Essential functions of FreeRTOS crash the system.

[Val Gretchev]

Functions xSemaphoreGiveFromISR() and xQueueSendToBackFromISR() called in an ISR cause a system crash and never return. Here is a simple program that illustrates this condition. It is based on your demo code “Blank” and uses the EasyMx PRO v7 for STM32 board with STM32F407VGT6. All explanations and switch settings are given in the example.

These 2 functions are essential to FreeRTOS and should be fixed quickly.

[petar.suknjaja]

Hi Val,
I will review it.
Kind regards,
Petar

[Val Gretchev]

Hello Petar
Is there any news with respect to this problem in FreeRTOS? I know this software does not generate any revenue for Mikroelektronika but it may result in additional hardware purchases. I, and the user community would like an answer soon.
Val Gretchev

[petar.suknjaja]

Hi Val,
I'm sorry, I haven't had time to review it, but I promise I will do it as soon as I finish some previous projects and assignments.
Kind regards,
Petar

[Val Gretchev]

OK Petar
Thanks for the update
Val

[Val Gretchev]

Hi Petar
I believe I found the problem. It appears that FreeRTOSConfig.h file has a trap that checks for interrupt priority 0. See:
#define configASSERT(x) if ((x) == 0) { taskDISABLE_INTERRUPTS(); while (1); }
If you don’t set the priority of an interrupt vector, it defaults to 0.

Solving this problem can be done in 2 ways:
Set the interrupt priority to a non-zero value:
e.g. –
// Set up interrupt vector
NVIC_IntEnable(IVT_INT_EXTI0); // Enable EXTI0 interrupt vector
// Set interrupt priority other than 0
NVIC_SetIntPriority(IVT_INT_EXTI0,_NVIC_INT_PRIORITY_LVL1);
Or, remove the trap in the configASSERT(x) statement.
e.g. –
#define configASSERT(x) if ((x) == 0) {}

Now I can proceed with writing more complicated code. Thanks,
Val

[petar.suknjaja]

Hi Val,
Thank you for letting us know!
Kind regards,
Petar