Re: [Xen-devel] loading IDT in xen?

To:	"Jun Koi" <junkoi2004@xxxxxxxxx>
Subject:	Re: [Xen-devel] loading IDT in xen?
From:	"余上" <yusunn@xxxxxxxxx>
Date:	Thu, 31 Jan 2008 14:56:23 +0800
Cc:	xen-devel@xxxxxxxxxxxxxxxxxxx
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There is another IDTR reload in x86_32.S at line 15 , where the
protected mode IDT vectors are initialized with ignore_int handler
firstly. Then trap_init called from __xen_start will setup the formal
IDT vectors .

2008/1/31, Jun Koi <junkoi2004@xxxxxxxxx>:
> 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
>

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