linux-mips
[Top] [All Lists]

Re: memory for exception vectors

To: Jun Sun <jsun@mvista.com>
Subject: Re: memory for exception vectors
From: Ladislav Michl <ladis@linux-mips.org>
Date: Tue, 13 May 2003 18:11:52 +0100
Cc: linux-mips@linux-mips.org
In-reply-to: <20030513095244.B26990@mvista.com>; from jsun@mvista.com on Tue, May 13, 2003 at 09:52:44AM -0700
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20030512115641.F17151@ftp.linux-mips.org> <20030512104408.C24045@mvista.com> <20030513105145.D22288@ftp.linux-mips.org> <20030513095244.B26990@mvista.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.2.5.1i
On Tue, May 13, 2003 at 09:52:44AM -0700, Jun Sun wrote:
[snip]
> I figured that out a while back.  I think you can find answers in
> arch/mips/kernel/setup.c, 
> 
>       start_pfn = PFN_UP(__pa(&_end));

Strange I read that file many times, but for yet unknown reason never noticed
__pa(&_end). That's what I call selective blindness :)

> I think zero pages are allocated so that all future read-only zero-filled
> pages can be mapped to them.  They are allocated at the beginning of
> start_pfn, which is also after kernel image.

Thanks a lot for explanation, now I'm sure that MC based memory probing for
IP22 will not break anything. Patch will come tomorrow.

        Ladis

<Prev in Thread] Current Thread [Next in Thread>