How to confirm image installed by MCU boot

[Torsten Robitzki]

Hi,

I still try to configure Nordic-Zepyr build for a nrf5340, with a BLE stack and MCUBoot as the bootloader. The application will receive image updates over MQTT and store them in external flash memory.

According to your documentation (https://docs.nordicsemi.com/bundle/ncs-latest/page/mcuboot/design.html), MCUBOOT_SWAP_USING_MOVE seems to be the state of the art algorithm for MCUBoot to install new images. I was able to get that up and running. Next step now, is to let the newly installed firmware confirm the installation, so that the bootloader will not rollback the installation with the next reset.

It looks like the necessary modifications of the image headers or trailers are implemented in `boot_write_img_confirmed()` to confirm the new image. 

How do I have to configure my application, so that I can use this library function? The `normal` CMake way seems to be straight forward and I would just have to add the bootutil library (defined in mcuboot/boot/bootutil/CMakeLists.txt) to my application target. With Zephyr, mcuboot/boot/bootutil/zephyr/CMakeLists.txt seems to apply here and it looks like I should add CONFIG_MCUBOOT_BOOTUTIL_LIB=y to my application configuration.

According to Kconfig.mcuboot:

menuconfig MCUBOOT_BOOTUTIL_LIB
	bool "MCUboot utility library"
	help
	  Enable MCUboot utility library which implements functions
	  required by the chain-loaded application and the MCUboot.

But, that does results in build error (complaining about CONFIG_BOOT_SWAP_USING_MOVE being not set), when compiling `bootloader/mcuboot/boot/bootutil/src/bootutil_public.c`:

In file included from /Users/todi/bloomlife/zephyr-workspace/bootloader/mcuboot/boot/bootutil/zephyr/../../zephyr/include/sysflash/pm_sysflash.h:13,
                 from /Users/todi/bloomlife/zephyr-workspace/bootloader/mcuboot/boot/bootutil/zephyr/../../zephyr/include/sysflash/sysflash.h:10,
                 from /Users/todi/bloomlife/zephyr-workspace/bootloader/mcuboot/boot/bootutil/src/bootutil_public.c:43:
/Users/todi/bloomlife/zephyr-workspace/bootloader/mcuboot/boot/bootutil/zephyr/../../zephyr/include/mcuboot_config/mcuboot_config.h:75:2: error: #error "CONFIG_BOOT_SWAP_USING_MOVE not set"
   75 | #error "CONFIG_BOOT_SWAP_USING_MOVE not set"
      |  ^~~~~

Or, when I explicitly set CONFIG_BOOT_SWAP_USING_MOVE, an error is issued during the configuration phase of the build, complaining about the unknown BOOT_SWAP_USING_MOVE configuration option:

/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/prj.conf:82: warning: attempt to assign the value 'y' to the undefined symbol BOOT_SWAP_USING_MOVE
Parsing /Users/todi/bloomlife/zephyr-workspace/zephyr/Kconfig
Loaded configuration '/Users/todi/bloomlife/zephyr-workspace/zephyr/boards/nordic/nrf5340dk/nrf5340dk_nrf5340_cpuapp_defconfig'
Merged configuration '/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/prj.conf'
Merged configuration '/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/build/lovelace-pod-firmware/zephyr/.config.sysbuild'

error: Aborting due to Kconfig warnings

CMake Error at /Users/todi/bloomlife/zephyr-workspace/zephyr/cmake/modules/kconfig.cmake:395 (message):
  command failed with return code: 1
Call Stack (most recent call first):
  /Users/todi/bloomlife/zephyr-workspace/nrf/cmake/modules/kconfig.cmake:29 (include)
  /Users/todi/bloomlife/zephyr-workspace/zephyr/cmake/modules/zephyr_default.cmake:132 (include)
  /Users/todi/bloomlife/zephyr-workspace/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
  /Users/todi/bloomlife/zephyr-workspace/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:92 (include_boilerplate)
  CMakeLists.txt:29 (find_package)


-- Configuring incomplete, errors occurred!

This is the relevant part of the prj.config file:

CONFIG_MCUBOOT_BOOTUTIL_LIB=y
CONFIG_BOOT_SWAP_USING_MOVE=y

When I try to instead add `SB_CONFIG_BOOT_SWAP_USING_MOVE=y` to sysbuild.conf, I get the very same error.

/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/sysbuild.conf:22: warning: attempt to assign the value 'y' to the undefined symbol BOOT_SWAP_USING_MOVE
Parsing /Users/todi/bloomlife/zephyr-workspace/zephyr/share/sysbuild/Kconfig
Loaded configuration '/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/build/_sysbuild/empty.conf'
Merged configuration '/Users/todi/bloomlife/zephyr-workspace/lovelace-pod-firmware/sysbuild.conf'

error: Aborting due to Kconfig warnings

What do I have to do, to use that library?

best regards and thanks in advance,

Torsten

Nordic SDK version used: v2.7.99-cs2

[Menon]

Hello Torsten,

Sorry for getting back to you so late. I took a long vacation and resumed work this week. Usually, some of my colleagues would take over in my absence, but I guess we were very understaffed during the Christmas period, which caused this case to remain pending for a long time.

Regarding your issue:

• CONFIG_BOOT_SWAP_USING_MOVE=y: The use of Swap is not recommended as MCUBoot does not support image swapping (test swaps) for the network core due to the way RAM and PCD interact during reversion.
• CONFIG_BOOT_UPGRADE_ONLY: The simultaneous update of multiple images does not support network core image reversion, so you need to disable application image reversion.

The application core can be reverted, but doing so breaks the network core upon reversal, as the reversion process overwrites the network core with the content currently in the RAM that PCD uses. To enable this, define the CONFIG_USE_NRF53_MULTI_IMAGE_WITHOUT_UPGRADE_ONLY Kconfig option in the project-level Kconfig file. Once defined, you can activate it by setting CONFIG_USE_NRF53_MULTI_IMAGE_WITHOUT_UPGRADE_ONLY.

Refer Simultaneous multi-image DFU with nRF5340

Kind Regards,

Abhijith