hangs at nrf_fstorage_erase(). (debug shows -> Unknown function at 0x00000978)

[prithvi25]

So I am trying to store a few configuration parameters in flash.

I am using nrf_fstorage for that.

so before storing the parameters, I am erasing the flash but, it hangs at "return (p_fs->p_api)->erase(p_fs, page_addr, len, p_context);" in nrf_fstorage_erase().

How to solve this problem?
Thank you.

[Amanda Hsieh]

Hi, 

Do you use nrf_delay in the project? If so, is it possible to replace with non-blocking delay?

Please see a similar case that might help you.

-Amanda H.

[prithvi25]

I checked it. I have not used any delay API in my project.

[Amanda Hsieh]

Hi,

Could you try to use the HardFault handling library to determine the cause of the Hardfault? As my colleague explained in this thread. 

-Amanda H.

[prithvi25]

I went through that thread.
so after "return (p_fs->p_api)->erase(p_fs, page_addr, len, p_context);" in nrf_fstorage_erase() it shows BusFault.

So what should I do next?

[prithvi25]

And if I continue execution and then pause it (in Debug mode), it goes to HardFault_Handler

[Amanda Hsieh]

Hi, 

Unfortunately, 0x978 is the HardFault handler of the MBR. The HardFault handler of the MBR will invoke the HardFault handler at 0x2635E, which in turn should invoke the HardFault handler of the application. 

So this could indicate that the bootloader is jumping to an address that is not the reset handler of the application, but to a random address, which triggers a HardFault. It is difficult to say what the cause is without being able to step through the code myself. 

Could you provide the debug log with hardfault?  Please see Vidar's comments in this post on how to do that.

Which SDK/SoftDevice are you using?

Can you take a look at this page on StackOverflow?

Are you running the APP timer with a higher IRQ priority than the SoftDevice?

What is your setting of RAM_PH_START?

Please also see this post that might help.

-Amanda H.

[prithvi25]

RAM_START=0x20002a98

No, the APP timer does not have a higher IRQ priority than the SoftDevice.

using s140_nrf52_6.1.0_softdevice (SOFTDEVICE).

Not able to generate debug log with hardfault.

[Amanda Hsieh]

Hi, 

You could check the value of the  (p_fs->p_api)->erase function pointer to see if it's in a valid range and try to single step in debug mode to see if the program goes into the backend code or directly to the hardfault.

I have seen some cases where the function pointer is not initialized correctly because of invalid project settings. 

Which page are you erasing?

-Amanda H.

[prithvi25]

So in the 3rd image after "blx r4", in the next step, it goes to some random location, shown below

and after that, it goes to HardFault Handler

Here is the Section Placement Macros

And initialisation

[Amanda Hsieh]

Hi, 

I'm not sure. It would be very helpful if we could reproduce it. Would you like to share the project with us? I can make the case private. 

Is fstorage_erase() called from an interrupt?

The SD APIs cannot be called from an interrupt with higher priority than the SV itself

https://devzone.nordicsemi.com/f/nordic-q-a/32684/hardfault-on-an-sd_ble_gatts_hvx-call-in-sdk-14-2-0

 

-Amanda H.