Settings subsystem fails initialization on the nrf5340DK

Question

I found an issue with a settings subsystem implementation on an nrf5340DK board I'm working with. I originally implemented the settings subsystem on an nrf52840DK which worked fine there. Later I needed to port that functionality over to the nrf5340DK where things fell apart. I debugged the issue down to a flash read command called from nvs_flash_rd() (ncs\v2.3.0\zephyr\subsys\fs
vs
vs.c). The failure is an access violation which triggers a reboot. I ran the settings subsystem sample on the nrf5340Dk and that worked fine. So I started working to pin down config settings that may be exposing this issue. I found that CONFIG_BOOTLOADER_MCUBOOT=y along with CONFIG_FILE_SYSTEM=y and CONFIG_FILE_SYSTEM_LITTLEFS=y will cause the settings subsystem initialization to fail. Setting CONFIG_BOOTLOADER_MCUBOOT or the file system settings by themselves will work but, setting them together causes an access violation. Will you please take a look at the v2.3.0 settings subsystem sample along with my modified prj.config file and see if you can figure out what the problem is? 
 
 6366.prj.conf

AHaug · Accepted Answer

You are absolutely correct, the config is already present in the configuration you provided. Wow, that's interesting. It is however not present in a pristine version of the settings subsystem sample for NCS v2.3.0 
 What I did was to take a pristine settings subsystem sample, which has the configuration like this 
 CONFIG_STDOUT_CONSOLE=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y

CONFIG_SETTINGS=y
CONFIG_SETTINGS_RUNTIME=y
 
 Then I added 
 ############### Added Configs ################

CONFIG_BOOTLOADER_MCUBOOT=y
CONFIG_FILE_SYSTEM=y
CONFIG_FILE_SYSTEM_LITTLEFS=y
 
 which resulted in the following result for the 52840DK (nrf52840dk_nrf52840) and the 5340DK (nrf5340dk_nrf5340_cpuapp) 
 
 After that I added CONFIG_NVS=y to the bottom of the prj.conf 
 which added the settings_storage partition to the partitioning as well as successfully initialized the settings subsys (from the device terminal output) 
 
 So I find it interesting that this does not work on your end 
 
 Have you made any other modifications to the project? 
 Which build target did you build for? 
 What revision is the 5340DK you have available? 
 Could you check the partition map for the modified to see if settings_storage is located there? 
 
 Here's the zip of the project I built and ran. Firmware for 5340 with modifications is in build_2 (can be flashed through west flash -d build_2 ) 
 2063.settings_with_NVS.zip 
 Kind regards, Andreas

kseegmiller · Answer

Another developer on the project was having similar flash issues and found he could create a pm_static.yml partition file. He also added the settings subsystem mapping as well. This appears to have resolved the issue although admittedly I still don't why the auto gen'd partition.yml didn't work. 
 
 Best regards, 
 Kyle