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Date: Fri, 04 May 2007 11:25:48 -0700
From: Jeremy Fitzhardinge <jeremy@goop.org>
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To: "Eric W. Biederman" <ebiederm@xmission.com>
CC: Rusty Russell <rusty@rustcorp.com.au>, Andi Kleen <ak@suse.de>,
       Chris Wright <chrisw@sous-sol.org>, Zachary Amsden <zach@vmware.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
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       lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 3/3] boot bzImages under paravirt
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Eric W. Biederman wrote:
>>> load the segments as well.
>>>
>>> Gujin looks like it loads just %es and %ds.
>>>   
>>>       
>> We should be able to make do with that until we've got our own gdt.
>>     
>
> Right after the segments loads we have:
> 	leal 0x40(%esi), %esp
> 	call 1f
> 1:	popl %ebp
> 	subl $1b, %ebp
>
> That uses %ss and %ds.  Can we use a segment override on a call
> instruction?
>   

I overlooked Gujin missing %ss.  That's harsh.  Easy for them to fix,
presumably.

> Yes.  Exactly like we do for real mode code, and with exactly the same
> values.  Just in a little different format.

Well, fits in well with Xen's requirements, since it wants ELF notes
there for exactly the same reason.

    J