From mboxrd@z Thu Jan  1 00:00:00 1970
From: Albert ARIBAUD <albert.aribaud@free.fr>
Date: Fri, 12 Nov 2010 08:53:43 +0100
Subject: [U-Boot] [PATCH] arm: add 8-byte alignment for ABI compliance
	before board_init_f
In-Reply-To: <1289544835-24425-1-git-send-email-hs@denx.de>
References: <1289544835-24425-1-git-send-email-hs@denx.de>
Message-ID: <4CDCF287.8010805@free.fr>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

Le 12/11/2010 07:53, Heiko Schocher a ?crit :
> suggested from Daniel Hobi<daniel.hobi@schmid-telecom.ch>
>
> Tested on following boards:
> arm1136: qong
> armv7: omap3_beagle
> arm926ejs: magnesium, tx25
>
> Signed-off-by: Heiko Schocher<hs@denx.de>
> cc: Daniel Hobi<daniel.hobi@schmid-telecom.ch>
> cc: Albert ARIBAUD<albert.aribaud@free.fr>

I'm a bit uneasy about having the symbol unaligned and the aligning done 
by the code (and in different places):

>   	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
> +	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */

> -	gd = (gd_t *) (CONFIG_SYS_INIT_SP_ADDR);
> +	gd = (gd_t *) ((CONFIG_SYS_INIT_SP_ADDR)&  ~0x07);
>

There is always a risk that overhauls of the code, or new uses elsewhere 
in the code, forget about the alignment constraint and use the symbol 
straight away, which could cause all sorts of hard to debug issues.

Could we not align the symbol value itself so that the code simply uses 
the symbol?

Amicalement,
-- 
Albert.