From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Tue, 23 Jul 2013 11:25:54 +0100
Subject: linux setup
In-Reply-To: <CANEcUBXMPhTjgVYbRN7NY+EUjh7DDGpKnZ8_LXY-ZLcfbH65Ug@mail.gmail.com>
References: <CANEcUBXMPhTjgVYbRN7NY+EUjh7DDGpKnZ8_LXY-ZLcfbH65Ug@mail.gmail.com>
Message-ID: <20130723102554.GD3748@MacBook-Pro.local>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Jul 22, 2013 at 02:28:50PM +0100, zhaobin xv wrote:
> I recently read lernel source .
> I have a question:In
> folder:linux/arch/arm/boot/compressed/head.S(linux2.6.22.6):
> 
> 
> start:
>         .type    start,#function
>         .rept    8
>         mov    r0, r0
>         .endr
> 
>         b    1f
>         .word    0x016f2818        @ Magic numbers to help the loader
>         .word    start            @ absolute load/run zImage address
>         .word    _edata            @ zImage end address
> 1:        mov    r7, r1            @ save architecture ID
>         mov    r8, r2            @ save atags pointer
> 
> 
> I don't kown why the ?mov r0 r0 ? repeated  emergence 8 times.

I think some people used that in the past to be able to modify the
zImage binary directly and work around wrong register values passed by
the boot loader. I've never used it myself but I saw it mentioned once.

-- 
Catalin