NCS startup time is too long, reaching 1684ms

RE: NCS startup time is too long, reaching 1684ms

Håkon Alseth — Fri, 17 Oct 2025 14:13:45 GMT

Hi,

You can verify what signature type is set by going into build/mcuboot/zephyr/.config and checking. It is "CONFIG_BOOT_SIGNATURE_TYPE_ECDSA_P256" on my side.

[quote user="Glory"]SB_CONFIG_BOOT_SIGNATURE_TYPE_NONE[/quote]

This will skip verification, but do a full hash of the image:

https://docs.nordicsemi.com/bundle/ncs-latest/page/kconfig/index.html#SB_CONFIG_BOOT_SIGNATURE_TYPE_NONE

Are you sure you want "NONE" selected, as compared to using the default signature check?

https://docs.nordicsemi.com/bundle/ncs-latest/page/kconfig/index.html#SB_CONFIG_BOOT_SIGNATURE_TYPE_ECDSA_P256

Kind regards,

Håkon

RE: NCS startup time is too long, reaching 1684ms

Quay — Fri, 17 Oct 2025 13:19:06 GMT

Hi Håkon,

Yes,unsetting SB_CONFIG_BOOT_SIGNATURE_TYPE_NONE indeed reduced the time to 135ms, which is quite significant. However, this prevents the firmware from being verified, potentially leading to irreversible actions. Is it possible to implement verification only during the first firmware transfer after an OTA update?

regards

RE: NCS startup time is too long, reaching 1684ms

Håkon Alseth — Fri, 17 Oct 2025 13:03:32 GMT

Hi,

Try unsetting SB_CONFIG_BOOT_SIGNATURE_TYPE_NONE in sysbuild.conf.

Kind regards,

Håkon

RE: NCS startup time is too long, reaching 1684ms

Quay — Fri, 17 Oct 2025 02:23:31 GMT

Hi Håkon,

Yes, after setting up prj.conf and mcuboot.conf, I observed the time reduced to 745ms.

# disable CC3XX
CONFIG_HW_CC3XX=n
CONFIG_ENTROPY_CC3XX=n
CONFIG_ENTROPY_NRF5_RNG=y
CONFIG_CC3XX_BACKEND=n

How did you achieve 140ms? Is there any other configuration I haven't set?

regards,

RE: NCS startup time is too long, reaching 1684ms

Håkon Alseth — Thu, 16 Oct 2025 15:14:07 GMT

Hi,

Yes, I also still see a significant delay.

Could you disable the CC3xx in addition?

Here's how to set that up: RE: High Current 400ms+ Startup Delay BLE Beacon Using RC Oscillator

Note that you need this in both prj.conf and mcuboot.conf.

I got it down to 140 ms from cold-boot:

Kind regards,

Håkon

RE: NCS startup time is too long, reaching 1684ms

Quay — Thu, 16 Oct 2025 12:58:23 GMT

Hi Håkon,

Thank you for your prompt reply.I added in both prj.conf and mcuboot.conf

CONFIG_LOG=n
CONFIG_SERIAL=n
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n
CONFIG_CLOCK_CONTROL_NRF_K32SRC_250PPM=y

The startup time has been reduced to 1195 milliseconds, but it's still far from my target of 100 milliseconds.

RE: NCS startup time is too long, reaching 1684ms

Håkon Alseth — Thu, 16 Oct 2025 11:55:52 GMT

Hi,

Have you tried to disable SERIAL in all images, including mcuboot, and then check the boot-up time?

You can also try to switch the 32kHz clock source to internal RC:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

Kind regards,

Håkon

RE: NCS startup time is too long, reaching 1684ms

Quay — Thu, 16 Oct 2025 08:39:23 GMT

Supplement: I'd like to know what causes this long execution time? Is there any information to understand the execution process before the Main function?