[PATCH] arm/tegra: select AUTO_ZRELADDR by default

Stephen Warren swarren at nvidia.com
Fri Oct 14 10:45:15 EDT 2011


Russell King wrote at Friday, October 14, 2011 1:15 AM:
> On Thu, Oct 13, 2011 at 04:38:46PM -0700, Olof Johansson wrote:
> > Hi,
> >
> > On Wed, Sep 28, 2011 at 10:50 AM, Stephen Warren <swarren at nvidia.com> wrote:
> > > Peter De Schrijver wrote at Tuesday, September 27, 2011 7:08 PM:
> > >> This patch causes the kernel uncompressor to determine the physical address
> > >> of the SDRAM at runtime. This allows the kernel to boot on both tegra20 and
> > >> tegra30 even though SDRAM is at different physical addresses on both SoCs.
> > >>
> > >> Signed-off-by: Peter De Schrijver <pdeschrijver at nvidia.com>
> > >
> > > An alternative would be to simply add that config option to the relevant
> > > defconfig/.config file. I see both cases in use in the kernel. Still, the
> > > code change this enables looks fine to just turn on all the time, and will
> > > be needed for Tegra30 support, so I'm fine just selecting it as you have.
> > >
> > > Acked-by: Stephen Warren <swarren at nvidia.com>
> > >
> > >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > >> index 472a7f8..474737b 100644
> > >> --- a/arch/arm/Kconfig
> > >> +++ b/arch/arm/Kconfig
> > >> @@ -596,6 +596,7 @@ config ARCH_TEGRA
> > >>       select HAVE_CLK
> > >>       select HAVE_SCHED_CLOCK
> > >>       select ARCH_HAS_CPUFREQ
> > >> +     select AUTO_ZRELADDR
> > >>       help
> > >>         This enables support for NVIDIA Tegra based systems (Tegra APX,
> > >>         Tegra 6xx and Tegra 2 series).
> > >
> > > P.S. Since this patch relates to Tegra, you should CC the Tegra maintainers
> > > and list; I've done so on this message. I also added Arnd; he might take
> > > this through the arm-soc tree.
> >
> > While it does touch a file outside of arch/arm/mach-tegra, it's for
> > the tegra options and is not likely to cause conflicts upstream. I'll
> > apply it with the rest of tegra patches for 3.2 here.
> >
> > So: Applied, thanks.
> 
> I'll point out that this makes Tegra incompatible with ZBOOT_ROM, which
> can still be enabled.  ZBOOT_ROM=y AUTO_ZRELADDR=y is an invalid
> configuration at runtime.

I see that at least one machine solves that by doing:

config ARCH_EP93XX
...
        select AUTO_ZRELADDR if !ZBOOT_ROM

That said, given the way Tegra works, ZBOOT_ROM isn't useful; typically,
systems don't use NOR flash for storage of the kernel, so I don't think
ZBOOT_ROM is likely to be used. Perhaps we should just depend on !ZBOOT_ROM?

-- 
nvpublic




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