Sysbuild and MCUboot porting build error

[Zoptune]

Hi,

I am working on a project with an nrf9160 on a custom board that I first developed with NCS v2.6.1.

I am trying to upgrade to latest NCS v2.9.1 but I am facing an issue a link stage.

I moved my custom board definition to HW model v2 without any (visible) issue and I want to move the build system to sysbuild and use MCUboot as immutable first-stage bootloader.
If followed the different guides and looked at how it has been done in the existing samples in NCS repository but I am facing an issue at link time where it says that a section does not fit in FLASH region.

[544/549] Linking C executable zephyr/zephyr_pre0.elf
...
/home/alexandre/ncs/toolchains/b77d8c1312/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd: zephyr/zephyr_pre0.elf section `text' will not fit in region `FLASH'
/home/alexandre/ncs/toolchains/b77d8c1312/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd: region `FLASH' overflowed by 154696 bytes
collect2: error: ld returned 1 exit status

Here is the result of 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 (0x6000 - 24kB)                 |
+---0xfe000: nonsecure_storage (0x2000 - 8kB)------+
| 0xfe000: settings_storage (0x2000 - 8kB)         |
+--------------------------------------------------+

I don't know where to start to investigate this issue. Also I am not sure to fully understand what are the different image built in non-secure mode (b0, s0, s1, ...).

Regards

Alexandre

[Vidar Berg]

Hello,

Please check what the size of the main app was in your  project based on v2.6.1 and also create a partition manager report of that project for comparison. The NSIB bootloader (B0) and the s0 and s1 slots are included when you enable SB_CONFIG_SECURE_BOOT_APPCORE and it results in less available space for the application slots.

Best regards,

Vidar

[Zoptune]

Hello and thanks for your answer !

Unfortunately adding version 2.9.1 broke my 2.6.1 installation.
I get a cmake error regarding python when trying to build:

-- CMake version: 3.21.0
-- Using NCS Toolchain 2.8.20241119.788085347090 for building. (/home/alexandre/ncs/toolchains/b77d8c1312/cmake)
CMake Error at /home/alexandre/ncs/toolchains/2be090971e/usr/local/share/cmake-3.21/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find Python3 (missing: Interpreter) (Required is at least version
  "3.8")

      Reason given by package: 
          Interpreter: Cannot run the interpreter "/home/alexandre/ncs/toolchains/b77d8c1312/usr/local/bin/python3"

[Zoptune]

Sorry for the delay,

I tried to specify the toolchain to use because I have both NCS version 2.6.1 and 2.9.1 installed but it does not work. I end up removing toolchain for 2.9.1 but I still have the same issue with toolchain 2.6:

-- CMake version: 3.21.0
-- Using NCS Toolchain 2.6.20240304.188451165982 for building. (/home/alexandre/ncs/toolchains/2be090971e/cmake)
CMake Error at /home/alexandre/ncs/toolchains/2be090971e/usr/local/share/cmake-3.21/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find Python3 (missing: Interpreter) (Required is at least version
  "3.8")

      Reason given by package: 
          Interpreter: Cannot run the interpreter "/home/alexandre/ncs/toolchains/b77d8c1312/usr/local/bin/python3"

It still tries to run interpreter in toolchain b77d8c1312 which correspond to toolchain for 2.9.1 (I think).

I will try to clean my env and reinstall it.

[Vidar Berg]

I assume this path does not exist anymore since you have removed the toolcain: /home/alexandre/ncs/toolchains/b77d8c1312/usr/local/bin/python3? Either way, I think you should be able to build the previous project with the new toolchain.

[Zoptune]

Ok finally was able to recreate both 2.6.1 and 2.9.1 working environment.

The problem is the one described in the error (ofc), my image is too big.

- With NCS v2.6.1, I was using nrf immutable bootlader with a single app section (~984kB).

  flash_primary (0x100000 - 1024kB): 
+---------------------------------------------+
+---0x0: tfm_secure (0x8000 - 32kB)-----------+
| 0x0: tfm (0x8000 - 32kB)                    |
+---0x8000: tfm_nonsecure (0xf6000 - 984kB)---+
| 0x8000: app (0xf6000 - 984kB)               |
+---0xfe000: nonsecure_storage (0x2000 - 8kB)-+
| 0xfe000: settings_storage (0x2000 - 8kB)    |
+---------------------------------------------+

  otp (0x2f4 - 756B): 
+------------------------------+
| 0xff8108: otp (0x2f4 - 756B) |
+------------------------------+

  sram_primary (0x40000 - 256kB): 
+--------------------------------------------------+
+---0x20000000: sram_secure (0x8000 - 32kB)--------+
| 0x20000000: tfm_sram (0x8000 - 32kB)             |
+---0x20008000: sram_nonsecure (0x38000 - 224kB)---+
+---0x20008000: nrf_modem_lib_sram (0x4568 - 17kB)-+
| 0x20008000: nrf_modem_lib_ctrl (0x4e8 - 1kB)     |
| 0x200084e8: nrf_modem_lib_tx (0x2080 - 8kB)      |
| 0x2000a568: nrf_modem_lib_rx (0x2000 - 8kB)      |
+--------------------------------------------------+
| 0x2000c568: sram_primary (0x33a98 - 206kB)       |
+--------------------------------------------------+

- With NCS v2.9.1 and mcuboot I now have 2 app section much smaller (416kB) wich is not enough for my app (~515kB).

