Allocate memory within an application and modify its access permissions

[Gedare Bloom]

Yes I think the RB Heap would be an ideal solution. My intuition is
that the exception is caused exactly by the heap (workspace) metadata
being written, but Hesham should hook up a debugger to verify the
source of the exception.

-Gedare

On Wed, Aug 28, 2013 at 3:00 AM, Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
> On 2013-08-28 02:00, Hesham Moustafa wrote:
>>
>> Hey all,
>>
>> I want to allocate memory within an application code, set
>> memory access attributes on it, and check whether these
>> permissions are set correctly or not.
>>
>> I tried to use _Workspace_Allocate(), malloc(), and partition and region
>> managers to allocate a region of memory, but just after I set the
>> allocated region to READ_ONLY attribute, an exception occurs. There is
>> no problem when I set WRITE attribute. Also when I use hard-coded
>> addresses ( that do not belong to any used section by RTEMS), I get it
>> working correctly.
>
>
> Why do you get an exception?  The heap manager places some administration
> data right at the begin and end of an allocated block.  See also
>
> http://www.rtems.org/onlinedocs/doxygen/cpukit/html/group__RBHeap.html
>
>
>>
>> Is there a way to allocate memory without hard-coded addresses
>> (target-independent), or the previous "exception-after-set" problem ?
>>
>> Regards,
>> Hesham
>> _______________________________________________
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>> rtems-devel at rtems.org
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>>
>
>
> --
> Sebastian Huber, embedded brains GmbH
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