Re: Linux for Asymmetric Multi Processing Systems.

From: Krishna Chaitanya
Date: Sat May 13 2006 - 08:10:42 EST


Hi Len,

Each Processor has its own RAM and the main ARM9 processor can access
the ARM7 Memory Map through a _Shared RAM_.

In other words, the Memory Map of ARM7 processors is visible to ARM9 processor.

Finally there are 3 RAMs:
1) System RAM (ARM9)
2) Shared RAM (the Common Memory)
3) Local RAM for ARM7s.

Basically, this is a _flexible_ mechanism to control the _visibility_
of Each Processor.

And the Memory Controller can do either _cached_ or _non-cached_ operations.

Regards,
krs

On 5/13/06, Lennart Sorensen <lsorense@xxxxxxxxxxxxxxxxxxx> wrote:
On Fri, May 12, 2006 at 12:24:20PM +0530, Krishna Chaitanya wrote:
> I am working on a project where the hardware is Asymmetric Multi
> Processing Systems(ASMP).
>
> In my system I have one ARM9, four ARM7s'.
>
> 1. Can I use one Linux Kernel for all the CPUs in an ASMP system. (or)
> Should I use One Linux Kernel for ARM9 and RTOSes for ARM7.
> 2. If my hardware would come up in future with another ARM7 does linux
> scale for the new CPU.
>
> Can anyone please direct me to the source/docs how to use Linux for
> ASMP systems.

So you have two different instruction sets (although I think the arm7 is
a subset of the arm9, but what do I know), running different clocks
speeds most likely.

Does each cpu have it's own ram, or do they all share one pool of memory?

How does the Cell processor systems deal with this?

Len Sorensen

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