Hello! I’m trying to slip FreeRTOS under Marlin (the 3D Printing firmware) and have run into a problem. I want to keep trying to xCreateTask() with decreasing amounts of stack memory until the task starts successfully. In order to do that, I need configUSEMALLOCFAILED_HOOK=0 (or else the malloc() routines will lock up with the board’s LED blinking). I can’t do that because vTaskStartScheduler() makes a call to vApplicationMallocFailedHook(); Can we make a small change in the release version of FreeRTOS as described below? It is easy enough to make the change, but the distribution of the needed change is difficult. Marlin uses the GNU license and it would be messy for use to distribute a modified version of FreeRTOS. ~~~ void initVariant(void) {

if defined(USBCON)

USBDevice.attach();

endif

setup();        // the normal Arduino setup() function is run here.

vTaskStartScheduler(); // initialise and run the freeRTOS scheduler. Execution should never return here.

if ( configUSEMALLOCFAILED_HOOK == 1 )

vApplicationMallocFailedHook(); // Probably we've failed trying to initialise heap for the scheduler. Let someone know.

endif

HANG: goto HANG; return; } ~~~

You can implement vApplicationMallocFailedHook() to do whatever you want. It sounds like you have default debug configuration that is just halting execution if it is called, but normally in production code an allocation failure would be handled gracefully (as you are trying to do) rather than be considered a fatal error. The call to vApplicationMallocFailedHook() after vTaskStartScheduler() appears to be obsolete as if the scheduler can’t start, then it failed to create the stack for either the idle or timer task, in which case vApplicationMallocFailedHook() will already have been called.

May I request we delete the obsolete call to vApplicationMallocFailedHook() after vTaskStartScheduler() for the next release? I’m hoping I can get everything working with no code changes to the FreeRTOS library for Arduino! 🙂

That main file is not something we provided :o) Please submit this request to whomever supplied it.