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Startup failure as timers are enabled (MPU)

Posted by Tamir Michael on July 6, 2012
Hello,

I have the MPU enabled (LPC1788), and just added timer.c and followed the instructions as to how to enable timers.
Unfortunately, as the scheduler tries to start the first stack, I get an immediate "unstacking error" from the MPU.
Any thoughts...?

Thanks in advance

RE: Startup failure as timers are enabled (MPU)

Posted by Tamir Michael on July 6, 2012
Can it be related to the kernel using CreateTask rather than CreateTaskRestricted...?

RE: Startup failure as timers are enabled (MPU)

Posted by Richard on July 6, 2012
I have to admit having not tried it, but I have had a quick look now.

Could you try changing the line in prvSampleTimeNow() from

static portTickType xLastTime = ( portTickType ) 0U;


to

PRIVILEGED_DATA static portTickType xLastTime = ( portTickType ) 0U;


and report back. Thanks.

Regards.

RE: Startup failure as timers are enabled (MPU)

Posted by Tamir Michael on July 6, 2012
I added "|portPRIVILEGE_BIT" at the creation of the timers task and that seems to help!

RE: Startup failure as timers are enabled (MPU)

Posted by Richard on July 6, 2012
You beet me to it! I was just about to say when I read your post (that crossed with mine) that you need to set that in your definition of configTIMER_TASK_PRIORITY. The suggested change made in my previous post should be made too.

I think I will change the core code so the ORing with portPRIVILEGE_BIT is done by the kernel too - just like it is for the idle task.

Regards.

RE: Startup failure as timers are enabled (MPU)

Posted by Tamir Michael on July 6, 2012
Thanks.


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