Pass through kernel memory manager

Pass through kernel memory manager

[Paul Chavent]

Hi

I'm working on an ARM926EJS based SOM (OMAPL138). The ARM has internal memory spaces (8k one and 128k one) where i would like to put some code.

I thought to use something like :

void foobar (void) __attribute__ ((section ("bar")));

Then link with

-Wl,--section-start,bar=FFFF1000


But the Linux loader fails to load this segment.

So, is it worth to try to achieve to run code at desired position ?

Is there any way to tell Linux to 1:1 map some physical regions to processes address space ? Perhaps the memmap= kernel parameter ?

Thanks for your help.

Paul.

Pass through kernel memory manager

[Peter Teoh]

the parameter you passed in section start looks weird, given that your
physical memory so limited.   (8K and 128K, 2 different bank? if so then
only one is available at any one time?),

Perhaps some knowledge about linker-script should help:

http://blogs.bu.edu/md/2011/11/15/the-dark-art-of-linker-scripts/

the "1:1" mapping is called identity mapping, and linker script provide a
way for you to load the binary into specific part of the physical memory,



On Sat, Feb 8, 2014 at 4:29 AM, Paul Chavent <paul.chavent@fnac.net> wrote:

> Hi
>
> I'm working on an ARM926EJS based SOM (OMAPL138). The ARM has internal
> memory spaces (8k one and 128k one) where i would like to put some code.
>
> I thought to use something like :
>
> void foobar (void) __attribute__ ((section ("bar")));
>
> Then link with
>
> -Wl,--section-start,bar=FFFF1000
>
>
> But the Linux loader fails to load this segment.
>
> So, is it worth to try to achieve to run code at desired position ?
>
> Is there any way to tell Linux to 1:1 map some physical regions to
> processes address space ? Perhaps the memmap= kernel parameter ?
>
> Thanks for your help.
>
> Paul.
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>



-- 
Regards,
Peter Teoh
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