From: "H. Peter Anvin" <hpa@zytor.com>
To: Rik van Riel <riel@redhat.com>
Cc: "Kristian Høgsberg" <krh@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] Use structs instead of hardcoded offsets in x86 boot decompressor.
Date: Fri, 23 May 2008 23:17:01 -0700 [thread overview]
Message-ID: <4837B2DD.908@zytor.com> (raw)
In-Reply-To: <20080523210744.52fe7fde@bree.surriel.com>
Rik van Riel wrote:
>
> People who wonder why these pointers never get initialized: they
> point to the zeropage, which of course lives at address zero.
>
> /* The so-called "zeropage" */
> struct boot_params {
> struct screen_info screen_info; /* 0x000 */
> struct apm_bios_info apm_bios_info; /* 0x040 */
> __u8 _pad2[12]; /* 0x054 */
> struct ist_info ist_info; /* 0x060 */
> ...
>
Uhm... except it doesn't live at address zero, at all.
It's called "zeropage" because we used to recycle it into
empty_zero_page, a long long time ago.
The bootparms structure is pointed to by %esi being passed from the
setup code to the decompressor to the kernel.
-hpa
next prev parent reply other threads:[~2008-05-24 6:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-23 21:59 [PATCH 1/2] Use structs instead of hardcoded offsets in x86 boot decompressor Kristian Høgsberg
2008-05-23 21:59 ` [PATCH 2/2] Only print "Decompressing Linux" etc when 'noisy' is passed Kristian Høgsberg
2008-05-23 22:42 ` Johannes Weiner
2008-05-24 9:25 ` Mikael Pettersson
2008-05-24 18:07 ` Diego Calleja
2008-05-24 1:07 ` [PATCH 1/2] Use structs instead of hardcoded offsets in x86 boot decompressor Rik van Riel
2008-05-24 6:17 ` H. Peter Anvin [this message]
2008-05-25 4:03 ` Rik van Riel
2008-05-25 4:06 ` H. Peter Anvin
2008-05-25 4:25 ` Kristian Høgsberg
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