SDK upgrade guide
Simplicity SDK 2024.12 to Simplicity SDK 2025.6: what needs attention
Migratorisk's knowledge base lists 36 documented changes between Simplicity SDK 2024.12 and Simplicity SDK 2025.6. 22 of them are rated likely to break code, configuration or builds that use them. Below is each change, what a scan also reviews on this path, and how to see which ones apply to your project.
Find which of these affect your firmware
Migratorisk scans your project on your own computer and reports only the changes your code, configuration and build actually touch. Your source code is not uploaded.
python -m pip install migratorisk migratorisk scan --project ./your-firmware --from simplicity-sdk-2024.12.0 --to simplicity-sdk-2025.6.0 --out report.html
Requires Python 3.12 or newer. Results are free and complete without sign-up; sharing a report with us is optional.
Set up the local scanOr answer a few questions insteadWhere the changes are
What changes between Simplicity SDK 2024.12 and Simplicity SDK 2025.6
Ordered by impact. Each item names the release that introduced it and links to the official source. A change only matters if your project uses what changed; the scan checks that.
Bluetooth LE: functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: cs_initiator_display_print_float_value, cs_initiator_display_set_bit_error_rate, cs_initiator_display_set_distance, cs_initiator_display_set_distance_progress, cs_initiator_display_set_likeliness, cs_initiator_display_set_rssi_distance… Code using them fails to compile or link. Covers 28 names.
Bluetooth LE: constants removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these constants from Simplicity SDK 2024.12.0: BG_VERSION_BUILD, BG_VERSION_HASH, BG_VERSION_MAJOR, BG_VERSION_MINOR, BG_VERSION_PATCH, CS_EVENT_BUF_DATA_MAX_LEN… Code using them fails to compile or link. Covers 25 names.
Peripheral drivers: functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: CORE_DECLARE_NVIC_MASK, CORE_DECLARE_NVIC_ZEROMASK, CORE_ENTER_NVIC, CORE_EXIT_NVIC, CORE_EnterNvicMask, CORE_GetNvicEnabledMask… Code using them fails to compile or link. Covers 23 names.
RAIL radio: functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: RAIL_LoadUserSeqApp, RAIL_ShutdownUserSeqApp, RAIL_USER_GetMboxMsg, RAIL_USER_InitCp, RAIL_USER_InitSemaphore, RAIL_USER_ReleaseSemaphore… Code using them fails to compile or link. Covers 14 names.
Zigbee (EmberZNet): functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: sl_zigbee_, sl_zigbee_af_incoming_packet_filter_cb, sl_zigbee_af_outgoing_packet_filter_cb, sl_zigbee_af_set_t_c_link_key_update_timer_milli_seconds, sl_zigbee_direct_calculate_admin_key, sl_zigbee_direct_calculate_basic_key… Code using them fails to compile or link. Covers 13 names.
Application utilities: constants removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these constants from Simplicity SDK 2024.12.0: APPLY_DEBUG_LOCK, GET_HOST_UPGRADE_STATUS, POST_APPLY_DEBUG_LOCK, POST_HOST_UPGRADE_STATUS, POST_VALIDATE_HOST_IMAGE, READ_VSE_VERSION… Code using them fails to compile or link. Covers 10 names.
Bluetooth Mesh: constants removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these constants from Simplicity SDK 2024.12.0: sl_btmesh_cmd_prov_test_identity_id, sl_btmesh_cmd_test_set_adv_scan_params_id, sl_btmesh_cmd_test_set_sar_config_id, sl_btmesh_cmd_test_set_segment_send_delay_id, sl_btmesh_rsp_prov_test_identity_id, sl_btmesh_rsp_test_set_adv_scan_params_id… Code using them fails to compile or link. Covers 8 names.
SDK: components removed from Simplicity SDK 2025.6.0
These SLC components are removed from Simplicity SDK 2025.6.0: zw_debug_print, zw_production, zw_zniffer_dependency, zw_zpal_production, zw_zpal_zniffer, zw_zpal_zniffer_app… A project that lists them no longer generates. Covers 8 names.
Bluetooth LE: components removed from Simplicity SDK 2025.6.0
These SLC components are removed from Simplicity SDK 2025.6.0: bluetooth_common_release, bt_fp_ncp_default, bt_fp_soc_client, bt_fp_soc_default, bt_fp_soc_server, cs_ras… A project that lists them no longer generates. Covers 7 names.
