Re: [PATCH 7/9] ARM: move exception vectors away from start of binary

From: Sascha Hauer <s.hauer@pengutronix.de>
To: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 7/9] ARM: move exception vectors away from start of binary
Date: Mon, 23 Jan 2012 13:07:38 +0100	[thread overview]
Message-ID: <20120123120738.GB26642@pengutronix.de> (raw)
In-Reply-To: <20120102150901.GF945@game.jcrosoft.org>

On Mon, Jan 02, 2012 at 04:09:01PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 15:13 Mon 02 Jan     , Sascha Hauer wrote:
> > On Sun, Jan 01, 2012 at 05:37:17AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > On 15:52 Sat 17 Dec     , Sascha Hauer wrote:
> > > > Traditionally U-Boot and barebox have the exception vectors at
> > > > the start of the binary. There is no real reason in doing so,
> > > > because in the majority of cases this data will not be at 0x0
> > > > where it could be used as vectors directly anyway.
> > > > This patch puts the vectors into a separate linker section and
> > > > defines an head function which is placed at the start of the
> > > > image instead. Putting this in a separate function also has
> > > > the advantage that it can be placed at the start of images
> > > > which require an additional header like several Freescale i.MX
> > > > images. As the head function contains the barebox arm magic
> > > > those images can now also be detected aas barebox images.
> > > > 
> > > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > > > ---
> > > I've to make it optionnal as on AT91 for boot we must have it at the bigeniing
> > > of the binary
> > 
> > Instead of this:
> > 
> > 		"b reset\n"
> > 		".rept 7\n"
> > 		".word 0x0\n"
> > 		".endr\n"
> > 
> > we could do this:
> > 
> > 		"b reset\n"
> > 		".rept 7\n"
> > 		"1: b 1b\n"
> > 		".endr\n"
> > 
> > This looks like a exception vector table for the at91 bootloader. BTW
> > I just looked at a at91 datasheet and at least on the at91sam9260 the
> > sixth vector should contain the image size to copy. So maybe this does
> > not work on at91 anyway?
> I'm working on it so please hold on this

ping. I'd really like to merge the remaining thumb2 support pieces.

Sascha

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