Warning FLASH_SIMULATOR unassigned starting from NCS SDK 2.7.0 due to missing default flash_sim.overlay from build

[Alfredo Antolinez]

I have found that in NCS SDK 2.6.2 it was very simple to enable FLASH_SIMULATOR as part of the mcuboot configuration overlays. But starting from SDK 2.7.0, I keep getting the following warnings:

warning: FLASH_SIMULATOR (defined at drivers/flash/Kconfig.simulator:6) was assigned the value 'y'
but got the value 'n'. Check these unsatisfied dependencies: DT_HAS_ZEPHYR_SIM_FLASH_ENABLED (=n).
See http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_FLASH_SIMULATOR and/or look up
FLASH_SIMULATOR in the menuconfig/guiconfig interface. The Application Development Primer, Setting
Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be helpful
too.


warning: FLASH_SIMULATOR_DOUBLE_WRITES (defined at drivers/flash/Kconfig.simulator:42) was assigned
the value 'y' but got the value 'n'. Check these unsatisfied dependencies: FLASH_SIMULATOR (=n). See
http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_FLASH_SIMULATOR_DOUBLE_WRITES and/or look
up FLASH_SIMULATOR_DOUBLE_WRITES in the menuconfig/guiconfig interface. The Application Development
Primer, Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual
might be helpful too.

By examining some of my application's build artifacts built under SDK 2.6.2, I see that the flash_sim.overlay was being added by default to the build in the following in build/CMakeCache.txt:

//Default mcuboot configuration file
mcuboot_DTC_OVERLAY_FILE:STRING=/opt/nordic/ncs/v2.6.2/nrf/modules/mcuboot/flash_sim.overlay;/opt/nordic/ncs/v2.6.2/nrf/modules/mcuboot/usb.overlay;/Users/alfredoantolinez/dev/sensor_wearable/wearable/child_image/mcuboot/boards/nrf5340dk_nrf5340_cpuapp.overlay

When looking at the same file under a build with 2.7.0 and up, I only see:

//devicetree overlay file defined by main application
mcuboot_DTC_OVERLAY_FILE:INTERNAL=/{MYPROJPATH}/sysbuild/mcuboot.overlay

I imagine this is a product of switching to sysbuild and possibly providing flexibility to the user to use or not whatever they want for their builds. But I do liked the option to use the overlay provided by Nordic for this functionality.

What is the proper way to enable FLASH_SIMULATOR and including the flash_sim.overlay from Nordic starting from 2.7.0 as it is not clear to me?

I tried to add the following line in the project's CMakeLists.txt file right under the 

cmake_minimum_required

:

set(mcuboot_DTC_OVERLAY_FILE ${ZEPHYR_BASE}/../nrf/modules/mcuboot/flash_sim.overlay)

But that does not seem to be doing anything to the build.

Any help would be appreciated.

Thank you,

Alfredo

[Alfredo Antolinez]

Update: I have figured out how to properly configure to enable FLASH_SIMULATOR and include the flash_sim.overlay in the project.

In order to do this, I had to enable the following sysbuild configuration:

SB_CONFIG_SECURE_BOOT_NETCORE=y
SB_CONFIG_NETCORE_APP_UPDATE=y

The primary goal for this configuration that I am trying to get working is for network core updates.

Now, after getting around the FLASH_SIMULATOR warning, I still get an assertion failure related to partitions during the build:

/opt/nordic/ncs/v2.9.0/zephyr/include/zephyr/toolchain/gcc.h:87:36: error: static assertion failed: "Missing partitions?"
   87 | #define BUILD_ASSERT(EXPR, MSG...) _Static_assert((EXPR), "" MSG)
      |                                    ^~~~~~~~~~~~~~
/opt/nordic/ncs/v2.9.0/zephyr/subsys/mgmt/mcumgr/grp/img_mgmt/src/zephyr_img_mgmt.c:43:1: note: in expansion of macro 'BUILD_ASSERT'
   43 | BUILD_ASSERT(FIXED_PARTITION_EXISTS(SLOT2_PARTITION) &&
      | ^~~~~~~~~~~~

My understanding of the assertion is that my dts is missing a slot3_partition.. but I was also missing it in my SDK 2.6.2 build but I did not have this issue.

See my current sysbuild.conf

# MCUboot configuration
SB_CONFIG_BOOTLOADER_MCUBOOT=y
SB_CONFIG_MCUBOOT_MODE_OVERWRITE_ONLY=y
SB_CONFIG_MCUBOOT_UPDATEABLE_IMAGES=2

# Enable net core update (specifically for flash simualtor use)
SB_CONFIG_SECURE_BOOT_NETCORE=y
SB_CONFIG_NETCORE_APP_UPDATE=y

# HCI IPC configuration
SB_CONFIG_NETCORE_HCI_IPC=y

See my mcuboot.conf

CONFIG_PM_PARTITION_SIZE_MCUBOOT=0x10000
CONFIG_BOOT_MAX_IMG_SECTORS=256

#CONFIG_BOOT_UPGRADE_ONLY=y         # Unused bc sysbuild
#CONFIG_UPDATEABLE_IMAGE_NUMBER=2   # Unused bc sysbuild
CONFIG_FLASH_SIMULATOR=y
CONFIG_FLASH_SIMULATOR_STATS=n
CONFIG_FLASH_SIMULATOR_DOUBLE_WRITES=y

Any help to get around the slot3_partition assertion is greatly appreciated.

Thank you,

Alfredo

[Alfredo Antolinez]

It appears the only sysbuild configuration I was missing (based on nrf/samples/bluetooth/fast_pair/locator_tag sample) was 

SB_CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

After adding that to sysbuild.conf, the assertion disappeared.

I still don't fully understand this series of configuration options, so if anyone has a clearer understanding, I'd appreciate the explanation.

 

Thank you,

Alfredo