Platform services: constants removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these constants from Simplicity SDK 2024.12.0: NUM_OF_FLASH_PAGES, NVM3KEY_MFG_TOKEN_RANGE_ID, SL_POWER_MANAGER_EVENT_TRANSITION_ENTERING_EM3, SL_POWER_MANAGER_EVENT_TRANSITION_LEAVING_EM3, USERDATA_END, USER_DATA_SIZE. Code using them fails to compile or link. Covers 6 names.
Zigbee (EmberZNet): constants removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these constants from Simplicity SDK 2024.12.0: GP_ARGS, GP_PARAMS, GP_UNUSED_ARGS, SL_ZIGBEE_AF_PLUGIN_NETWORK_STEERING_STATE_VERIFY_TCLK, SL_ZIGBEE_ZIGBEE_PACKET_TYPE_INTERPAN. Code using them fails to compile or link. Covers 5 names.
Bluetooth LE: headers removed in Simplicity SDK 2025.6.0
These headers exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: cs_ras.h, cs_reflector_event_buf.h, sl_btctrl_hci_reset.h, sl_gatt_service_gas.h. Code that includes them stops compiling. Covers 4 names.
Bluetooth LE: types removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these types from Simplicity SDK 2024.12.0: cs_event_data_t, cs_result_t, cs_tx_power_t, ras_opcode_t. Code using them fails to compile or link. Covers 4 names.
Bluetooth Mesh: functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: sl_btmesh_prov_test_identity, sl_btmesh_test_set_adv_scan_params, sl_btmesh_test_set_sar_config, sl_btmesh_test_set_segment_send_delay. Code using them fails to compile or link. Covers 4 names.
Platform services: headers removed in Simplicity SDK 2025.6.0
These headers exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: sl_device_init_nvic.h, sl_memory.h, sl_memory_region.h, sl_ram_interrupt_vector_init.h. Code that includes them stops compiling. Covers 4 names.
RAIL radio: types removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these types from Simplicity SDK 2024.12.0: RAIL_SeqUserAppInfo_t, RAIL_UserCommonGlobal_t, RAIL_UserCpReq_t, UserSeqShMem_t. Code using them fails to compile or link. Covers 4 names.
Platform services: components removed from Simplicity SDK 2025.6.0
These SLC components are removed from Simplicity SDK 2025.6.0: memory_manager_pool_power_aware, sl_system_process_action, token_manager_test. A project that lists them no longer generates. Covers 3 names.
Application utilities: headers removed in Simplicity SDK 2025.6.0
These headers exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: app_host_firmware_image.h, app_se_manager_host_firmware_upgrade.h. Code that includes them stops compiling. Covers 2 names.
Component cs_initiator changed in Simplicity SDK 2025.6.0
In sisdk-2025.6.0 the cs_initiator component was significantly changed along with its public API. The automated upgrade is not possible, it has to be carried out manually. The recommended way to upgrade your project using this component is to create a new project from sisdk-2025.6.0 and migrate your changes (e.g. application logic) on top of that.
Peripheral drivers: types removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these types from Simplicity SDK 2024.12.0: CORE_nvicMask_t. Code using them fails to compile or link.
Platform services: types removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these types from Simplicity SDK 2024.12.0: sl_iostream_dma_context_t. Code using them fails to compile or link.
RAIL radio: components removed from Simplicity SDK 2025.6.0
These SLC components are removed from Simplicity SDK 2025.6.0: rail_util_eff. A project that lists them no longer generates.
Bluetooth LE: configuration options removed in Simplicity SDK 2025.6.0
These component configuration options exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: CS_INITIATOR_CS_EVENT_BUF_SIZE, CS_INITIATOR_MAX_STEP_DATA_LEN, CS_INITIATOR_MAX_SUBEVENT_PER_PROC, SL_BT_DEFAULT_MAX_POWER_LEVEL, SL_BT_DEFAULT_MIN_POWER_LEVEL, SL_GATT_SERVICE_GAS_ECO2_INVALID… Values set for them in the project's config headers or .slcp are ignored, so the behaviour they controlled is silently lost. Covers 7 names.
Bluetooth LE: functions deprecated in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 marks these functions as deprecated: sl_bgapi_get_command_response, sl_bgapi_handle_command, sl_bgapi_unlock, sl_bt_get_command_response, sl_bt_handle_command. They still build with a warning and are removed in a later release. Covers 5 names.
sl_system is deprecated in favour of sl_main
In Simplicity SDK 2025.6.0 the sl_system component was deprecated and support for bare-metal applications through it removed; bare-metal projects move to sl_system_compatibility on upgrade. RTOS applications must move to sl_main (or define SL_SUPPRESS_DEPRECATION_WARNINGS_SDK_2025_6 for now); sl_system support for RTOS applications is removed in 2026.6.0. Covers 4 names.
Platform services: components deprecated in Simplicity SDK 2025.6.0
These SLC components are deprecated in Simplicity SDK 2025.6.0: sl_memory, sl_system_init, sl_system_kernel. They still work but are removed in a later release. Covers 3 names.
Bluetooth LE: components deprecated in Simplicity SDK 2025.6.0
These SLC components are deprecated in Simplicity SDK 2025.6.0: bt_fp_aoa, gatt_service_device_information. They still work but are removed in a later release. Covers 2 names.
Platform services: configuration options removed in Simplicity SDK 2025.6.0
These component configuration options exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: SL_INTERRUPT_MANAGER_S2_INTERRUPTS_IN_RAM, SL_POWER_MANAGER_QSPI_CLOCK_SWITCH_IN_SLEEP_EN. Values set for them in the project's config headers or .slcp are ignored, so the behaviour they controlled is silently lost. Covers 2 names.
RAIL radio: configuration options removed in Simplicity SDK 2025.6.0
These component configuration options exist in Simplicity SDK 2024.12.0 and are gone in Simplicity SDK 2025.6.0: SL_RAIL_UTIL_IEEE802154_2P4_1MBPS_FEC_PHY_ENABLED, SL_RAIL_UTIL_IEEE802154_2P4_2MBPS_PHY_ENABLED. Values set for them in the project's config headers or .slcp are ignored, so the behaviour they controlled is silently lost. Covers 2 names.
Component bluetooth_feature_external_bonding_database changed in Simplicity SDK 2025.6.0
Component bluetooth_feature_external_bonding_database requires psa_its component. Upgrade adds the required component.
Component btmesh_stack changed in Simplicity SDK 2025.6.0
The Bluetooth Mesh stack model configuration data storage format is changed in SDK release 9.0.0. The storage format defaults to the new btmesh_stack_model_storage_v2 format in new projects. Upgrade adds the btmesh_stack_model_storage_v1 component to the project to preserve the old format in existing projects which are based on previous SiSDK version. The new btmesh_stack_model_storage_v2 storage format is superior to the old format because it implements the storage in a manner that supports more complex firmware updates, but is not backwards-compatible. The project can be migrated to the new format by replacing the btmesh_stack_model_storage_v1 component with the btmesh_stack_model_storage_v2 and btmesh_stack_model_storage_v1_to_v2_migrate components. The persistent storage migration shall be executed by calling the sl_btmesh_model_migration_migrate_models API from sl_btmesh_api.h file before the node/provisioner initialization. See details in the API documentation. If the migration is done then the btmesh_stack_model_storage_v1_to_v2_migrate component can be removed from the project in newer application versions.
Component cpc_secondary_recommended_interface replaced by cpc_secondary_recommended_uart_interface in Simplicity SDK 2025.6.0
In sisdk-2025.6.0 the cpc_secondary_recommended_interface component was renamed cpc_secondary_recommended_uart_interface. Remove the cpc_secondary_recommended_interface component from your project.
Component ram_interrupt_vector_init replaced by interrupt_manager_vector_table_in_ram in Simplicity SDK 2025.6.0
In simplicity_sdk 2024.6.0, the ram_interrupt_vector_init component was deprecated and replaced by interrupt_manager. The ram_interrupt_vector_init component will be automatically replaced by interrupt_manager_vector_table_in_ram in your project.
Component silabs_core_sl_malloc replaced by memory_manager in Simplicity SDK 2025.6.0
In simplicity_sdk 2025.6.0 the silabs_core_sl_malloc component was removed and replaced by memory_manager. Remove the silabs_core_sl_malloc component from your project.
Security: functions removed in Simplicity SDK 2025.6.0
Simplicity SDK 2025.6.0 no longer declares these functions from Simplicity SDK 2024.12.0: sli_se_handle_mailbox_response. Code using them fails to compile or link.
