On 2015-09-25 12:21, Daniel Gutson wrote:
El 25/9/2015 13:17, "sudarshan.rajagopalan"
<sudarshan.rajagopa...@vecna.com> escribió:
>
> On 2015-09-25 11:06, Daniel Gutson wrote:
>>
>> On Thu, Sep 24, 2015 at 4:49 PM, sudarshan.rajagopalan
>> <sudarshan.rajagopa...@vecna.com> wrote:
>>>
>>> Hey all,
>>>
>>> We are developing a new BSP that uses math.h in few of the BSP
files. I do
>>
>>
>> May I ask why do you need floating point operations in a kernel?
At
>> least, what sort of operations and why not move them upwards.
>
>
> We are doing floating point operations in one of the device drivers
as part of the BSP - to perform buadrate calculation, to be specific,
which involes inverse operations and using roundf().
How will you handle fp exceptions?
Did you consider using fixed point?
We haven't implemented any error handling yet. We will do so in our next
phase. And I think we decided to use floating-point due to the available
FPU hardware support in the processor( ARM Cortex-M4 and M7) to make
these operations faster. Are there any concerns that we should be aware
of while using floating-point operations in the BSP?
>
>
>>
>>> understand that the math library functions are not part of
standard C
>>> library and has to be linked using "-lm". So I include "LD_LIBS
+= -lm" in
>>> the custom .cgf config file but this doesn't seem to work. I
think this has
>>> to be linked in a proper order. Could someone help with this?
>>>
>>> Heres the custom config file:
>>>
>>> include $(RTEMS_ROOT)/make/custom/default.cfg
>>>
>>> RTEMS_CPU = arm
>>>
>>> LD_LIBS += -lm
>>>
>>> CPU_CFLAGS = -march=armv7-m -mthumb
>>>
>>> CFLAGS_OPTIMIZE_V = -O0 -g -mfloat-abi=hard -mfpu=fpv4-sp-d16
>>>
>>> Thanks and Regards,
>>> Sudarshan
>>> _______________________________________________
>>> devel mailing list
>>> devel@rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel [1]
>
>
Links:
------
[1] http://lists.rtems.org/mailman/listinfo/devel
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