Can't get vApplicationGetTimerTaskMemory to be recognised

Kernel
1

I have #defined configSUPPORT_STATIC_ALLOCATION as 1, and so I need to define my own versions of vApplicationGetTimerTaskMemory() and vApplicationGetIdleTaskMemory().

Now, if I don’t do that, and try to build, then I get two linker errors, saying that those two functions are undefined. Of course.

If I define those functions, then vApplicationGetIdleTaskMemory() seems to be recognised by the linker, but I still get the error: Undefined reference to ‘vApplicationGetTimerTaskMemory’.

I have carefully checked the function to make sure it matches the prototype found in timers.h. The prototype there is:

    void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
                                         StackType_t ** ppxTimerTaskStackBuffer,
                                         uint32_t * pulTimerTaskStackSize );

My function is:

void vApplicationGetTimerTaskMemory( StaticTask_t **ppxTimerTaskTCBBuffer,
                                     StackType_t  **ppxTimerTaskStackBuffer,
                                     uint32_t      *puxTimerTaskStackSize )
{
    static StaticTask_t xTimerTaskTCB;
    static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];
    *ppxTimerTaskTCBBuffer = &xTimerTaskTCB;
    *ppxTimerTaskStackBuffer = uxTimerTaskStack;
    *puxTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
}

What am I doing wrong?

2

Hi @Rocketmagnet
Welcome to the FreeRTOS Community Forums !
Is configUSE_TIMERS defined in your FreeRTOSConfig.h file?
configUSE_TIMERS should also be set to 1 for the timer APIs like ‘vApplicationGetTimerTaskMemory’.

Also you can instead set configKERNEL_PROVIDED_STATIC_MEMORY to 1 in the FreeRTOSConfig.h to use the kernel provided default implementations of these callbacks.

1 Like
3

could it be that your callbacks are implemented in a cpp file and thus decorated by the compiler? If so, relocate them to a file with the extension .c (easiest solution).

4

Good call. Yes, I’ll try this. Strange though that vApplicationGetIdleTaskMemory() works but vApplicationGetTimerTaskMemory() doesn’t.

5

Hmm. Just noticed that I’d #included “task.h” but not “timers.h”.

When I #included “timers.h” the build worked! Strange, you’d think it wouldn’t because of the decoration.

6

possibly there is an implied

extern “C”

around the prototype which will disable decoration.

7

Yes, the timer file pre-declares the prototype of the function, and that includes the extern “C” part, so if the prototype declaration has been seen, the function will get the right linkage.

8

Thanks for taking the time to report back! It greatly helps other users.