Memory region         Used Size  Region Size  %age Used
           FLASH:      528312 B       984 KB     52.43%
             RAM:      120920 B     211608 B     57.14%
        IDT_LIST:          0 GB        32 KB      0.00%

I will try to reduce my app size but I would like to first use mcuboot in single app image mode in order to get back to a single 900kB section and later I will add an external flash to switch to dual image mode.

What config do I need to add (and where) to achieve single image mode this (using sysbuild) and where do I define the slot size ? Because of the SPM, defining it in DTS does not work right ?

Regards,

[Vidar Berg]

Zoptune said:

- With NCS v2.6.1, I was using nrf immutable bootlader with a single app section (~984kB).

The memory report does not show any bootloaders, only TF-M and app. If you want to support DFU with only one bootloader you need to select MCUBoot as your immutable bootloader and make sure you are not enabling SB_CONFIG_SECURE_BOOT_APPCORE in your project configuration.

• Migrating from multi-image builds to sysbuild

[Zoptune]

Yes you are right my bad.

Now that that I explicitly added SB_CONFIG_SECURE_BOOT_APPCORE=n I am getting a nicer partition report

  flash_primary (0x100000 - 1024kB): 
+--------------------------------------------------+
| 0x0: mcuboot (0xc000 - 48kB)                     |
| 0xc000: EMPTY_0 (0x4000 - 16kB)                  |
+---0x10000: mcuboot_primary (0x70000 - 448kB)-----+
+---0x10000: tfm_secure (0x8000 - 32kB)------------+
| 0x10000: mcuboot_pad (0x200 - 512B)              |
+---0x10200: mcuboot_primary_app (0x6fe00 - 447kB)-+
| 0x10200: tfm (0x7e00 - 31kB)                     |
+---0x18000: tfm_nonsecure (0x68000 - 416kB)-------+
| 0x18000: app (0x68000 - 416kB)                   |
+--------------------------------------------------+
| 0x80000: mcuboot_secondary (0x70000 - 448kB)     |
| 0xf0000: EMPTY_1 (0xe000 - 56kB)                 |
+---0xfe000: nonsecure_storage (0x2000 - 8kB)------+
| 0xfe000: settings_storage (0x2000 - 8kB)         |
+--------------------------------------------------+

  otp (0x2f4 - 756B): 
+------------------------------+
| 0xff8108: otp (0x2f4 - 756B) |
+------------------------------+

  sram_primary (0x40000 - 256kB): 
+--------------------------------------------------+
+---0x20000000: mcuboot_sram (0x8000 - 32kB)-------+
+---0x20000000: sram_secure (0x8000 - 32kB)--------+
| 0x20000000: tfm_sram (0x8000 - 32kB)             |
+---0x20008000: sram_nonsecure (0x38000 - 224kB)---+
+---0x20008000: nrf_modem_lib_sram (0x34e8 - 13kB)-+
| 0x20008000: nrf_modem_lib_ctrl (0x4e8 - 1kB)     |
| 0x200084e8: nrf_modem_lib_tx (0x1000 - 4kB)      |
| 0x200094e8: nrf_modem_lib_rx (0x2000 - 8kB)      |
+--------------------------------------------------+
| 0x2000b4e8: sram_primary (0x34b18 - 210kB)       |
+--------------------------------------------------+

Now the problem I have is that I still have 2 "small" mcuboot partitions.

I want to have only one big mcuboot partition.

I am trying to use options like CONFIG_MCUBOOT_BOOTLOADER_MODE_SINGLE_APP or CONFIG_SINGLE_APPLICATION_SLOT but I don't know where to put them (prj.conf, sysbuild.conf, sysbuild/mcuboot/app.conf).
Or should I also modify the flash0 in the DTS ? I am a bit lost with the partition manager.

[Vidar Berg]

Single slot DFU is currently only possible with the USB or UART transport. Please have a look at this devacademy course at https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/ for more details about the DFU solution.

[Zoptune]

Thanks.

Looking at the course I realized that I was using CONFIG_MCUBOOT_BOOTLOADER_MODE_SINGLE_APP instead of SB_CONFIG_MCUBOOT_MODE_SINGLE_APP.

It works great now :)