Re: [patch 1/2] x86: head_64.S cleanup - use straight move to CR4register

From: H. Peter Anvin
Date: Tue May 13 2008 - 13:04:29 EST


Cyrill Gorcunov wrote:
There is no need for testing the values because we already know
what they should be. Just set them in straight way.

He isn't testing them, he's setting individual bits.

Either of these is pretty silly; the right way to do this is:

movl $(X86_CR4_PAE|X86_CR4_PGE), %eax
movq %rax, %cr4

A movl in 64-bit mode zero extends.

-hpa
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