Access to first 0x1000 byte on imx53/imx6

[Jan Lübbe]

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 at 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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