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Re: Boot time memory allocation

To: Mark.Zhan <rongkai.zhan@windriver.com>
Subject: Re: Boot time memory allocation
From: "Alex Gonzalez" <langabe@gmail.com>
Date: Wed, 10 May 2006 10:11:43 +0100
Cc: "Ralf Baechle" <ralf@linux-mips.org>, linux-mips@linux-mips.org
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Thanks for the answers.

I wrongly assumed I wouldn't be able to access unspecified memory
regions, or that I'd have to tweak it somehow.

Regards,
Alex

On 5/10/06, Mark.Zhan <rongkai.zhan@windriver.com> wrote:
Ralf Baechle wrote:
> On Tue, May 09, 2006 at 03:35:14PM +0100, Alex Gonzalez wrote:
>
>> I have two independent processors with access to a shared memory
>> region, mapped in the 256MB to 512MB region (kseg0).
>>
>> One is running a propietary OS, and the second one is running Linux 2.6.12.
>>
>> How would I arrange to leave that shared memory region out of the
>> scope of Linux's memory management system, but at the same time make
>> it possible for a driver to access it?
>>
>> I have done similar things before with the help of alloc_bootmem, but
>> this time I don't want the kernel to reserve the memory, I want the
>> kernel to be completely unaware of it, and I need to specify its start
>> and end.
>
> At kernel initialization time just don't tell the kernel about the
> existence of your memory region.  For many systems that just means you
> shrink the memory region passed to the add_memory_region() call to
> something that suits your platform.
>
>   Ralf
>

Maybe it is a more flexible way to specify the memory regions via
command line. You know, this will produce User-defined memory regions to
kernel.


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