Component zigbee_pro_stack_rail_mux replaced by zigbee_pro_stack in Simplicity SDK 2025.6.0
The zigbee_pro_stack_rail_mux component has been replaced with a more flexible zigbee_pro_stack component that automatically includes RAIL MUX support when available. No action is needed
What a scan of this path also reviews
Beyond the documented changes, Migratorisk reviews these upgrade risks for Silicon Labs SDK projects on this path. Each one is reported only when the project shows the trigger.
Field updates must still be accepted by the bootloader on deployed devices
When it applies: The application updates itself in the field (OTA DFU, AppLoader, Zigbee OTA or Mesh DFU) through the Gecko Bootloader already on each device.
Why it matters: New releases change stack sizes and defaults, often growing the image; the new application must still fit the bootloader's download slot and use the same signing keys.
What to do: Keep the GBL signing and encryption keys, the storage slot layout and the application start address; check the new image size against the download slot; rehearse an update from the production firmware and bootloader.
SDK extensions must move to versions built for the target SDK
When it applies: The project uses SDK extensions (for example Matter, WiSeConnect or AI/ML) on top of the Silicon Labs SDK.
Why it matters: Each extension release is built and tested against one SDK release. Mixing versions fails to generate or builds an untested combination.
What to do: Pick the extension release that names the target SDK in its release notes and upgrade it together with the SDK.
A copy of the SDK lives inside the project
When it applies: The project contains a copied Gecko or Simplicity SDK folder instead of linking to an installed SDK.
Why it matters: An upgrade does not touch the copy. Local patches to it are easily lost or silently kept, and the build may mix old and new SDK files.
What to do: List local changes to the copied SDK (diff it against the matching release), then replace the copy with the target SDK and re-apply only the changes still needed.
Zigbee host and NCP must be upgraded together
When it applies: The project is a Zigbee host application that talks to an NCP over EZSP.
Why it matters: EZSP versions change between SDK releases; a host only talks to an NCP built with a compatible stack.
What to do: Upgrade host and NCP firmware as one release, and make sure the host can still reflash an NCP that runs the old firmware.
Updating the Gecko Bootloader itself
When it applies: The repository builds a Gecko Bootloader with the SDK.
Why it matters: A new bootloader must keep the storage layout, keys and application interface of the one on deployed devices, and it can only be replaced in the field if the bootloader upgrade path was planned.
What to do: Decide whether deployed devices keep their current bootloader (usual) or receive a bootloader upgrade; if so, test the upgrade image on production devices before release.
The project must be upgraded and regenerated with SLC
When it applies: Silicon Labs projects are generated from the .slcp by SLC (Simplicity Studio or slc-cli).
Why it matters: New releases rename, split and remove components and configuration options (Silicon Labs' upgrade rules apply most of these automatically), and regenerate autogen/ and config headers.
What to do: Run the project upgrade (Simplicity Studio's Upgrade, or slc upgrade) on a clean branch, regenerate, then review the diff of config/ and the .slcp before touching application code. Never keep hand edits in autogen/.
Stored data must survive the update
When it applies: The firmware keeps data in NVM3 or tokens (network keys, bonding data, Mesh provisioning, application settings).
Why it matters: Stack releases occasionally change stored data formats (for example the Bluetooth Mesh model storage format in 2025.6); data written by the old firmware must still be read correctly.
What to do: Update a device that has real stored data (joined network, bonded phone, provisioned node) from the production firmware and check it keeps working without re-pairing or re-commissioning.
Check the Secure Engine firmware required by the target SDK
When it applies: The project targets a Series 2 device, whose Secure Engine runs its own firmware.
Why it matters: Newer SDKs are released with a matching Secure Engine firmware version; security features and some PSA Crypto behaviour depend on it, and devices in the field keep the SE firmware they shipped with unless it is updated.
What to do: Compare the SE firmware version on production devices with the one in the target SDK's platform release notes, and decide whether the update must include an SE firmware upgrade.
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Related upgrade paths
- Gecko SDK 4.4 to Simplicity SDK 2025.6
- Simplicity SDK 2024.6 to Simplicity SDK 2024.12
- Simplicity SDK 2025.6 to Simplicity SDK 2025.12
- Simplicity SDK 2025.6 to Simplicity SDK 2026.6
Generated from the rule catalog of Migratorisk 0.3.0. This is an automated summary of published SDK changes, not a review of your project, and it does not replace builds and device tests. How the scanner is validated.