floating point support

nobody wrote on Monday, May 07, 2007:

Hi everybody,
sorry, but Iam a complete newbie on FreeRTOS here.
My question is, does FreeRTOS support floating point math?
I use the GCC on ARMSAM7x256.

chaalar wrote on Monday, May 07, 2007:

FreeRTOS doesn’t but GCC does. :slight_smile:

nobody wrote on Monday, May 07, 2007:

Hi Çağlar Akyüz
thank you for your response.
Do you know a trick to use floating points on FreeRTOS?
Perhaps: stopping (freezing) RTOS and INTERRUPTS, then perform a
floating point algorithm, go back to RTOS?
Thanks in advance

rtel wrote on Monday, May 07, 2007:

This would only be necessary if the floating point libraries are not re-entrant.  Do you know if this is the case or not?  I suspect they are re-entrant, in which case you do not need to take any special measures in order to use floating point from within a task (other than ensuring the task has enough stack space to call the library functions).


chaalar wrote on Monday, May 07, 2007:

If you want to stop scheduler or interrupts you can but I don’t think it is something desirable.
Besides it is something application specific.

Moreover, SAM7X do not have a floating-point hardware. That’s make floating point code nothing different, from the
rtos point of view. That’s a matter of fact for the compiler-library couple.

What I want to say is just implement your favourite algorithm, measure the results. if you *need* more time then you can
always think about disabling interrupts/scheduler.

I hope I get the point.

Best Regards

nobody wrote on Monday, May 07, 2007:

many thanks to Richard and Çağlar Akyüz.
Great help for my next steps with FreeRTOS.
Best Regards