RE: migrate custom board from 2.9.0 to 3.4.0

John Galvin — Mon, 17 Aug 2026 09:33:54 GMT

Thanks. I am using sysbuild. I needed to because I have two builds;

One for debug where sysbuild.cong is empty

The other for release with Extra Make Arg "-DFILE_SUFFIX=release"

And my sysbuild_release.conf has the following lines:

# Step 2.1 Enable MCUboot
SB_CONFIG_BOOTLOADER_MCUBOOT=y # only works here

# STEP 2.1 - Add private key for MCUboot
SB_CONFIG_BOOT_SIGNATURE_KEY_FILE="\${APP_DIR}/FW7786-400_key.pem"

RE: migrate custom board from 2.9.0 to 3.4.0

Simon D-M — Mon, 17 Aug 2026 09:25:21 GMT

Hi,

Every time we release a new major and minor NCS version, we add a migration guide (link).

So to do the full upgrade, I would advise you to update 1 minor version at a time and follow the migration guide. This is the more systematic approach and the easier one.

v2.9.0 -> v3.0.0 : guide
v3.0.0 -> v3.1.0 : guide
v3.1.0 -> v3.2.0 : guide
v3.2.0 -> v3.3.0 : guide
v3.3.0 -> v3.4.0 : guide

I believe v2.9.0 already uses sysbuild build system, but if for some reason you weren't using it, we also have a guide for migrating from multi-image builds to sysbuild (link).

And for the "Partition Manager", it got deprecated in v3.3.0 and got disabled in v3.4.0. So you will need to update your partitions. You can find a guide on migrating to devicetree partitioning (link).

Of course if, while following the guides, you are having some issue migrating some specific part of your firmware, feel free to ask again here.

Best regards,

Simon