How to use Math Library in MQX KSDK

[homarpizar]

When I try to use any function of the Math.h using KDS MQX, when I compile it show me next error:

I´d already included the <math.h> library.

Does someone knows how can i solve this problem?

Original Attachment has been moved to: dac_adc_1.zip

[ivadorazinova]

Hello Homar,

please, what do you try for the project? Can you upload it? Or can you send the part of code where you include the Math.h ?

Best Regards,

Iva

[homarpizar]

Hi Iva,

Sure, I've already upload the project.

The problem occurs in the main.c at the line 314.

If it could help, I based the project on the next article:

How To: Create a New MQX RTOS for KSDK Project in KDS

Regards.

Omar.

[ivadorazinova]

Hello Homar,

I´m sorry for my late response. Please, can you try CMSIS library?

Math library is optimized for the M4 core and uses M4 core instructions.

Tutorial: Using the ARM CMSIS Library | MCU on Eclipse

Let me know, if it helps.

Best Regards,

Iva

[homarpizar]

Hi, Iva.

I just watch something weird, when I use any function of <math.h> if I use :

sqrt(100);

Everything it´s OK, the project runs normally.

But when I use:

variable=100;

root= sqrt(variable);

The project doesn't runs.

Could you help me?

Best Regarts.

Omar

[BlackNight]

Hi Omar,

have you included math.h with

#include <math.h>

?

And if you compile your code, there are no compiler warnings?

And what does mean "the project doesn't run" exactly?

Thanks,

Erich

[homarpizar]

Hello Erich,

I included math.h with #include <math.h>.

Despite that, if I use any math function like this:

variable=100;

root= sqrt(variable);

When I compile, it appears:

But if I want to use constants as parameter or when the parameter it´s declared as " #define PARAM 100", like this:

sqrt(100);

or

#define PARAM 100

...

...

...

sqrt(PARAM);

And then I compile, no errors or warnings appearing.

I have done each step following this: How To: Create a New MQX RTOS for KSDK Project in KDS  and I´m using the FRDM-K64.

I hope you can help me.

Thanks.

Omar

[BlackNight]

Hi Omar,

can you share what is shown in the Console view (build output)?

The console view shows more details than the Problems view.

Erich

[homarpizar]

Hello Erich,

Here is the result of the console view:

'Building target: K64_MQX_KSDK_Example.elf'

'Invoking: Cross ARM C++ Linker'

arm-none-eabi-g++ -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -O0 -fmessage-length=0 -fsigned-char -ffunction-sections -fdata-sections  -g3 -T C:\Freescale\KSDK_1.2.0\platform\devices\MK64F12\linker\gcc\MK64FN1M0xxx12_flash.ld -nostartfiles -nodefaultlibs -Xlinker --gc-sections -LC:\Freescale\KSDK_1.2.0\lib\ksdk_mqx_lib\kds\K64F12\debug -LC:\Freescale\KSDK_1.2.0\rtos\mqx\lib\frdmk64f.kds\debug\mqx_stdlib -LC:\Freescale\KSDK_1.2.0\rtos\mqx\lib\frdmk64f.kds\debug\mqx -Wl,-Map,"K64_MQX_KSDK_Example.map" -Xlinker --cref -Xlinker -static  -Xlinker -z -Xlinker muldefs  -Xlinker --undefined=__isr_vector  -Xlinker --defsym=__stack_size__=0x400  -Xlinker --defsym=__heap_size__=0x200 -o "K64_MQX_KSDK_Example.elf"  ./Sources/LED_RGB.o ./Sources/fsl_pit_irq.o ./Sources/main.o ./Sources/pdb_trigger.o  ./KSDK_Files/board.o ./KSDK_Files/gpio_pins.o ./KSDK_Files/pin_mux.o  ./Debug_Console/fsl_debug_console.o ./Debug_Console/fsl_misc_utilities.o ./Debug_Console/print_scan.o  ./BSP_Files/init_bsp.o ./BSP_Files/mqx_main.o  C:/Freescale/KSDK_1.2.0/lib/ksdk_mqx_lib/kds/K64F12/debug/libksdk_platform_mqx.a C:/Freescale/KSDK_1.2.0/rtos/mqx/lib/frdmk64f.kds/debug/mqx_stdlib/lib_mqx_stdlib.a C:/Freescale/KSDK_1.2.0/rtos/mqx/lib/frdmk64f.kds/debug/mqx/lib_mqx.a -lksdk_platform_mqx -l_mqx_stdlib -l_mqx -lgcc -lc -lsupc++ -lm -lnosys

