issue about CONFIG_PPC_MMU and CONFIG_SMP define

Becky Bruce becky.bruce at
Wed Mar 12 02:53:15 EST 2008

On Mar 10, 2008, at 3:15 PM, jie han wrote:

> Hi guys,
> I want to simulate compile mutli-core using sequoia(IBM/AMCC 44x  
> processor) source code under kernel arch/powerpc directory.I want  
> to define CONFIG_SMP, I sould define CONFIG_STD_MMU at first,but  
> AMCC 44x don't need to config CONFIG_STD_MMU.Is CONFIG_STD_MMU just  
> for freescale chip? How can I do next? Thanks ahead for your help,

STD_MMU is for all powerpc cpus with a non-BookE MMU.  That includes  
all the 64-bit parts from IBM to date, pasemi's parts, and 32-bit  
parts from IBM & Freescale like the 6xx, 7xx, 7xxx, e600 e300, etc.   
You cannot set this for 44x, because it is a BookE part.

BTW, there's no real relationship between STD_MMU and SMP.  It was  
just a convenient way to restrict the SMP config option in the  
kernel, since all the Linux configs that currently support SMP are  
STD_MMU. We will have BookE configs in the future that do support  
SMP, at which point arch/powerpc/platforms/Kconfig.cputype will be  
changed to allow SMP to be set for those configs.

You can't enable SMP on 44x right now.  It's not supported.


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