Skip to main content

CHESTER SDK v4.0.0 migration guide

CHESTER SDK v4.0.0 bumps the underlying nRF Connect SDK from v2.9 to v3.4 (Zephyr 4.x, Zephyr SDK 1.0.1). This is a breaking release: the Python toolchain, the Zephyr SDK, and — for out-of-tree applications — the build system (sysbuild + DTS partitioning) all change.

Start from a v3.5.5 workspace (the last NCS v2.9 release). Confirm it builds, then apply this guide. Don't jump an older workspace straight to v4.0.0.

0. Update the workspace​

First update your west.yml to track CHESTER SDK v4.0.0:

  - name: chester
    remote: hardwario
    repo-path: chester-sdk
    revision: v4.0.0 # <-- Change here
    import: true

Then update the workspace and install the required toolchains:

# Pull updated CHESTER SDK + all modules
west update

# Update/install required python packages
west packages pip --install -- -U

# Export the Zephyr CMake package
west zephyr-export

# Install the required version of Zephyr SDK
west sdk install -t arm-zephyr-eabi

Delete any existing build directory and rebuild from scratch — sysbuild changes the build layout, so an incremental build on top of an NCS v2.9 tree will not work.

If you only build the applications shipped with the SDK, you are done here. The catalog applications were already migrated as part of v4.0.0. The rest of this guide applies to maintainers of out-of-tree applications.

1. Migrate to sysbuild + DTS partitions​

NCS v3.4 builds with sysbuild, and the CHESTER board now defines its flash layout in the device tree instead of Nordic's Partition Manager (PM). PM is disabled for the board, so pm_static.yml and child_image/ are no longer read.

Every out-of-tree app must be converted. All catalog apps were migrated in one commit, which can be used as a reference: ef27da1e applications: Migrate to sysbuild + DTS partitions.

The per-app delta:

ActionPathContent
Addsysbuild.confSB_CONFIG_BOOTLOADER_MCUBOOT=y / SB_CONFIG_MCUBOOT_MODE_SWAP_SCRATCH=y / SB_CONFIG_MERGED_HEX_FILES=y
Movechild_image/mcuboot.conf → sysbuild/mcuboot.confadd CONFIG_BOOT_MAX_IMG_SECTORS_AUTO=n (new, required)
Deletechild_image/ (whole dir)incl. child_image/mcuboot/boards/chester_nrf52840.overlay
Deletepm_static.ymlno longer read
Edit app.overlayremove PM external-flash plumbingdrop the nordic,pm-ext-flash chosen node and the manual littlefs_storage partition on &spi_flash0 — now from board DTS
Edit prj.confremove PM KconfigCONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK / CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL

The board's default DTS layout (boards/hardwario/chester/chester_nrf52840.dts) matches the old PM map, so a normal firmware update keeps existing devices' data.

Non-standard layouts: if your deployed devices used a different partition map, an OTA would move partitions and lose stored data. Reproduce the old map by redefining the partition nodes in app.overlay (the app overlay wins over the board DTS). See applications/control for the pattern — it pins littlefs-storage to its historical 24 KB size. Background: Nordic's Migrating to sysbuild.

2. Remaining source & Kconfig changes​

2a. Remove stale Kconfig (grep the whole app tree, not just prj.conf)​

TinyCrypt was removed in NCS 3.0; the BLE host uses PSA Crypto now.

-CONFIG_TINYCRYPT=y
-CONFIG_TINYCRYPT_SHA256=y
-CONFIG_ADC_TLA2021_INIT_PRIORITY=60

For generator-based apps, remove the subsystem-tinycrypt* features / extras: lines from project.yaml and regenerate — or delete the three lines from prj.conf by hand (not both). Apps that only use CONFIG_CTR_CLOUD / CONFIG_CTR_BLE get the PSA migration for free.

2b. Conditional — apply only if the feature is used​

If you…Change
drive the on-board PWM/RGB LED (ctr_led)board ships pwm_leds disabled — re-enable it in app.overlay and set zephyr,user { ctr_leds = <&gpio_leds>, <&pwm_leds>; } (see samples/ctr_led)
include TinyCrypt in src/*.cunused #include <tinycrypt/...> → delete; real hashing → PSA Crypto (<psa/crypto.h>, CONFIG_NRF_SECURITY=y, CONFIG_PSA_WANT_ALG_SHA_256=y)
init a UART/Modbus struct uart_config.stop_bits_client → .stop_bits
use the OPT3001 light sensorCONFIG_OPT3001=y → CONFIG_OPT300X=y
hardcode the TLA2024 compatibleti,tla2024 → hardwario,tla2024 (battery ti,tla2021 unchanged)
write raw BLE / low-level codeBT_LE_ADV_OPT_CONNECTABLE→BT_LE_ADV_OPT_CONN; drop USE_NAME/FORCE_NAME_IN_AD (add BT_DATA_NAME_COMPLETE); removed: CONFIG_BT_FIXED_PASSKEY, CONFIG_BT_CTLR, CONFIG_BT_TINYCRYPT_ECC; raise CONFIG_BT_BUF_EVT_RX_COUNT if lowered; shell_set_bypass() cb gained void *user_data; #include <nrf52840.h> → #include <soc.h>

Apps that touch these only through CHESTER subsystem APIs (ctr_cloud, ctr_radon, …) need no change — the fix is internal to the SDK.

Checklist​

  • Start from a working v3.5.5 (NCS v2.9) app
  • Update west.yml to track v4.0.0
  • west update → west zephyr-export → west sdk install -t arm-zephyr-eabi → west packages pip --install -- -U
  • rm -rf build and rebuild clean
  • (out-of-tree apps) add sysbuild.conf; move mcuboot conf + add CONFIG_BOOT_MAX_IMG_SECTORS_AUTO=n; delete child_image/ and pm_static.yml; strip PM plumbing from app.overlay/prj.conf (ref commit ef27da1e)
  • (non-standard layout) reproduce old partition map in app.overlay
  • Remove CONFIG_TINYCRYPT* / CONFIG_ADC_TLA2021_INIT_PRIORITY
  • Apply any 2b changes that touch your app
  • Verify partition map / OTA compatibility before deploying