Zephyr/NCS too large memory footprint

RE: Zephyr/NCS too large memory footprint

Turbo J — Tue, 20 Jan 2026 19:45:03 GMT

Check generated config, you might have CONFIG_BT_CENTRAL turned on by accident (or default). The combined BTLE softdevice is a lot bigger than peripherial only.

RE: Zephyr/NCS too large memory footprint

David M. M. — Tue, 20 Jan 2026 16:12:23 GMT

The last version of NCS 3.2.1, increase again the footprint of Zephyr. It seems that some features may not fit some nrf52 chips. Unfortunately, Nordic does not seem to encourage the use of the HAL (NRFX) which could potentially be a solution.

RE: Zephyr/NCS too large memory footprint

Sigurd — Fri, 15 Nov 2024 16:02:13 GMT

[quote user="icedfluid"]Is there really no way to achieve a substantial reduction in the footprint of Zephyr/NCS and the libraries used during the build process?[/quote]

Depends on your application. Use e.g. the Memory report UI to identity what is taking a lot of flash. https://docs.nordicsemi.com/bundle/nrf-connect-vscode/page/reference/ui_memory_report.html , Also, e.g. the "No paths" at 120.12 kB should be investigated to see if there is something there you can reduce.

RE: Zephyr/NCS too large memory footprint

icedfluid — Fri, 15 Nov 2024 13:53:31 GMT

Hi Sigurd

I’ve already tried many options from prj_minimal.conf. The most recent ones I tested reduced the footprint by only a few hundred bytes. Unfortunately, that’s not a significant improvement and, in my opinion, clearly not enough.

Even with all printk and logs disabled, the full firmware archive occupies 86% of a single flash slot. With debug logs enabled, it jumps to 96%.

Is there really no way to achieve a substantial reduction in the footprint of Zephyr/NCS and the libraries used during the build process?

RE: Zephyr/NCS too large memory footprint

Sigurd — Fri, 15 Nov 2024 11:46:42 GMT

Hi!

I recommend having a look at this guide on Memory footprint optimization:

https://docs.nordicsemi.com/bundle/ncs-2.6.2/page/nrf/test_and_optimize/optimizing/memory.html

Also, as mentioned in the guide, for reference, you can find minimal footprint configurations of the Bluetooth: Peripheral LBS sample in nrf/samples/bluetooth/peripheral_lbs/prj_minimal.conf

https://github.com/nrfconnect/sdk-nrf/blob/v2.6.2/samples/bluetooth/peripheral_lbs/prj_minimal.conf