[Xen-devel] loading IDT in xen?

To:	"List: Xen Developers" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	[Xen-devel] loading IDT in xen?
From:	"Jun Koi" <junkoi2004@xxxxxxxxx>
Date:	Thu, 31 Jan 2008 12:46:05 +0900
Delivery-date:	Wed, 30 Jan 2008 19:46:46 -0800
Dkim-signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; bh=sLO9i7arkHovg16pX12gdm/f5FPv89uAFdwEqOZepbM=; b=XHSYmnqb8ytouw3K32UVciQXM8lO9xuKFAXr5p3Mz+q7rnQKf7Ugl86KZaNCXWkp+6VBbSFxpPQGup35i4yn5EI0Go7aB1lD2L3PCQySE8stqfnr2ApEkW1d/S6y3RaqOvDv0i5Kb13U5T9vg+mvzO08GF3Vb3ddrVc2nDBlJKU=
Domainkey-signature:	a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=qm/GeD1Qa3NGszVMklPIY8wyxESEuIZz3/HGEt4p1uYlvIsqlus9oZraKSzm62RFCdHvgk8UUsxk1+SLZXpLZNZqVm70qIRMQqrxGb3PNQAior3lQgryHzXy/4Q4l81Qv/ietwOlTGJqemoNm80DBNgDMYQ53MDAKybZHhARQvE=
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxx
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

I am looking at the hypervisor code to see how Xen setup the IDT. But
it seems that the code in protected mode reuses the real mode IDT?

In arch/x86/boot/trampoline.S we have at several places:

lidt bootsym(idt_48)

And idt_48 is defined as:

idt_48: .word 0,0,0 # base = limit = 0

And in nowhere we initialize idt_48, which means idt_48 reuses real
mode IDT table. However, real mode IDT table has different format than
protected mode IDT, so this doesnt look to work for me.

Definitely I miss something here. Anybody could enlighten me how IDT
setting in protected mode work?

Thanks,
Jun

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel