Posted on May 17, 2011 at 13:28recently I had similar problems with other GCC and lib. If there are no warnings in compile, this means, that app and lib are compiled in same manner but does not make shure this is correct for STM32.
E.g. the -mfpu=vfp switch instructs the compiler to use instructions for hardware floating point. There is no impact to your app until compiler really uses such instruction (what will end in a exception for STM32)
Make shure, your app (and lib) has been compiled for software float point. If no default, it is either the -msoft-float or -mfloat-abi=soft switch. Probably there are further diffrent stack orders and float formats possible with the GCC.
Make shure, your search path in the linker file points to directory of correct version of libm.a what should be normally the version compiled for ARMv7, Thumb2, no interwork, little endian, software float to be compatible for STM32.
If you have the things workig, it would be interesting how much the lib code contributes using printf with integer and / or float conversion.
