52840dk Segger debug exception when using softdevices.

RE: 52840dk Segger debug exception when using softdevices.

Edvin — Wed, 05 Feb 2020 11:54:21 GMT

I didn't notice before now that you are using Mesh. I am not sure what DFU example you refer to, or what bootloader you are pointing to (mesh/"normal"). I believe it is better that you follow it up in the ticket you already have. I will ask the engineer that is assigned to that ticket to have a look at it.

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Wed, 05 Feb 2020 08:30:15 GMT

Yes, I got the app note about it from Segger, definitely will try it, but at the moment it is a second priority. I need to resolve the dfu examples issues.

Posted some questions which could help forward, but still not clear why dfu example overwrites bootloader at 0x1f000, why there is no bootloader for 840, if I load bootloader with nrfjprog, how is the UICR getting set.

In parallel building some framework to comm with serial, cannot use Python on my controller - Coldfire on Netburner module.

Could you see the case 243613? There is no reply at all for 3 days ...

Piotr

RE: 52840dk Segger debug exception when using softdevices.

Edvin — Wed, 05 Feb 2020 08:19:40 GMT

Your application will not work if the softdevice asserts. The connection will break. Either way, you should just try to not start advertising or connecting if you want to step in your code. If that isn't viable, then you must use the logging tools.

There is something called Monitor Mode Debugging. I have not tested this myself, but that may be something you want to look into if you need to step through parts of your code. It is a bit of work to get it up and running, but if you need it, I guess you can try.

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Tue, 04 Feb 2020 15:23:59 GMT

Is there a way to disable this hardfault handler? I will have a lot of debugging of non radio related code - our app interface, and restarting app after each breakpoint would be painful. I need to implement comm with a host over UART, and would like to do it with softdevice in place. Other option would be creating an app without softdevice, but this will take some time.

Piotr

RE: 52840dk Segger debug exception when using softdevices.

Edvin — Tue, 04 Feb 2020 14:55:53 GMT

It is not a debug error. It is the hardfault handler for the nRF caused by the softdevice missing the events. There is a logging module in the SDK which is a handy tool. You see a lot of the NRF_LOG_INFO. Depending on whether you use the RTT or the UART backend (selected in sdk_config.h) it will be output on either the RTT or the UART.

If you are using Segger Embedded Studio (SES), I can recommend using the RTT backend, and it will show when you are debugging. If you are using SES and RTT, please set NRF_FPRINTF_FLAG_AUTOMATIC_CR_ON_LF_ENABLED to 0 (also in sdk_config.h).

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Tue, 04 Feb 2020 14:15:19 GMT

The issue of the JTAG debugger stopping at 0xa60 after continue from suspend or breakpoint.

It happens on both 840dk, and 832dk. I agree with you that it is caused by not serviced event in the soft device.

I am using segger, but the gui does not matter, this is in the rtl of the debugger on silicon.

But if you say, this is a normal operation procedure, to restart the app after each breakpoint, probably this has to be like that. I need to implement some realtime debugging support through the UART or sth like that.

Piotr

RE: 52840dk Segger debug exception when using softdevices.

Edvin — Tue, 04 Feb 2020 14:01:58 GMT

What issue do you refer to? And what debugger do you use? Is it the nRF52840 DK?

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Tue, 04 Feb 2020 13:25:15 GMT

OK, case closed, understand.

But it looks to me like there is a silicon issue, related to the debugger RTL.

Could you tell me, if this is described somewhere in the docs?

Piotr

RE: 52840dk Segger debug exception when using softdevices.

Edvin — Mon, 03 Feb 2020 15:19:17 GMT

Hello,

If you break during the debug session after the SoftDevice has started, it will assert later. This is because the SoftDevice will miss some time critical events where it was supposed to use the radio. So you can use breakpoints to see what's happening for a few steps, but when you step out of that function (or possibly before) then the softdevice will assert.

What you should do is to use the breakpoints to check certain things that you want to check, and then you must reset the application.

Best regards,

Edvin

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Mon, 03 Feb 2020 12:54:14 GMT

For reference, here how I have unzipped SDKs on my HD, and serial example is in its original "mesh sdk" location:

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Mon, 03 Feb 2020 11:23:45 GMT

For reference I am sending the current binaries I am using for the project "serial" from the mesh sdk.

If you set the breakpoint on main.c:155, run,, first src stepover is OK, second stepover generates the exception.

I am using Segger 4.42, with latest firmware on the 840DK

Calls to my code should be disabled in this project.

I will try 832DK with older firmware.

devzone.nordicsemi.com/.../serial.zip

RE: 52840dk Segger debug exception when using softdevices.

pkoenig — Mon, 03 Feb 2020 11:10:08 GMT

Igor, sorry, it implies latest versions (released to the web)

The 840DK ver 1.1.0

Included two screen shots: after stopping on breakpoint, and after continue. Do not know if you could see graphics in the post, so adding those two pics as one zip.

If I do single step in asm mode, it debugs correctly, but stepover in source is causing this exception.

If you step in asm mode, you just issue single step to the debug logic on the core, with source stepover, most likely they insert temp break at the step target address, then run. Any run is causing probably this exception - possibly caused by pending interrupts in the exec pipeline.

Do you know if there is a way to show low level debugger operations on the JTAG interface?

Thx, Piotr

devzone.nordicsemi.com/.../Downloads.zip

RE: 52840dk Segger debug exception when using softdevices.

Igor — Mon, 03 Feb 2020 10:30:25 GMT

Can you please post a stack trace.
It would be also very helpful, if you would mention your SDK & SD version.