Solved

Accessing BIOS NVRAM ?

Posted on 2006-07-13
7
881 Views
Last Modified: 2013-11-12
Does anyone know how to access BIOS NVRAM address space?
I believe it can be done in 'Ring 0' but I'm not sure how.
I want to be able to modify a few bytes using VB6 and TVicHW52 . I'm running WIN98se.

Any help greatly appreciated.
0
Comment
Question by:aztarac
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
7 Comments
 

Author Comment

by:aztarac
ID: 17155787
I looked at that thread before I posted my question.

The 'accepted answer' does state that the way to write is not known.

The following Microsoft link for Bios writers may offer some clues...but I dont understand it:

>Writing to CMOS NVRAM
>BIOS code should write to CMOS NVRAM by generating a system management interrupt (SMI). AML code can generate a SMI by writing a specific value to the SMI command port. AML code can pass the CMOS offset and value to be written through the NVRAM memory operation region. The BIOS SMI handles the writes to CMOS, and also updates the memory area pointed by the CMRM operation region to reflect the correct CMOS contents.

Full text:
http://www.microsoft.com/whdc/system/pnppwr/powermgmt/BIOSAML.mspx

I'm still hoping for a solution:(

0
 
LVL 9

Accepted Solution

by:
Rob_Jeffrey earned 250 total points
ID: 17156373
Right - missed that.  
Sorry - I simply skimmed over the body.

Unless you want to get into device driver (DDK) devekopment - it doesn't look easy.
The entire problem is - viruses.  Because some lousy people have written some pretty nasty things in the past there is a lot of hidden and proprietary information regarding the NVRAM these days.

What is it you are trying to do?  Perhaps we can come at it from another angle?
0
 
LVL 49

Assisted Solution

by:DanRollins
DanRollins earned 250 total points
ID: 17330346
You may be able to install a device drive that will allow access to I/O ports.  Here's one:
    http://www.driverlinx.com/DownLoad/DlPortIO.htm

This article appears to be on point:
    Pop Open a Privileged Set of APIs with Windows NT Kernel Mode Drivers
    http://www.microsoft.com/msj/0398/driver.aspx

But I agree with Rob_Jeffrey:  If you describe your ultimate goal, it might be possible to find a way to avoid this low-level grunging.  Whenever there is a legitimate need for standard programs to access low-level resources, there is often an more direct way to do it.  So what's on your mind?

-- Dan
0

Featured Post

Want Experts Exchange at your fingertips?

With Experts Exchange’s latest app release, you can now experience our most recent features, updates, and the same community interface while on-the-go. Download our latest app release at the Android or Apple stores today!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

What is Waterfall Model? Waterfall model is the classic Software Development Life Cycle method practiced in software development process. As the name "waterfall" describes, this development is flowing downwards steadily like waterfall, i.e., procee…
Introduction This article explores the design of a cache system that can improve the performance of a web site or web application.  The assumption is that the web site has many more “read” operations than “write” operations (this is commonly the ca…
Monitoring a network: how to monitor network services and why? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the philosophy behind service monitoring and why a handshake validation is critical in network monitoring. Software utilized …
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…

636 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question