long mode GDT reload

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gerryg400
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Re: long mode GDT reload

Post by gerryg400 »

Found a couple of vague references to this on various websites. Seems that Intel supports the 16:64 indirect jump and AMD does not.

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gerryg400
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Re: long mode GDT reload

Post by gerryg400 »

I never reload the GDT following that. At no point do I need to reload CS except for when I do my initial entry to long mode.
Owen, don't you need to reload cs to get to ring 3 to run user mode code ?

Btw, I agree with StephanVanSchaik and use iret for this.

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Owen
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Re: long mode GDT reload

Post by Owen »

gerryg400 wrote:
I never reload the GDT following that. At no point do I need to reload CS except for when I do my initial entry to long mode.
Owen, don't you need to reload cs to get to ring 3 to run user mode code ?

Btw, I agree with StephanVanSchaik and use iret for this.

- gerryg400
Sure, but thats done implicitly in the iret or sysret, rather than by a direct jump. I mean the kernel CS.
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