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STM32MP1 support available in SW4STM32

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world.
And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4; you can download a short video showcasing this on the ac6-tools website (registration required).

System Workbench for STM32


sprinf conversion of float is not working for STM32F7

I’m tryint to use sprintf to convert a float to a string, but the returned string is empty (just the ‘\0’ is returned).
Do any of you know of a trick that can make it work?

I’m using the latest versions of AC6 and the “Hello World” example from cube.

/Breinholm

Tunisia

Hello Breinholm,

Check your linker flags (project properties > C/C++ Build > Setings > Tool Settings (TAB) > MCU GCC Linker > Miscellaneous > Linker flags),
if you are using nanolib “-specs=nano.specs” you need to add “-u _printf_float” to enable float printf.

Best Regards,
TarekB

Hi Tarek,

I treid adding “-u _printf_float” to enable float printf. as you suggest but after build i get the following errors?


Building target: EM34.elf
Invoking: MCU GCC Linker
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” -Wl,-Map=output.map -Wl,--gc-sections -lm -o “EM34.elf” @”objects.list”
arm-none-eabi-gcc.exe: error: _printf_float: No such file or directory
make: *** EM34.elf Error 1

I am using latest updates for STM32 CubeMX, and STM32 Workbench..... I recall this solution used to work on previuos version but not now?
Any suggestions?

Hi,

I think you put the “-u _printf_float” on the wrong place, it should be in the linker flags and not the -Xlinker area.

Regards
Kevin.

Hi Tang,

I am sure I put the options under the Linker Flags, as I said this option was working under previous versions (unsure which version it was) but I recently clicked “update” on both the STM32 CubeMX and the System32 Workbench programs and now for some unlknown reason The Linker throws the following errors:

Building target: EM34.elf
Invoking: MCU GCC Linker
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _sprintf_float -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” -Wl,-Map=output.map -Wl,--gc-sections -lm -o “EM34.elf” @”objects.list”
arm-none-eabi-gcc.exe: error: _sprintf_float: No such file or directory
arm-none-eabi-gcc.exe: error: _printf_float: No such file or directory
make: *** EM34.elf Error 1

(see attached image)


Tunisia

Kevin is right :
“-u _printf_float” should be after “-specs=nano.specs”

Notes :
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _sprintf_float -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” ....

  1. There is no “_sprintf_float”
  2. You do not need Xlinker options
  3. You should have only one -u _printf_float
  4. In (project properties > C/C++ Build > Setings > Tool Settings (TAB) > MCU GCC Linker > Miscellaneous > Linker flags),you should have ” -specs=nosys.specs -specs=nano.specs -u _printf_float”

Many thanks tarek,

My problem issue was that was adding the “-u_printf_float” option using the “ADD ICON” which put the required string into the TEXT BOX below ? ..
This was working ok on previous versions of Sytem32 Workbench ...but ... The Latest version doesn’t work like that anymore ... so what I did was to edit/replace the main string at the top ( -specs=nosys.specs -specs=nano.specs ) to what you have shown above .(-specs=nosys.specs -specs=nano.specs -u _printf_float). this worked OK ..
Thanks again for your help.biggrin