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From: Wolfgang Denk <wd@denx.de>
To: nreddy@netenrich.com
Cc: u-boot-users@lists.sourceforge.net, linuxppc-embedded@ozlabs.org
Subject: Re: "How to change the Magic number"
Date: Mon, 22 May 2006 15:00:30 +0200	[thread overview]
Message-ID: <20060522130030.B45D23525D9@atlas.denx.de> (raw)
In-Reply-To: Your message of "Mon, 22 May 2006 05:21:01 PDT." <45530.61.95.208.2.1148300461.squirrel@61.95.208.2>

In message <45530.61.95.208.2.1148300461.squirrel@61.95.208.2> you wrote:
> 
>  I have a specific requirement to change the Magic number of the linux
> kernel in my embedded system.

You are off track.

>  I cound see the Magic number is defined in U-boot files:
>  1.include/image.h:#define IH_MAGIC        0x27051956
>  2.cpu/ppc4xx/start.S:     .long   0x27051956

This magic number is only used by U-Boot, and  ther  e  only  in  the
image header. It has no relevance in any way to the LInu xkernel.

>   So i can modify in u-boot to make it compatible to my Kernel (i am using
> montavista linux version 2.4.20), but i am not able to see this kindof
> info anywhere in the kernel source files.

You are looking at the wrong place. This magic number is not used  or
accessed anywhere in the Linu xkernel.

> If anyone knows how the linux magic number is generated and what are the
> files
>  need modifications inorder to change magic number please let me know.

Linux itself has no such magic number. Especially not on PPC.

[But if you find a way to change  that  magic  number,  I  would  not
protest  if  you  added 10 or 20 to the last 4 digits. Just make sure
the change is propagated back to it's origin. :-) ]

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
The easiest way to figure the cost of living is to take  your  income
and add ten percent.

      reply	other threads:[~2006-05-22 13:00 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-22 12:21 "How to change the Magic number" nreddy
2006-05-22 13:00 ` Wolfgang Denk [this message]

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