Switching from long mode to compability mode.

flat assembler
Message board for the users of flat assembler.

Index > OS Construction > Switching from long mode to compability mode.

Author

Thread

Mac2004

Joined: 15 Dec 2003
Posts: 314

Mac2004

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: 3170
Location: Denmark

f0dder

a couple of pushes and iretd?

22 Jun 2007, 11:30

Mac2004

Joined: 15 Dec 2003
Posts: 314

Mac2004

f0dder: Thanx for the idea. Smile

I have to test it.

regards,
Mac2004

22 Jun 2007, 13:11

< Last Thread | Next Thread >

Forum Rules:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum