Any docments analyzing linuxppc kernel and it's policy?

Any docments analyzing linuxppc kernel and it's policy?

[Gong Zhuo]

Hi:
  I am reading the source code of linuxppc mm.  It seems that the process
uses the logical address 0 - 0x7fffffff, and the kernel uses the logical
address 0xc0000000 -- (0xc0000000 + maxium memory). The rest logical address
will not be used by anyone. Am I right?
  Is there any document analyzing the linuxppc kernel and how does the
kernel arrange all the logical space ?


Thanks
Gong Zhuo


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Re: Any docments analyzing linuxppc kernel and it's policy?

[Dan Malek]

Gong Zhuo wrote:

>   I am reading the source code of linuxppc mm.

Okay.......

> ....  It seems that the process
> uses the logical address 0 - 0x7fffffff, and the kernel uses the logical
> address 0xc0000000 -- (0xc0000000 + maxium memory). The rest logical address
> will not be used by anyone. Am I right?

You got the user process part right.....The kernel will map anything
over 0x80000000 in a variety of useful and interesting ways.  The system
memory is usually mapped to 0xc0000000, the remainder of the space is
used for mapping I/O devices, other pages of memory with different
attributes (uncached for example).  This is processor/board dependent,
so there are many different mappings for this space, although we do
try to keep them somewhat consistent.

>   Is there any document analyzing the linuxppc kernel and how does the
> kernel arrange all the logical space ?

I don't know.  I do know this could change daily.....


	-- Dan

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Re: Any docments analyzing linuxppc kernel and it's policy?

[Graham Stoney]

Gong Zhuo writes:
>   Is there any document analyzing the linuxppc kernel and how does the
> kernel arrange all the logical space ?

Check out Dan's answer from last time this FAQ was asked, at:
    http://lists.linuxppc.org/listarcs/linuxppc-embedded/200005/msg00157.html

You can find this link in the "Memory Map" section of the HOWTO at:
http://members.nbci.com/_XMCM/greyhams/linux/PowerPC-Embedded-HOWTO-8.html#ss8.2

Regards,
Graham
--
Graham Stoney
Principal Hardware/Software Engineer
Canon Information Systems Research Australia
Ph: +61 2 9805 2909  Fax: +61 2 9805 2929

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