From: "Jan Lübbe" <jlu@pengutronix.de>
To: barebox@lists.infradead.org
Subject: Re: Access to first 0x1000 byte on imx53/imx6
Date: Fri, 30 Jan 2015 10:58:27 +0100 [thread overview]
Message-ID: <1422611907.12367.12.camel@pengutronix.de> (raw)
In-Reply-To: <20150130074017.GP12209@pengutronix.de>
On Fr, 2015-01-30 at 08:40 +0100, Sascha Hauer wrote:
> On Thu, Jan 29, 2015 at 08:25:54PM +0100, Robert Jarzmik wrote:
> > Sascha Hauer <s.hauer@pengutronix.de> writes:
> >
> > > On Thu, Jan 29, 2015 at 10:12:46AM +0100, Wjatscheslaw Stoljarski
> wrote:
> > >> Hello,
> > >>
> > >> If I try to read from first 4k RAM on imx53/imx6, with md or from
> code,
> > >> barebox show stacktrace with mesage:
> > >> "unable to handle NULL pointer dereference at address 0x...".
> > >> Is it possible in some way do that?
> > >
> > > The only way I know is to disable CONFIG_MMU in the config.
> > I think the solution in arch/arm/boards/mioa701/board.c (remapping
> the 0x0
> > address) should work here :
> > docg3_iospace = map_io_sections(0x0, (void *)0xe0000000,
> 0x2000);
>
> We could create a /dev/zeropage with the code above. That would make
> the zero page generally available. I don't know if this is worth the
> effort though.
Couldn't we special-case the zero page in /dev/mem instead?
Regards,
Jan
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next prev parent reply other threads:[~2015-01-30 9:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-29 9:12 Wjatscheslaw Stoljarski
2015-01-29 9:21 ` Sascha Hauer
2015-01-29 19:25 ` Robert Jarzmik
2015-01-30 7:40 ` Sascha Hauer
2015-01-30 9:58 ` Jan Lübbe [this message]
2015-01-30 18:51 ` Robert Jarzmik
2015-02-02 9:14 ` Sascha Hauer
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