Hello, I am new to freeRTOS and tried running it on an STM32F405 chip. For that, I used the port files from /portable/GCC/ARM_CM4F and for the config file I used the file from the github-repo (not allowed to post links) AndColla/stm32f4discovery-freertos-makefile because it also uses libopencm3. …

I read out the address 0xE000ED08 via USB-serial that I have already implemented. It turns out that the bootloader sets the vector table address to 0x08000000. That also explains why the handlers don’t work. Out of curiosity, I have overwritten the value at 0xE000ED08 with 0x800C000 and now the tas…

did you possibly not enable interrupts at rtos startup?

I think they are enabled in the port.c file function prvPortStartFirstTask() __asm volatile ( " ldr r0, =0xE000ED08 \n"/* Use the NVIC offset register to locate the stack. */ " ldr r0, [r0] \n" " ldr r0, [r0] \n" " msr msp, r0 \n"/* Set the msp back to the …

ok, next step would be to ensure that your gpio setup works - can you control your LEDs successfully before OS start? Meaning your gpio assignments and peripheral clock setup is ok? Maybe everything does work except you do not see anything… :smirk:

Good idea, I tested this already (is my debug method). I can control the LEDs until svc 0 is called. In short: LED works before xTaskCreate() and after it LED works before vTaskStartScheduler() LED does not work after vTaskStartSchedular() due to it blocking.

I’m not familiar with libopencm3 but maybe there is an issue with the FreeRTOS awareness means the 3 exception handlers mandatory for FreeRTOS. Have a look here if it brings you a step further: [image] FreeRTOS newbie - STM32F103 + libopenCM3 + build errors Kernel Thanks …

How do you know that you do not end up in a fault? You could toogle the LED in the fault handler to test that. If the code ends up in an exception (as it does most likely), check the usual suspects (irq priority ordering, task stack issues, wrong critical section handling).

I see that you are mapping FreeRTOS handlers to your handlers - RT3s_Firmware/FreeRTOSConfig.h at freertos · Hackertreff-Reutte/RT3s_Firmware · GitHub Can you verify that this SVC handler is getting called?

I am not sure on how I can verify that it is called. If I try to turn on a LED in this function it won’t turn on. I looked in the elf file and found the following entries in the vector_table ... 0800c00c c9 ce 00 08 vector_t blocking_handler+1 hard_fault 0800c010 c9 ce 00 08 vector_…

That’s what I guessed. And following [image] FreeRTOS newbie - STM32F103 + libopenCM3 + build errors The PendSV handler is intended to be the ISR, not to be called from the ISR. If the PendSV handler is called from the ISR, and if the ISR uses stack, the PendSV handler can’t do its job properly.…

As far as I have understood the post I need to write the defines correctly so that the FreeRTOS functions are used in the ISR. I have done this already in my config file #define vPortSVCHandler sv_call_handler #define xPortPendSVHandler pend_sv_handler #define xPortSysTickHandler sys_tick_handler …

FreeRTOS does not execute first task after 'svc 0' call

Kernel

hs2 (Hartmut Schaefer) November 5, 2022, 4:04pm 10

That’s what I guessed. And following

could hopefully solve the problem. @jefftenney is an expert
Are there any hints from the libopencm3 community regarding integration or conflicts with FreeRTOS ?

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FreeRTOS does not execute first task after 'svc 0' call

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