[PATCH] arm: add default value for PHYS_OFFSET Kconfig setting

Uwe Kleine-König u.kleine-koenig at pengutronix.de
Fri Dec 2 14:07:16 EST 2011


Hello,

On Fri, Dec 02, 2011 at 11:31:50AM -0500, Paul Gortmaker wrote:
> On 11-12-02 04:21 AM, Uwe Kleine-König wrote:
> > Hello Nicolas,
> > 
> > On Fri, Dec 02, 2011 at 12:33:26AM -0500, Nicolas Pitre wrote:
> 
> [...]
> 
> >> And it seems that at91x40 is the only defconfig with MMU=n, so the only 
> >> option is really to provide a default CONFIG_PHYS_OFFSET.  So what about 
> >> this:
> >>
> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> >> index e084b7e981..a24672924f 100644
> >> --- a/arch/arm/Kconfig
> >> +++ b/arch/arm/Kconfig
> >> @@ -222,6 +222,7 @@ config NEED_MACH_MEMORY_H
> >>  config PHYS_OFFSET
> >>  	hex "Physical address of main memory"
> >>  	depends on !ARM_PATCH_PHYS_VIRT && !NEED_MACH_MEMORY_H
> >> +	default DRAM_BASE if !MMU
> >>  	help
> >>  	  Please provide the physical address corresponding to the
> >>  	  location of main memory in your system.
> >>
> >> Eventually the DRAM_BASE config option could simply be replaced by 
> >> PHYS_OFFSET directly, but that's a larger change.
> > I'm working on a MMU-less machine, too and had that change already in my
> > working copy. I was about to commit and it send out later today.
> > 
> > So: Acked-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> 
> Looks fine to me as well; I had no particular attachment to the
> original patch, and you guys have a much better understanding of
> the specifics of the system.
A post-ack comment: would it make sense to make this:

	config PHYS_OFFSET
		hex "Physical address of main memory" if MMU
	...

such that !MMU build don't get a chance to misconfigure it?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |



More information about the linux-arm-kernel mailing list