System Workbench for STM32

Hi George,
than you for the tip.
I made some tests and I tried your solution, it works!
Anyway I've been reading the difference between:

• [+]mfloat-abi=soft (software emulated floating point)
• [+]mfloat-abi=softfp (uses FPU instructions, keep compatiblity with non "soft" libraries, but data are loaded into the FPU in a slower way)
• [+]mfloat-abi=hard (best performances, but not compatible with object not generated using hard flag)

https://wiki.debian.org/ArmHardFloatPort/VfpComparison
so when possible hard flag should be used.
If the projct does not use external libraries, is possible to use "hard" flag, but the flag has to be enabled in: GCC compiler, GCC Linker and GCC Assrmbler.
To do so, go to project properties (Alt + Enter), choose C/C++ Build and then settings, then add flags:
http://s16.postimg.org/olvegtf05/Untitled.png

Bye Filippo