Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

RE: Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

lbe — Thu, 06 Dec 2018 15:27:49 GMT

Just to close the bug report....I was able to finally fix the problem. The hardfault was an unauthorized memory access due to the fact that I put a wrong valueas PACKET_PAYLOAD_MAXSIZE on the radio configuration. This was causing problems to the DMA and was messing things up.

Now that I put the correct value the hardfault is not happening again.

RE: Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

lbe — Tue, 04 Dec 2018 08:19:33 GMT

Well, this is getting weirder and weirder....I'll describe you what happens. So, I enabled the log module (I am using RTT, with a dev board connected to the computer and the SES in debug mode) and I changed the compiler optimization level. Here I obtain the first weird behavior: if the optimization level in SES is set to "Debug" (I don't see the "level 0" among the options) I don't have an Hardfault. I tried restarting several times and I never end in the hardfault routine. If I change the optimization level to "None",

sometimes I fall in the hardfault routine, BUT

- when the code stops at the beginning of the assembler code (in hardfault_handler_gcc.c), if I press the "continue" button of the debugger (green arrow), then my code resumes execution: I never get to the breakpoint I set in the hardfault_implementation.gcc file

- If I go step by step by pressing F10, sometimes I get to the hardfault_implementaion breakpoint, where the p->stack is 0 and apparently the cfsr_msg is number [18] = "The processor has attempted an illegal load of EXC_RETURN to the PC, as a result of an invalid context, or an invalid EXC_RETURN value"

Sometimes, though, even if I go step by step, I end in nrf_log_backend_panic_set (in nrf_log_backend_interface), which seems to be related to a problem with the logger module?

I am completely lost,so I wait for clues on how to proceed. Thanks a lot.

RE: Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

haakonsh — Mon, 03 Dec 2018 15:48:32 GMT

Aah. That whole section will get optimized out by the compiler. You need to enable the log module and set the compiler optimization level to 0. Are you using RTT or UART as the backend for the log module?

RE: Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

lbe — Mon, 03 Dec 2018 15:36:18 GMT

Hello,

thanks for your reply. Actually, I already tried what you suggested, but line 109 is not accepted as a valid breakpoint (the question mark you see on the left side of the code in Segger Embedded Studio). So, I put a breakpoint on a couple of line before [ uint32_t cfsr = SCB->CFSR;].

The problem is that the debugger correctly halts there, but then if I go through step by step, the debugger goes directly to line 148 [NRF_BREAKPOINT_COND;].

And if I try to read the p_stack information, it is always empty (0x000000).

I figured a way to temporarily avoid the Hardfault by changing a parameter in my protocol, but it is not a final solution, so I definitely need to understand what kind of hardfault I am getting so that I can find a solution.

Any other clue on how to obtain this information?

Thank you

RE: Hardfault Handler implementation library - not getting NRF_LOG_ERROR info

haakonsh — Mon, 03 Dec 2018 15:17:02 GMT

Put a breakpoint on line 109 of hardfault_implementation.c (SDK15.2) and step through the code to find the hardfault cause. You might want to disable the log module if you get stuck because of Its problems, they might be another symptom of your issue or a completely separate issue that we can handle after we've solved the hardfault issue.