WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Re: xen-kernel and EDD

To: Keir Fraser <keir@xxxxxxx>
Subject: Re: [Xen-devel] Re: xen-kernel and EDD
From: Lin-Bao Zhang <2004.zhang@xxxxxxxxx>
Date: Mon, 22 Aug 2011 11:45:21 +0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Sun, 21 Aug 2011 20:45:55 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=nUNVeRWWAcZQlBYX6WkTPjh0SrXi37MGvcFwBhUqNvI=; b=RsgHMiLub/82Czgwoi2QvClIhx4WSNIkb1bgh7WkudH0rqZmVMvGJO3s99j4iL/STO O9w3KNuMw8NsBqoAwMMIoqvASxskGFGNgd/B/N8MF9R1VTt1CE8PU2YvG4QlUiMQd2U4 rFBbcO6w9spsk3L/y+1qFURLM7093wystsNQY=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <CANuKeP=PRAtf_TeoFvQk0B_XeC5YOGHpTf2xjhUbE4K-zaGY5A@xxxxxxxxxxxxxx>
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <CANuKePnjCwAePneoAKxXu453naxYVwPTt0hVwtML9KzHBLvS4g@xxxxxxxxxxxxxx> <CA727251.1F62E%keir.xen@xxxxxxxxx> <CANuKePmurLWCEEJVzbQv2hSzccUiE-NHDkuVddgyRyXapb9Znw@xxxxxxxxxxxxxx> <CA72B048.30827%keir@xxxxxxx> <CANuKePmOd7h2qiG=8AmyXqza805sEeg-o6csHpTM5fE+XK-6pA@xxxxxxxxxxxxxx> <CANuKePm+UHOaVU2c5DbTL2qcRRCssU-PZHbT_2c-86YqSMHhpw@xxxxxxxxxxxxxx> <CA73E212.1F72B%keir.xen@xxxxxxxxx> <CANuKeP=PRAtf_TeoFvQk0B_XeC5YOGHpTf2xjhUbE4K-zaGY5A@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
I have replied to another subject "about __XEN_VIRT_START and
0x100000" ,because key discussing has moved there .
however, I sent a copy here , because ,here is the original discussion
about "EBDA corrupted".  sorry for my 2 emails .


> Stacks grow downwards/backwards in memory. The early_stack definition is
> immediately *before* the early_stack label.
>
>> b) what is function of ”   mov     $bootsym_phys(early_stack),%esp" ?
>> is this related with trampoline relocation ?
>
> The trampoline stack (early_stack) is now allocated within the trampoline
> code/data area, rather than being hard-coded at an address (e.g., 0x98000).
>
a) the Stack ,how to grow downwards ?
if device changed/added,the stack will grows much ?
what device or function code will use this stack ?
what time does this stack grow ?
Can this stack overwrite other things when grow downwards ? in
xen-4.1.0 , this stack top equals to trampoline_end ,will it overwrite
trampoline_code ?
I think maybe impossible ,because trampoline code has been moved to
BOOT_TRAMPOLINE .
why do I have such question ,please see my b)

b)
it seems that the core problem is the "early_stack" , in my case ,
Stack top is overlap P410i EBDA area when stack grows downwards,so
system can't boot again.
but But there is another question puzzled :
If 0x98000 value is wrong , we will think in any case , system will be
corrupted ,but if we disable or unplug FC card , system will boot
normally.
Very mystery.
Following is my guess:
I guess :    0x95400   ~   <------  0x98000 (stack top) ~  0xa0000
0x95400 … P410i_EBDA_start ….. P410i_EBDA_end …. 0x98000

We know stacks grow downwards/backwards in memory , so I guess P410i
EBDA area should be located in sub-area in 0x95400 ~0x98000.
I feel the stack size will change as device number.
Maybe ,if we plug FC card , the stack should be more larger ,
occasionally reach  P410i EBDA area. If unplug FC card , the stack
will be so small that it can’t reach P410i EBDA . who knows , maybe
only P410i firmware guys and FC card firmware guys , because only they
know their EBDA area range.
I will consult our firmware guys to verify my idea.

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