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libm.a(lib_a-w_sqrt.o): In function `sqrt':

w_sqrt.c:(.text.sqrt+0x40): undefined reference to `__aeabi_dcmplt'

w_sqrt.c:(.text.sqrt+0x92): undefined reference to `__aeabi_ddiv'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libm.a(lib_a-e_sqrt.o): In function `__ieee754_sqrt':

e_sqrt.c:(.text.__ieee754_sqrt+0x156): undefined reference to `__aeabi_dmul'

e_sqrt.c:(.text.__ieee754_sqrt+0x15e): undefined reference to `__aeabi_dadd'

e_sqrt.c:(.text.__ieee754_sqrt+0x182): undefined reference to `__aeabi_dsub'

e_sqrt.c:(.text.__ieee754_sqrt+0x18a): undefined reference to `__aeabi_ddiv'

collect2.exe: error: ld returned 1 exit status

make: *** [K64_MQX_KSDK_Example.elf] Error 1

Thanks for helping.

Omar

[BlackNight]

It is a problem of your linker settings. You have both -nostartfiles and -nodefaultlibs enabled, so the linker does not link with the standard libraries (which include the math functions).

Try these settings:

I hope this helps,

Erich

[homarpizar]

I tried as you show me,

But now it is shown:

'Building target: K64_MQX_KSDK_Example.elf'

'Invoking: Cross ARM C++ Linker'

arm-none-eabi-g++ -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -O0 -fmessage-length=0 -fsigned-char -ffunction-sections -fdata-sections  -g3 -T C:\Freescale\KSDK_1.2.0\platform\devices\MK64F12\linker\gcc\MK64FN1M0xxx12_flash.ld -Xlinker --gc-sections -LC:\Freescale\KSDK_1.2.0\lib\ksdk_mqx_lib\kds\K64F12\debug -LC:\Freescale\KSDK_1.2.0\rtos\mqx\lib\frdmk64f.kds\debug\mqx_stdlib -LC:\Freescale\KSDK_1.2.0\rtos\mqx\lib\frdmk64f.kds\debug\mqx -Wl,-Map,"K64_MQX_KSDK_Example.map" -Xlinker --cref -Xlinker -static  -Xlinker -z -Xlinker muldefs  -Xlinker --undefined=__isr_vector  -Xlinker --defsym=__stack_size__=0x400  -Xlinker --defsym=__heap_size__=0x200 -o "K64_MQX_KSDK_Example.elf"  ./Sources/main.o  ./KSDK_Files/board.o ./KSDK_Files/gpio_pins.o ./KSDK_Files/pin_mux.o  ./Debug_Console/fsl_debug_console.o ./Debug_Console/fsl_misc_utilities.o ./Debug_Console/print_scan.o  ./BSP_Files/init_bsp.o ./BSP_Files/mqx_main.o  C:/Freescale/KSDK_1.2.0/lib/ksdk_mqx_lib/kds/K64F12/debug/libksdk_platform_mqx.a C:/Freescale/KSDK_1.2.0/rtos/mqx/lib/frdmk64f.kds/debug/mqx_stdlib/lib_mqx_stdlib.a C:/Freescale/KSDK_1.2.0/rtos/mqx/lib/frdmk64f.kds/debug/mqx/lib_mqx.a -lksdk_platform_mqx -l_mqx_stdlib -l_mqx -lgcc -lc -lsupc++ -lm -lnosys

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-signalr.o): In function `_kill_r':

signalr.c:(.text._kill_r+0xe): undefined reference to `_kill'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-signalr.o): In function `_getpid_r':

signalr.c:(.text._getpid_r+0x0): undefined reference to `_getpid'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-closer.o): In function `_close_r':

closer.c:(.text._close_r+0xc): undefined reference to `_close'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-fstatr.o): In function `_fstat_r':

fstatr.c:(.text._fstat_r+0xe): undefined reference to `_fstat'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-isattyr.o): In function `_isatty_r':

isattyr.c:(.text._isatty_r+0xc): undefined reference to `_isatty'

c:/freescale/kds_3.0.0/toolchain/bin/../lib/gcc/arm-none-eabi/4.8.4/../../../../arm-none-eabi/lib/armv7e-m/fpu\libc.a(lib_a-lseekr.o): In function `_lseek_r':

lseekr.c:(.text._lseek_r+0x10): undefined reference to `_lseek'

collect2.exe: error: ld returned 1 exit status

make: *** [K64_MQX_KSDK_Example.elf] Error 1

[BlackNight]

It seems that this MQX project somehow has additional dependency e.g. on some I/O functions.

I see you have

-lnosys

in your linker flags: try to remove that option and instead link with the system library?

Erich

[homarpizar]

I removed nosys from the Cross ARM C++ Linker Libraries, but I don´t know how to link with the system library.

Can you help me, please?

Omar