FDS breaks RTT

RE: FDS breaks RTT

JVKran — Fri, 11 Dec 2020 15:27:49 GMT

Hi Einar,

I'm sorry to have wasted your time. Turns out, I made a very silly mistake with the JLinkRTTClient... I've added it as a target in the makefile so I can run 'make terminal' to have the output in VS code. However, I was using the wrong command to setup RTT communication.

I used

JLink -device NRF52 -speed 4000 -if SWD -AutoConnect 1

while I should have used

JLink -device NRF52840_XXAA -speed 4000 -if SWD -AutoConnect 1

I can't believe it actually worked all this time! I have probably been developing and using the terminal like this for nearly three months already. Oh well, it's at least working now. FDS was just the unlucky addition that overflowed the bucket...

Anyway, thanks for your help and time.

Kind regards,

Jochem

RE: FDS breaks RTT

JVKran — Fri, 11 Dec 2020 14:33:59 GMT

Hi Einar,

Well, I've set breakpoints at all lines "NRF_LOG_BACKEND_SECTION_NAME" occurs, but none of them triggers. Neither with the source files included nor without them.

The structs contain the same values. Only the location of the timestamp function changes. The debugger also shows that the same piece of code is executed.

Could it be something else than the section variables? The program is quite large with I2S, I2C, SPI, SD card, beacon scanning, mesh participation, etc. Would've thought that if it'd had to do something with section variables, I'd have already encountered major problems right?

Kind regards,

Jochem

RE: FDS breaks RTT

JVKran — Fri, 11 Dec 2020 13:21:11 GMT

Hi Einar,

Thanks for the quick reply! I'll look into it and keep you updated.

Kind regards,

Jochem

RE: FDS breaks RTT

Einar Thorsrud — Fri, 11 Dec 2020 13:16:44 GMT

Hi Jochem,

There should not be any link between RTT logging and fstorage/FDS. However, both the logger module and fstorage rely on section variables, and that does not work well out of the box with C++, particularly with GCC. See this post. I suspect that perhaps the log backend is never registered properly by the linker.

Can you check if the log backend (NRF_LOG_BACKEND_SECTION_NAME) is iterated over properly in components/libraries/log/src/nrf_log_frontend.c and compare to see the difference with and without FDS/fstorage, and that the data in the struct is correct?

Einar