Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

AHaug — Thu, 22 May 2025 13:19:07 GMT

Hi,

FYI, relaying the PR https://github.com/nrfconnect/sdk-nrf/pull/22454

Kind regards,
Andreas

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

Nick Ewalt — Fri, 25 Apr 2025 16:39:51 GMT

The issue still persists in NCS. I have a local patch to fix it.

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

AHaug — Fri, 25 Apr 2025 12:44:25 GMT

Hi,

Apologies for the long wait.

I've picked up the case, could you verify if the issue still persists on your end or if you've been able to resolve it since our last reply?

Kind regards,
Andreas

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

Nick Ewalt — Thu, 13 Mar 2025 23:55:15 GMT

The sample will boot as-is, here is the output with CONFIG_MCUBOOT_LOG_LEVEL_INF=y:

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
Attempting to boot slot 0.
Attempting to boot from address 0x8200.
I: Trying to get Firmware version
I: Verifying signature against key 0.
I: Hash: 0x41...4a
I: Firmware signature verified.
Firmware version 1
I: Setting monotonic counter (version: 1, slot: 0)
*** Booting MCUboot v2.1.0-dev-12e5ee106034 ***
*** Using nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
I: Starting bootloader
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
I: Image index: 0, Swap type: none
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
I: Image index: 1, Swap type: none
I: Bootloader chainload address offset: 0x28000
�*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
Address of sample 0x30000
Hello sysbuild with mcuboot! nrf9160dk

However that doesn't mean it is working correctly. Without the headers it won't be able to swap or revert updates. Additionally it will fail to boot with CONFIG_BOOT_VALIDATE_SLOT0=n (which is how I noticed this originally in my application). Here are the logs:

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
Attempting to boot slot 0.
Attempting to boot from address 0x8200.
I: Trying to get Firmware version
I: Verifying signature against key 0.
I: Hash: 0x41...4a
I: Firmware signature verified.
Firmware version 1
I: Setting monotonic counter (version: 1, slot: 0)
*** Booting MCUboot v2.1.0-dev-12e5ee106034 ***
*** Using nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
I: Starting bootloader
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
I: Image index: 0, Swap type: none
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
I: Image index: 1, Swap type: none
E:   bad image magic 0xffffffff; Image=1
E: Unable to find bootable image

This happens because this code path is missing the conditional on image_validated_by_nsib as seen here. Note that the comment immediately above that code is wrong: image 1 primary is certainly not the currently executing mcuboot image, and therefore has not been validated by NSIB.

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

Edvin — Thu, 13 Mar 2025 14:08:09 GMT

[quote user="Nick Ewalt"]

BUILD/signed_by_b0_mcuboot.hex (<-- wrong as described above)
BUILD/signed_by_b0_s1_image.hex (<-- wrong as described above)

[/quote]

I am sure you have described it, but can we simplify this issue. What are the symptoms that you are seeing with this approach? When flashing it with the FW built in v2.9.0. Does it work? Do you see any logs that are saying that something is wrong?

Best regards,

Edvin

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

Nick Ewalt — Wed, 12 Mar 2025 21:38:36 GMT

No, my application is fine. I confirmed that I can reproduce the issue on a pristine NCS 2.9.0 using the Zephyr sample applications and the nrf9160dk board.

Let's use zephyr/samples/sysbuild/with_mcuboot as an example. If I add just SB_CONFIG_SECURE_BOOT_APPCORE=y to its sysbuild.conf I get the exact same behavior as described above.

This is my build command:

west build . -b nrf9160dk/nrf9160/ns --sysbuild -DZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb -DGNUARMEMB_TOOLCHAIN_PATH=$PREBUILT_PATH/gcc-arm-none-eabi-13.2.rel1/linux/

Here is the partition manager report.

  flash_primary (0x100000 - 1024kB):
+--------------------------------------------------+
+---0x0: b0_container (0x8000 - 32kB)--------------+
| 0x0: b0 (0x8000 - 32kB)                          |
+---0x8000: s0 (0xc000 - 48kB)---------------------+
| 0x8000: s0_pad (0x200 - 512B)                    |
+---0x8200: s0_image (0xbe00 - 47kB)---------------+
| 0x8200: mcuboot (0xbe00 - 47kB)                  |
+--------------------------------------------------+
| 0x14000: EMPTY_0 (0x4000 - 16kB)                 |
+---0x18000: s1 (0xc000 - 48kB)--------------------+
| 0x18000: s1_pad (0x200 - 512B)                   |
| 0x18200: s1_image (0xbe00 - 47kB)                |
+--------------------------------------------------+
| 0x24000: EMPTY_1 (0x4000 - 16kB)                 |
+---0x28000: mcuboot_primary (0x68000 - 416kB)-----+
+---0x28000: tfm_secure (0x8000 - 32kB)------------+
| 0x28000: mcuboot_pad (0x200 - 512B)              |
+---0x28200: app_image (0x67e00 - 415kB)-----------+
+---0x28200: mcuboot_primary_app (0x67e00 - 415kB)-+
| 0x28200: tfm (0x7e00 - 31kB)                     |
+---0x30000: tfm_nonsecure (0x60000 - 384kB)-------+
| 0x30000: app (0x60000 - 384kB)                   |
+--------------------------------------------------+
| 0x90000: mcuboot_secondary (0x68000 - 416kB)     |
| 0xf8000: EMPTY_2 (0x8000 - 32kB)                 |
+--------------------------------------------------+

The merged.hex consists of the following files:

BUILD/app_provision.hex
BUILD/b0_container.hex
BUILD/s0_image.hex
BUILD/s0.hex
BUILD/s1.hex
BUILD/b0/zephyr/zephyr.hex
BUILD/signed_by_b0_mcuboot.hex (<-- wrong as described above)
BUILD/signed_by_b0_s1_image.hex (<-- wrong as described above)
BUILD/with_mcuboot/zephyr/zephyr.signed.hex

The missing mcuboot headers (and trailers) can also clearly be seen in the merged.hex hex dump:

$ srec_info BUILD/merged.hex -Intel
Format: Intel Hexadecimal (MCS-86)
Data:   000000 - 0002EB
        0002F0 - 0050C7
        0050D0 - 005CB5
        008200 - 00E097
        00E0A0 - 00EA9D
        00EAA0 - 00EB4F
        018200 - 01E097
        01E0A0 - 01EA9D
        01EAA0 - 01EB4F
        028000 - 03822D
        FF8130 - FF817F

$ srec_info BUILD/signed_by_b0_mcuboot.hex -Intel
Format: Intel Hexadecimal (MCS-86)
Data:   8200 - E097
        E0A0 - EA9D
        EAA0 - EB4F

$ srec_info BUILD/signed_by_mcuboot_and_b0_mcuboot.hex -Intel
Format: Intel Hexadecimal (MCS-86)
Data:   8000 - EBE6

RE: Sysbuild doesn't include MCUBoot headers in merged.hex when using upgradeable bootloader

Edvin — Tue, 11 Mar 2025 08:23:11 GMT

Hello,

Sorry for the late reply.

To me this sounds like the application is not properly ported for sysbuild, and that the bootloader is not properly included.

Please have a look at the migration notes for NCS v2.7.0:

https://docs.nordicsemi.com/bundle/ncs-2.9.0/page/nrf/releases_and_maturity/migration_guides.html

Also, as an introduction to the sysbuild, I really recommend going through the nRF Connect SDK Intermediate course on DevAcademy. Particularly Lesson 8 is focused on Sysbuild and multi-image builds:

https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-8-sysbuild/

Best regards,

Edvin