nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Kevin Lin — Thu, 12 Feb 2026 12:04:47 GMT

Hi Vidar,

I apologize for the late reply. I was out of the office for the past few days. I have already found the problem. Thank you very much for your help.

Best regards,
Kevin

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Vidar Berg — Fri, 06 Feb 2026 09:43:00 GMT

Hi Kevin,

Thanks. This shows that the assert is being raised at this line in the bootloader: https://github.com/nrfconnect/sdk-mcuboot/blob/9b4ae4cbc9e2acf56d904647e2d5c6716d7e567d/boot/bootutil/src/loader.c#L2988. Do you have the secondary mcuboot slot placed in external flash? If so, please add CONFIG_FLASH_LOG_LEVEL_DBG=y to your project configuration and see if the driver is able to configure it as expected on startup.

Best regards,

Vidar

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Kevin Lin — Fri, 06 Feb 2026 08:53:54 GMT

Hi Vidar,

Thank you for reminding me. The debugging log is as follows:

SEGGER J-Link V8.94 - Real time terminal output
SEGGER J-Link V9.7, SN=602718579
Process: JLinkExe
*** Booting MCUboot v2.1.0-dev-9b4ae4cbc9e2 ***
*** Using nRF Connect SDK v3.1.1-e2a97fe2578a ***
*** Using Zephyr OS v4.1.99-ff8f0c579eeb ***
[0:0:0.275,268] <inf> mcuboot: Starting bootloader
[0:0:0.275,634] <dbg> mcuboot: context_boot_go: context_boot_go
ASSERTION FAIL [0] @ WEST_TOPDIR/zephyr/lib/libc/picolibc/assert.c:15
        assertion "rc == 0" failed: file "WEST_TOPDIR/bootloader/mcuboot/boot/bootutil/src/loader.c", line 2988, function: context_boot_go

Thank you.

Best regards,
Kevin

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Vidar Berg — Fri, 06 Feb 2026 06:47:17 GMT

Hi Kevin,

I was looking at the assert.c implementation for for Picolib where I assume abort() is being called:

but forgot to point out that you also need to enable asserts in this build. Is your bootloader also using Picolib? If so, please try with the following configs:

CONFIG_ASSERT=y

CONFIG_PICOLIBC_USE_MODULE=y

CONFIG_PICOLIBC_ASSERT_VERBOSE=y

Best regards,

Vidar

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Kevin Lin — Fri, 06 Feb 2026 06:21:55 GMT

Hi Vidar,

To make it easier to understand, I created a simple tree diagram of my project, as shown below:

I've tried adding this configuration to one of the files in the Kconfig section, such as mcuboot_dual_image_rtt.conf, but the result is still the same, no change at all. Or am I misunderstanding something?

Best regards,
Kevin

RE: nRF5340 SoC with nPM1304 PMIC gets stuck in bootloader

Vidar Berg — Thu, 05 Feb 2026 11:13:18 GMT

Hello Kevin,

I can't think of any relevant changes between SDK v3.0.x and v3.1.x that could explain this change in behaviour. To troubleshoot this, please try enabling CONFIG_PICOLIBC_ASSERT_VERBOSE in the bootloader build. This will hopefully tell us were the assert was raised.

Best regards,

Vidar