Switching from long mode to compability mode.

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Mac2004

Joined: 15 Dec 2003
Posts: 314

Mac2004 22 Jun 2007, 06:27

Hi!

AMD64 manual says that switching from long mode to compability mode requirea changing Long mode bit to zero from CS register.

Here's my question: How this changing can be done? The long mode does not allow selector:offset jumps. and as far as I know changing CS register usually needs some tricks to do. Direct writing is not allowed.

regards,
Mac2004

22 Jun 2007, 06:27

f0dder

Joined: 19 Feb 2004
Posts: 3175
Location: Denmark

f0dder 22 Jun 2007, 11:30

a couple of pushes and iretd?

22 Jun 2007, 11:30

Mac2004

Joined: 15 Dec 2003
Posts: 314

Mac2004 22 Jun 2007, 13:11

f0dder: Thanx for the idea. Smile

I have to test it.

regards,
Mac2004

22 Jun 2007, 13:11

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