Intel Q35 bug before being corrected in august 08

[flone_sa]

Hello,

I was wondering how intel corrected the bug presented by J.Rutkwoska at the black hat 08 conference.

They released a BIOS patch (http://security-center.intel.com/advisory.aspx?intelid=INTEL-SA-00017&languageid=en-fr) for the bug few weeks after the bug was spotted. The patched BIOS lock some internal registers of the DRAM controller (TOUUD, REMAP BASE, REMAP LIMIT, TOLUD at least) so it cannot be changed after initialization.

Do anyone know which flag is set to make those internal registers being in read-only mode ? The chipset documentation mention that something like "ME stolen memory lock" can help, but i cannot figure out what exactly it is. (ME = Management Engine ?)

Thank you in advance for your replies.

Fernand

[David_O_Intel1]

Hi Fernand,

I was told that the register is Intel reserved. Sorry not to be of more help.

David Ott

[flone_sa]

Quoting - David Ott (Intel)

Hi Fernand,

I was told that the register is Intel reserved. Sorry not to be of more help.

David Ott

Ok. Thanks for your help. I will keep on re-examining the intel docs, i may find the answer of my question with perseverance.

Fernand