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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH] force stackpointer alignment in 64bit kernel
Date: Fri, 3 Mar 2006 20:29:40 +0100
To: Olaf Hering <olh@suse.de>
Cc: linuxppc-dev@ozlabs.org
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> The stackpointer came from 32bit code, which appearently has different
> alignment rules than 64bit code. The chain was yaboot -> zImage ->  
> vmlinux
> Force the stackpointer to be 16 byte aligned.

The stack pointer is required to be 16-byte aligned when the
client program is started, on 32-bit as well.

>  	/* Make sure we are running in 64 bits mode */
> +	addi	r1,r1,16
> +	rlwinm	r1,r1,0,0,28
>  	bl	.enable_64b_mode

Not addi +16, not -16, just no addi at all...


Segher