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A question for W1zzard.

Jan 11, 2012
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Hi, do you remember my thread? http://www.techpowerup.com/forums/showthread.php?t=158500

@W1zzard, in your post you mention that I should ask AMD on how to do I2C transfers. Could you be more specific on how I should contact AMD about this.
Their forums or an e-mail(if so, which one exactly)? The reason I did not do so back then, was because I failed at my attempts at I2C and was unfamiliar with writing drivers(still am, but I am more enthusiastic right now).
If you have any additional tips for I2C, those are welcome, too :toast:.

I know that Windows x64 based machines require signed drivers in order to be executed, but this should not be so for x86, right? And it's likely bypassable for debug/testing purposes.

I apologize if I am overstepping myself in my requests. However, anything related to I2C under Windows or GPU VRMs(or GPU sensor related stuff in general) is extremely scarce on the internet right now.
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Maybe start at developer.amd.com or pick up the phone and ask around at AMD. Really don't know. I seriously doubt you'll get any information from AMD though.

In the other thread you linked to some Linux sourcecode. Your best bet is to work with that.

Microsoft has lots of into on codesigning for drivers on their site, I think there is a way to bypass it on your developer machine
Jan 11, 2012
7 (0.00/day)
Just wanted to post back that I was able to do what I wanted. I can successfully obtain VRM temps.

It's thanks to the Linux source code that I was able to do it(albeit GPL'ed code). Took a while to figure out how to map memory to userspace, but I also did that thanks PhyMem on CodeProject.

It actually got me thinking, if I map physical memory to userspace, that means GPU-z does it as well, and isn't that an attack vector for anyone to arbitrarily map whatever he wants and thus take control the system?

Also, I am barely able to find information about Voltage controllers on AMD cards let alone how to access the I/O ports. I currently only have code for the VT1165 controller that works for 5850 and 5870. So, am I to understand you have signed an NDA with AMD and Nvidia to obtain datasheets and whatnot?