Section `_RTT_SECTION_NAME' can't be allocated in segment 2

[Konstantin Klitenik]

I'm getting the following notice/warning/error when building my application (nrfsdk 2.9.0 w/ sysbuild, nrf9151dk board):

/usr/local/zephyr-sdk-0.17.0/arm-zephyr-eabi/bin/arm-zephyr-eabi-objcopy: /Users/kon/Workshop/GitHub/AgX/agmuster-workspace/agmuster/build/agmuster/zephyr/st0gBFbh: section `_RTT_SECTION_NAME' can't be allocated in segment 2
LOAD: .ramfunc _RTT_SECTION_NAME bss noinit
image.py: sign the payload
image.py: sign the payload
[1/10] Performing build step for 'mcuboot'
ninja: no work to do.
[10/10] Generating ../merged.hex

We are using this config. And the error disappears if I set SEGGER_RTT to n.

CONFIG_USE_SEGGER_RTT=y

CONFIG_SHELL_BACKEND_RTT=y

CONFIG_SEGGER_RTT_BUFFER_SIZE_UP=4096

RTT seems to be working when I flash. Is this an expected message? If not, what's the proper way to address?

Thanks,

Konstantin

[Vidar Berg]

Hello,

Unfortunately, I have not been able to reproduce this objcpy error on my end. I'm using the NCS toolchain v2.9.0 (Based on Zephyr SDK v0.16.8). Have you been able to reproduce this with any of the SDK examples? 

taspon98 , are you also using the Zephyr SDK, or are you using the NCS toolchain? 

Best regards,

Vidar

[Konstantin Klitenik]

Also, we're using sysbuild, again, not sure how much that matters.

[Vidar Berg]

I thought the toolchain version might be relevant since the error was reported by objcopy, but I’m still unable to reproduce this warning using the same toolchain version. Have you managed to reproduce this warning with any of the SDK samples? Or are you able to provide a minimal version of your project that will allow me to reproduce the warning? This would make it easier to troubleshoot and determine if it really is a problem. 

Here I'm building (with sysbuild) the peripheral_uart sample which has logging over RTT enabled by default:

And not sure if it's relevant, but the _RTT_SECTION_NAME linker section appears in segment 5 in my case:

[Konstantin Klitenik]

Mine looks similar.

I don't have a minimal example but our project is just getting started and it's basically just initial setup. I can send you the repo if you let me know the best way to do that privately.

[Vidar Berg]

I think it would be easiest if you could create a new private support ticket and upload your project folder as a zip file there. Just provide me the link to the case here so I can assign it to myself.

[Vidar Berg]

I was able to reproduce the warning thanks to the project you provided, but I have not been able to determine why. So far I’ve found that the error does not occur if I configure the RTT module to not use the named linker section (_RTT_SECTION_NAME) by selecting CONFIG_SEGGER_RTT_SECTION_NONE, or if I disable CONFIG_MEMFAULT. However, I don't see why the warning goes away when memfault is disabled. I tried comparing the linker scripts and map files between these builds, but was unable to spot any relevant differences. 

 taspon98 , could you please confirm if you are using Memfault in your project as well? I don't believe the issue is directly related to memfault, but would be good if we could rule out that possibility. 

[taspon98]

I don't seem to have Memfault enabled in my project.

[Konstantin Klitenik]

I know memfault also uses the .noinit section in RAM to store reboot reasons, etc. I wonder if those 2 conflict.

[Konstantin Klitenik]

I wonder if this has something to do with conflicting .noinit sections. I know memfault creates a .noinit section for some things.

[Vidar Berg]

I did not see any changes to the placement of the .noinit when I was comparing the linker scripts. I would recommend using CONFIG_SEGGER_RTT_SECTION_NONE for now.

taspon98 , did you also have a minimal project you can share that will allow me to reproduce the warning without memfault?

[Konstantin Klitenik]

How does that impact RTT functionality?