Jeff Butler
Guest
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Posted:
Thu Jan 20, 2005 5:14 pm Post subject:
How does LaGrande's off-switch work? |
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Intel has gone on record stating that LaGrande technology will be disabled
when a LaGrande-capable system is shipped unless the customer specifically
requests that it be enabled. My question is this: If LaGrande is disabled,
what is the mechanism by which the new secure instructions are prevented
from executing?
We might expect a well-behaved LaGrande-aware application or OS to perform
as follows:
Read the LaGrande on/off switch from the BIOS
If LaGrande is on then
SENTER
Do secure stuff
SEXIT
else
Do something that does not require LaGrande
However, what if the application or OS is not so well-behaved, and
unconditionally performs:
SENTER
Do secure stuff
SEXIT
without ever checking the flag? What happens, and why? Thanks in advance. |
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