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[#1]

S32K358 + FreeRTOS: Random HardFault during PendSV_Handler

Hi Team,

I am facing a random HardFault issue on an S32K358 running FreeRTOS.

The application runs normally for a long duration and then suddenly hangs. After the system stops executing, the Software Watchdog (SWT) is not serviced and eventually resets the controller.

The failure is not immediate—it occurs after approximately 1 to 2 hours of continuous execution

When halted after the failure, the call stack shows:

PendSV_Handler()

↓

HardFault_Handler()

Register values:

LR = 0xA5A5A5A5

PC = 0x00407BD9

LR = 0xA5A5A5A5 looks like a memory initialization pattern rather than a valid return address.

Other registers:

R0 = 0x204011A8

R3 = 0x2040012C

R12 = 0x20400010

Any suggestions or debugging recommendations would be greatly appreciated.

Re: S32K358 + FreeRTOS: Random HardFault during PendSV_Handler

Hi @nirmal_masilamani,

It looks like the task context saved during the FreeRTOS context switch has been corrupted.
PendSV is used by FreeRTOS for context switching, therefore, if the HardFault occurs inside PendSV_Handler(), it often means the scheduler is attempting to restore an invalid task context.
One possible root cause is a task stack overflow. I would recommend increasing the stack size of the tasks and enabling FreeRTOS stack overflow detection:

configCHECK_FOR_STACK_OVERFLOW

Implement: vApplicationStackOverflowHook().

Additionally, you can periodically monitor the remaining stack space of each task using uxTaskGetStackHighWaterMark(). This can help identify tasks that are running close to their stack limits before the fault occurs.

Regards,

Daniel

Re: S32K358 + FreeRTOS: Random HardFault during PendSV_Handler

Hello @danielmartynek ,

Thank you for response,

I already tried increased stack size, enabled stack overflow hook.

Added debug CAN msg in overflow hook, I am not receiving that message when fault occur.

Also monitoring uxTaskGetStackHighWaterMark(), when fault occur

Task 1 : 1977 × 4 ≈ 7908 bytes free

Task 2: 1971 × 4 ≈ 7884 bytes free

Task 3: 3988 × 4 ≈ 15952 bytes free