Accessing PCI Device IDs by using Software in Protected Mode

[idata]

Ahoy and welcome brothers.

Currently i am searching for a way to access the PCI Devices of my System by using the DIDs (MSI X58 Pro-E, Intel Xeon E5620)

I want to Access the Device Number 2, Function 2 @ Bus 0xFF

My goal is to modify the QPI Link Data Rate without using the BIOS but unfortunately the registers are write protected

[img]http://extreme.pcgameshardware.de/attachments/846001d1440412820-werte-pci-devices-anpassen-wie-mit-offset-umgehen-c1.png http://extreme.pcgameshardware.de/attachments/846001d1440412820-werte-pci-devices-anpassen-wie-mit-offset-umgehen-c1.png[/img]

I want to replace the conent of this register of QPI Link 1 by the red marked numbers but unfortunately there is some kind of write protection even if they are signed as "RW"

Is there any Lock Bit that prevents any updating of the QPI Link registers?

[img]http://extreme.pcgameshardware.de/attachments/846002d1440412820-werte-pci-devices-anpassen-wie-mit-offset-umgehen-unterschied.png http://extreme.pcgameshardware.de/attachments/846002d1440412820-werte-pci-devices-anpassen-wie-mit-offset-umgehen-unters…[/img]

Well.. disabling the MC_Channel Lock Bit Registers also didnt work

[Cesar_B_Intel · Accepted solution]

Hello FBDIMM

In this case I suggest contacting the motherboard manufacturer to confirm with them.

The motherboard should allow you to access and modify the QPI Link Data Rate from the BIOS. However, if you want to access and modify the QPI Link Data Rate I suggest contacting the motherboard manufacturer to confirm with them.

Additionally, you may try the latest version of RW utility* The latest version is v1.6.8.1. http://rweverything.com/download/ Download | RWEverything

This may mount the QPI Link 1 in R/W so you may edit the required bits.

Best regards,

Caesar B.