Booting process & memory layout.

Francois-Rene Rideau
Thu Mar 11 18:30:53 CET 2004

On Thu, Mar 11, 2004 at 05:53:22PM +0100, Oleg Gusev wrote:
>   as i have already written, there are problems with the virtual
>   memory mapping in the kernel: i can't read first 8 pages
>   through /dev/mem.
Weird. What are the symptoms?

>   If the kernel image is substantially
>   changed (all the modules are removed) it is also
>   impossible to write to the famous 5c000 page.
I can't understand the causality of this all.
What you prevent writing to this page?
What command are you using?

>   Reserving 2 megabytes for wince stuff in the current kernel is too much.
If you read arch/arm/mm/init.c you'll see that we do not reserve them anymore:
only the page 0xc005c000 is reserved. The 2 megabytes limit is only there
to ensure we can boot properly despite any mapping that survives from WinCE.

As for chaning the bootloader from hpcboot to something else, well sure,
but unless we need change kernel parameters at boot time (do we?), then
it's not urgent. Better hack kernel 2.6 or get UCB1x00 working...

PS: I've just bought off eBay a unit with 32MB RAM...

[ François-René ÐVB Rideau | Reflection&Cybernethics | ]
[  TUNES project for a Free Reflective Computing System  |  ]
What we Are is God's gift to us.
What we Become is our gift to God.

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