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From: Lucas Stach <dev@lynxeye.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arm: armv7: add compile option -mno-unaligned-access if available
Date: Mon, 02 Jul 2012 17:16:08 +0200	[thread overview]
Message-ID: <1341242168.1392.2.camel@tellur> (raw)
In-Reply-To: <yw1xtxxqv69l.fsf@unicorn.mansr.com>

Am Montag, den 02.07.2012, 10:53 +0100 schrieb M?ns Rullg?rd:
> Tetsuyuki Kobayashi <koba@kmckk.co.jp> writes:
> 
> > Recent compiler generates unaligned memory access in armv7 default.
> > But current U-Boot does not allow unaligned memory access, so it causes
> > data abort exception.
> > This patch add compile option "-mno-unaligned-access" if it is available.
> 
> Why not allow unaligned accesses instead?
> 
IMHO, our recent discussion showed that both ways are wrong.
"-mno-unaligned-access" works around misaligned data on the software
level, while allowing unaligned access does on the hardware level.

What we really want is no unaligned access in U-Boot at all. Just
because "-mno-unaligned-access" is the default on ARMv5, we should not
consider it a gold standard.

Thanks,
Lucas

  reply	other threads:[~2012-07-02 15:16 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-05 17:47 [U-Boot] [PATCH] arm: enable unaligned access on ARMv7 Lucas Stach
2012-06-05 18:42 ` Stephen Warren
2012-06-05 19:06   ` Lucas Stach
2012-06-22  9:15     ` Albert ARIBAUD
2012-06-22  9:36       ` Lucas Stach
2012-06-22 11:16         ` Albert ARIBAUD
2012-06-22 11:47           ` Lucas Stach
2012-06-22 22:11             ` Aneesh V
2012-06-22 22:13               ` Aneesh V
2012-06-23  9:01                 ` Albert ARIBAUD
2012-06-23 17:43                   ` V, Aneesh
2012-06-25 20:34                     ` Albert ARIBAUD
2012-06-25 21:49                       ` Aneesh V
2012-06-25 22:02                         ` Wolfgang Denk
2012-06-23 19:50                   ` Måns Rullgård
2012-06-24  6:30                   ` Lucas Stach
     [not found]                     ` <20120625221741.3a32790e@lilith>
2012-06-25 21:34                       ` Lucas Stach
2012-06-26 20:56       ` Rob Herring
2012-06-27 10:14         ` Tetsuyuki Kobayashi
2012-07-02  9:42           ` [U-Boot] [PATCH] arm: armv7: add compile option -mno-unaligned-access if available Tetsuyuki Kobayashi
2012-07-02  9:53             ` Måns Rullgård
2012-07-02 15:16               ` Lucas Stach [this message]
2012-07-02 16:14                 ` Måns Rullgård
2012-07-03  7:10                   ` Tetsuyuki Kobayashi
2012-07-05  7:57                   ` Albert ARIBAUD
2012-07-18 21:37                     ` Albert ARIBAUD
2012-07-19  4:31                     ` Mike Frysinger
2012-07-19  4:29                   ` Mike Frysinger
2012-07-19  6:28                     ` Albert ARIBAUD
2012-07-19 14:27                       ` Mike Frysinger
2012-07-20  7:12                         ` Albert ARIBAUD
2012-07-12 15:12             ` Gary Thomas

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