Reason for x86 descriptor type priority over present?

Emulation of old PCs, PC hardware, or PC peripherals.

Reason for x86 descriptor type priority over present?

Postby superfury » 2019-8-12 @ 08:37

Why does the type check have priority over the present bit check? If it isn't present, then wouldn't the type be invalid anyways? Why does it throw #GP(selector) instead of #NP(selector) when both are the case?
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Re: Reason for x86 descriptor type priority over present?

Postby peterferrie » 2019-8-13 @ 20:55

I suppose that checking present first might trigger someone to try to bring it into memory before finding that it's not usable anyway.
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