MCUBOOT Bootloader info

Question

Hi,

TLDR: Tried the new BLINFO feature on an existing app, upgrading to 2.6.1 SDK (Zephyr 3.5.99). App does not boot after merged.hex flashed.

So we are updating our project to NRF SDK 2.6.1. I saw that this version of the sdk use a version of Zephyr around 3.5.0. So I saw this new feature that they added in Zephyr 3.5.0 for blinfo (bootloader info). I followed this tutorial https://docs.zephyrproject.org/latest/services/retention/blinfo.html

So I followed all the steps, I added the following data in the device trees of mcuboot and for my app as mentionned in the tutorial. We use NRF9160DK for your information.

/ {
	sram0@2003F000 {
			compatible = "zephyr,memory-region", "mmio-sram";
			reg = <0x2003F000 DT_SIZE_K(1)>;
			zephyr,memory-region = "RetainedMem";
			status = "okay";

			retainedmem {
					compatible = "zephyr,retained-ram";
					status = "okay";
					#address-cells = <1>;
					#size-cells = <1>;

					boot_info0: boot_info@0 {
							compatible = "zephyr,retention";
							status = "okay";
							reg = <0x0 0x100>;
					};
			};
	};

	chosen {
			zephyr,bootloader-info = &boot_info0;
	};
};

&sram0 {
	reg = <0x20000000 DT_SIZE_K(255)>;
};

Then in my mcuboot child image config I add the following :

CONFIG_RETAINED_MEM=y
CONFIG_RETENTION=y
CONFIG_BOOT_SHARE_DATA=y
CONFIG_BOOT_SHARE_DATA_BOOTINFO=y
CONFIG_BOOT_SHARE_BACKEND_RETENTION=y
CONFIG_RETENTION_BOOTLOADER_INFO_OUTPUT_FUNCTION=y

Then in my app prj.conf I add the following

CONFIG_RETAINED_MEM=y
CONFIG_RETENTION=y
CONFIG_RETENTION_BOOTLOADER_INFO=y
CONFIG_RETENTION_BOOTLOADER_INFO_TYPE_MCUBOOT=y

The tutorial seems pretty straight forward. I dont add the Kconfig for settings as I only need to access the info from the ```blinfo_lookup``` function. So then I am able to build the project and flash it with SDK 2.6.1 (to make sure its not just the extension not on the right SDK, I check which version of zephyr is used when building and it is indeed using the appropriate version). So then after I flash, the app does not boot ? It seems that the bootloader is not able to start the application. We have serial recovery enabled and I am still able to access that mode though, but not the app.

I saw that the tutorial mention it is used for NRF52DK but as I was able to go back to the SRAM device tree through vscode I saw that they add the same address range ?

I was wondering if this feature was adopted with the NRF SDK. As I saw that the specific SDK documentation didn't seem to mention anything related to it, but I was able to find that in the Zephyr documentation