From: "H. Peter Anvin" <hpa@zytor.com>
To: Neil Horman <nhorman@redhat.com>
Cc: kexec@lists.infradead.org, ebiederm@xmission.com,
Neil Horman <nhorman@tuxdriver.com>
Subject: Re: Question regardin intel64 arch and page table setup
Date: Wed, 11 Aug 2010 18:53:13 -0700 [thread overview]
Message-ID: <4C635409.2060602@zytor.com> (raw)
In-Reply-To: <20100812010506.GB2258@localhost.localdomain>
On 08/11/2010 06:05 PM, Neil Horman wrote:
> Thanks for all the info, guys. I hadn't considered that we couldn't access the
> 64 bit startup point for the bzImage. I just figured we could jump to
> startup_32 + 0x200 in the bzImage header once I had the page table bit set up
> properly.
>
> I hadn't considered the problems we might encounter with driver issues loading
> above 4gb and what have you, nor the starting of AP's.
>
> Regardless, I'll keep tinkering. One more question. When setting up the page
> table in the panic boot case, is it sufficient to setup an identity map for the
> pages in the reserved crashkernel range, or do we need to identity map the
> entire range of ram?
>
> Best
> Neil
One thing... if the crashkernel reservation can be made non-contiguous,
it probably doesn't require a whole lot of memory below 1 MiB (a handful
of pages) and below 4 GiB (probably less than a megabyte) to achieve
full functionality. It just means that the crashkernel has to operate
with a true memory map for its reservations.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
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next prev parent reply other threads:[~2010-08-12 1:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-11 19:47 Question regardin intel64 arch and page table setup Neil Horman
2010-08-11 20:02 ` H. Peter Anvin
2010-08-11 21:51 ` Eric W. Biederman
2010-08-11 21:54 ` Eric W. Biederman
2010-08-11 22:02 ` H. Peter Anvin
2010-08-12 0:22 ` Eric W. Biederman
2010-08-12 1:05 ` Neil Horman
2010-08-12 1:46 ` H. Peter Anvin
2010-08-12 1:53 ` H. Peter Anvin [this message]
2010-08-12 3:21 ` Eric W. Biederman
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