Flash overflow when simple overlay is added

[Erik Hougaard]

Hi,

I am developing a LWM2M/OT solution including mcuboot on the nRF52840 chip. The solution is working well on the nRF52840 DK, but when building it for our custom board I need to make a few adjustments to the devicetree. Just switching a few pins, but whenever I include this overlay (even on the DK build configuration) the program size seems to grow around 500 kB, and I get an overflow message:

&i2c0_default {
    group1 {
        psels = <NRF_PSEL(TWIM_SDA, 0, 28)>,
            <NRF_PSEL(TWIM_SCL, 0, 29)>;
    };
};

&led0 {
    gpios = <&gpio0 26 GPIO_ACTIVE_LOW>;
    label = "Green LED 0";
};

The error message (sorry, I was unable to insert it as a code block for some odd reason):

[912/931] Linking CXX static library zephyr\kernel\libkernel.a
[913/931] Linking CXX executable zephyr\zephyr_pre0.elf
FAILED: zephyr/zephyr_pre0.elf zephyr/zephyr_pre0.map
cmd.exe /C "cd . && C:\NordicSemi\toolchains\v2.1.0\opt\zephyr-sdk\arm-zephyr-eabi\bin\arm-zephyr-eabi-g++.exe @CMakeFiles\zephyr_pre0.rsp -o zephyr\zephyr_pre0.elf && cmd.exe /C "cd /D C:\test\FarrowLinkSC20221102\build\zephyr && C:\NordicSemi\toolchains\v2.1.0\opt\bin\cmake.exe -E echo ""
c:/nordicsemi/toolchains/v2.1.0/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.3.0/../../../../arm-zephyr-eabi/bin/ld.exe: zephyr\zephyr_pre0.elf section `text' will not fit in region `FLASH'
c:/nordicsemi/toolchains/v2.1.0/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.3.0/../../../../arm-zephyr-eabi/bin/ld.exe: region `FLASH' overflowed by 274692 bytes
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: 'c:\NordicSemi\toolchains\v2.1.0\opt\bin\cmake.EXE' --build 'c:\test\FarrowLinkSC20221102\build'
The terminal process terminated with exit code: 1.

I am using nRF Connect SDK 2.1.0 and tried with 2.2.0 too. OS is Windows 10.

Adding the overlay to a simple hello-world example does not result in increased size.

Any help is greatly appreciated,

Erik

[Håkon Alseth]

Hi,

 

The solution is working well on the nRF52840 DK, but when building it for our custom board I need to make a few adjustments to the devicetree.

Does this also include a board change? Ie. from nrf52840dk_nrf52840 to my_custom_board_nrf52840 ?

 

Could you share the default configuration, or the generated configuration diff between "nrf52840dk_nrf52840" and your custom board?

The configuration file is in build-folder\zephyr\.config

 

Kind regards,

Håkon

[Erik Hougaard]

Hi,

No board change is made. I use the nrf52840dk_nrf52840 and only add one CMAKE argument: -DDTC_OVERLAY_FILE=custom.overlay

These are the differences between the two .config files:

Best regards,

Erik

[Håkon Alseth]

Hi,

 

The first scenario looks to enable external flash for the secondary slot, while the second scenario will use internal flash (ie. ~500 kB per image).

I highly suspect that you have a boards/nrf52840dk_nrf52840.overlay file present?

If you need to load several .overlay files, you should either use list(APPEND DTC_OVERLAY_FILE file.overlay) in CMakeLists.txt or explicitly define all when calling cmake.

See this thread for detailed info: https://github.com/zephyrproject-rtos/zephyr/issues/27548#issuecomment-697313071

 

Kind regards,

Håkon

[Erik Hougaard]

Thanks Håkon,

You are absolutely right, there was a boards/nrf52840dk_nrf52840.overlay file present. I have made sure to include that one too, and things work just great.

Thank you for the quick solution.

Best regards,

Erik

[Håkon Alseth]

Hi Erik,

 

Glad to hear that the issue was solved! Hope you have a wonderful day!

 

Cheers,

Håkon