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From: Albert ARIBAUD <albert.aribaud@free.fr>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arm: add 8-byte alignment for ABI compliance before board_init_f
Date: Fri, 12 Nov 2010 08:53:43 +0100	[thread overview]
Message-ID: <4CDCF287.8010805@free.fr> (raw)
In-Reply-To: <1289544835-24425-1-git-send-email-hs@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.

  parent reply	other threads:[~2010-11-12  7:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-12  6:53 [U-Boot] [PATCH] arm: add 8-byte alignment for ABI compliance before board_init_f Heiko Schocher
2010-11-12  7:06 ` Reinhard Meyer
2010-11-12  7:19   ` Heiko Schocher
2010-11-12  8:04     ` Albert ARIBAUD
2010-11-12  8:50     ` Graeme Russ
2010-11-12  8:50   ` Wolfgang Denk
2010-11-12  9:47     ` Graeme Russ
2010-11-12  9:56       ` Wolfgang Denk
2010-11-12  7:53 ` Albert ARIBAUD [this message]
2010-11-12  8:05   ` Heiko Schocher
2010-12-08 22:50 ` Wolfgang Denk

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