Application stopped after a while


I have updated the board STM32F746G-DISCO ( to add a joystick. After a while, the MicroEJ application is stopped and nothing is able to unlock the situation (joystick / touch / button press, display repaint, timer etc.).

However FreeRTOS keeps working: touch task is running when I play with the touch.
Do you have an idea about this dead lock ?

Thanks for your help

Hi William,

This kind of freeze may come from an issue in the core adaptation layer (LLMJVM_FreeRTOS.c). The MicroJvm virtual machine can be stuck in LLMJVM_IMPL_idleVM() waiting for a resume from LLMJVM_IMPL_wakeupVM().

Did you modify this file?

By default, the FreeRTOS implementation uses a semaphore to suspend and resume the virtual machine. The function LLMJVM_IMPL_wakeupVM() calls xSemaphoreGiveFromISR() if it is executed from an interrupt and xSemaphoreGive() otherwise.

Make sure all your interrupt handlers call the functions interrupt_enter() and interrupt_leave() so that LLMJVM_IMPL_wakeupVM() uses the right function.
See interrupts.h header file for more information.

Best regards,

Hi Jerome.

There is no difference between my LLMJVM_FreeRTOS.c and the one available in STM32F746G-DISCO original platform.

It seems you’re right about the interrupt issue: my joystick interrupt does not update the interrupt flag. I have changed that yesterday and the application is still running this morning.

Thanks for your help