Math lib inclusion in BSP

sudarshan.rajagopalan sudarshan.rajagopalan at vecna.com
Fri Sep 25 16:17:52 UTC 2015


On 2015-09-25 11:06, Daniel Gutson wrote:
> On Thu, Sep 24, 2015 at 4:49 PM, sudarshan.rajagopalan
> <sudarshan.rajagopalan at 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().

> 
>> 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 at rtems.org
>> http://lists.rtems.org/mailman/listinfo/devel



More information about the devel mailing list