News
 

Bookmark and Share

(0) 

A hacker has discovered a special debugging mechanism within central processing units (CPUs) made by Advanced Micro Devices. The mode potentially allows to learn more about how exactly AMD's chips work, reverse engineer them and make further discoveries regarding their capabilities. It should be understood that that present all the assumptions regarding the mode are just theories.

According to a discovery made by hackes who names himself Czerno AMD processors (Athlon XP and better) have included firmware-based debugging features that expand greatly over standard, architecturally defined capabilities of x86. For some reason though, the manufacturer has been tightly secretive about these features; hint of their existence was gained by glancing at the list of undocumented machine specific registers (MSRs).

There are at least four new machine specific registers (MSR) that are involved in the expanded debug facilities. All those MSRs are "password" protected against casual access : read/write access (RDMSR/WRMSR) to the registers is granted only if EDI holds the correct password value (9C5A203A), otherwise, a GPF exception occurs. All these registers default/reset values are zero.

Potentially, those registers may do something with built-in self test of microprocessors. They may also be required to properly implement processor's microcode during development. Considering the fact that nobody knows what exactly has been found, consequences of the discovery are hard to imagine.

Tags: AMD, Athlon, Phenom, Sempron, duron

Discussion

Comments currently: 0

Add your Comment




Latest News

Monday, July 21, 2014

12:56 pm | Microsoft to Fire 18,000 Employees to Boost Efficiency. Microsoft to Perform Massive Job Cut Ever Following Acquisition of Nokia

Tuesday, July 15, 2014

6:11 am | Apple Teams Up with IBM to Make iPhone and iPad Ultimate Tools for Businesses and Enterprises. IBM to Sell Business-Optimized iPhone and iPad Devices

Monday, July 14, 2014

6:01 am | IBM to Invest $3 Billion In Research of Next-Gen Chips, Process Technologies. IBM to Fund Development of 7nm and Below Process Technologies, Help to Create Post-Silicon Future

5:58 am | Intel Postpones Launch of High-End “Broadwell-K” Processors to July – September, 2015. High-End Core i “Broadwell” Processors Scheduled to Arrive in Q3 2015

5:50 am | Intel Delays Introduction of Core M “Broadwell” Processors Further. Low-Power Broadwell Chips Due in Late 2014