sysbuild + partition manager + mcuboot + external flash

RE: sysbuild + partition manager + mcuboot + external flash

Amanda Hsieh — Wed, 09 Jul 2025 20:24:24 GMT

Happy to hear that. 🙂

RE: sysbuild + partition manager + mcuboot + external flash

rerickson — Wed, 09 Jul 2025 19:32:12 GMT

Thank you, that was very helpful!

1. I fixed my boot loop issue. It had to do with board file issues. I synced my board files with the nrf54l15dk board files in NCS 3.0.0 and it solved the boot loop.

2. Based on your feedback I was missing:

CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE=4096

Now everything looks good:

[00:00:00.003,449] <inf> spi_nor: mx25r6435f@0: SFDP v 1.6 AP ff with 3 PH
[00:00:00.010,654] <inf> spi_nor: PH0: ff00 rev 1.6: 16 DW @ 30
[00:00:00.017,088] <inf> spi_nor: mx25r6435f@0: 8 MiBy flash
[00:00:00.023,078] <inf> spi_nor: PH1: ffc2 rev 1.0: 4 DW @ 110
[00:00:00.031,606] <inf> mcuboot: Starting bootloader
[00:00:00.037,479] <dbg> mcuboot: boot_slots_compatible: Non-optimal sector distribution, slot0 has 354 usable sectors (362 assigned) but slot1 has 362 assigned
[00:00:00.052,177] <dbg> mcuboot: swap_write_block_size_check: Discrepancy, slot1 expected write block size: 16, actual: 1
[00:00:00.063,556] <inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
[00:00:00.073,571] <inf> mcuboot: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
[00:00:00.083,531] <inf> mcuboot: Boot source: none
[00:00:00.089,089] <inf> mcuboot: Image index: 0, Swap type: none
[00:00:00.194,900] <inf> mcuboot: Bootloader chainload address offset: 0x13000
[00:00:00.202,447] <inf> mcuboot: Image version: v0.0.0
[00:00:00.254,553] <inf> main: Canvas Zephyr Firmware v2.1.99+1752088601 [bl54l15_dvk]

RE: sysbuild + partition manager + mcuboot + external flash

Amanda Hsieh — Wed, 09 Jul 2025 18:49:22 GMT

Hi,

[quote user=""]

I am testing this with nrf54L15 + 8 MB SPI flash on the DVK.

This same issue occurs with nrf52840 + 2MB QSPI flash.

[/quote]

The settings to use the external flash memory via SPI or QSPI are different. Please take a look at this course https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/topic/exercise-3-dfu-with-external-flash/ .

This sample zephyr/samples/subsys/mgmt/mcumgr/smp_svr can demonstrate on how to set secondary on the nRF54L15DK external flash. You can build with the extra_args:
- OVERLAY_CONFIG="overlay-bt.conf"
- DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_ext_flash.overlay"
- mcuboot_CONF_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_ext_flash.conf"
- mcuboot_EXTRA_DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_ext_flash.overlay"
- SB_CONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK=y
- SB_CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

-Amanda H.

RE: sysbuild + partition manager + mcuboot + external flash

rerickson — Tue, 08 Jul 2025 20:27:50 GMT

Now I am experiencing a boot loop. Any ideas of where to look? The debugger isn't showing anything useful...

[00:02:48.723,857] <inf> mcuboot: Starting bootloader
[00:02:48.724,179] <wrn> mcuboot: Cannot upgrade: not a compatible amount of sectors
[00:02:48.833,905] <inf> mcuboot: Starting bootloader
[00:02:48.834,227] <wrn> mcuboot: Cannot upgrade: not a compatible amount of sectors

RE: sysbuild + partition manager + mcuboot + external flash

rerickson — Tue, 08 Jul 2025 15:42:07 GMT

I believe I have solved the issue. BOTH of the following need to be set at the sysbuild level:

SB_CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y
SB_CONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK=y