail_ ... 0&lang=eng

and after using the recovery method you still get an NVRAM settings error? Because they are completely cleared in the recovery process. the only things i can think of: using incompatible memory. using an add-in card with incompatible bios. flat cmos battery (CR2032 coin cell). faulty keyboard. power supply problem.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
Denniss
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Thu Nov 04, 2010 12:31 pm

Please try the Bios restore with the Bios version that was installed on this board. Using a different/new version sometimes fails to fully recover a damaged Bios especially ifthe newer Bios had some changes in the Bootblock Bios.
edwin
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Thu Nov 04, 2010 3:29 pm

Maybe this is true for the newer bioses but I have never had problems using the Intel recovery procedure with the latest bios even if the board had a previous version...
edwin/evasive

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System error, strike any user to continue...
vid
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Mon Nov 22, 2010 9:38 am

Sorry for late reply, something seems to have gone wrong with automatic notification.

Yes, that's the file I am using. I use the method with removing jumper and inserting media (USB pen) with .BIO file in its root.

And no, BIOS Restore apparently doesn't restore UEFI NVRAM variables. That also makes sense, when you think about it. Doing so would render any installed UEFI-based OS unbootable (as its Boot#### and BootOrder variables would be destroyed). Now if users would do a BIOS restore, something they used to do on non-UEFI boards, and suddenly they can't boot their OS anymore, they'd probably be pretty pissed off.

There is also other way I can use to confirm it's the addition of NVRAM variable, that causes these problems. The BIOS Restore (last thing that is still working) only works when I physically disconnect the drive referred to by contents of NVRAM variable that I added. And these problems started right after adding the variable. So it is extremely unlikely for these problems to be caused by some HW failure or something else.

If there is no way to reset NVRAM "externally", I think I will just keep the board until I have analyzed enough of UEFI to hack up my own "BIOS update" which deletes this variable. Long-term project, for sure. :)
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