Migration guide to Zephyr v4.5.0 (Working Draft)

This document describes the changes required when migrating your application from Zephyr v4.4.0 to Zephyr v4.5.0.

Any other changes (not directly related to migrating applications) can be found in the release notes.

Common 

Build System 

Kernel 

Boards 

Device Drivers and Devicetree 

Clock Control 

The nxp,imxrt11xx-arm-pll binding now uses loop-div and post-div for ARM PLL configuration. The legacy clock-mult and clock-div properties remain supported but are deprecated. Existing RT11xx overlays should be updated using the mapping loop-div = clock-mult * 2 and post-div = clock-div.

Digital Microphone 

The DMIC driver backend API now uses dmic_driver_api instead of struct _dmic_ops.

Out-of-tree DMIC drivers must rename their backend API struct definitions and switch their API instances to DEVICE_API(dmic, ...). See GitHub #107695 for examples of how in-tree drivers have been updated. Application code using dmic_configure(), dmic_trigger(), and dmic_read() is not impacted.

Flash 

jedec,spi-nand now requires a plane-bytes property, which indicates the size of each plane in the flash device. For devices with a single plane, this should be set to the same value as size-bytes.

STM32 

SoC DTSI files now consistently use interrupt priority zero for all peripherals. Applications must now explicitly configure interrupt priorities using Devicetree if they previously relied on the values found in SoC DTSI files. (GitHub #106188)

Bluetooth 

Bluetooth Audio 

bt_bap_stream.codec_cfg is now const, to better reflect that it is a read-only value. Any non-read uses of it will need to be updated with the appropriate operations such as bt_bap_stream_config(), bt_bap_stream_reconfig(), bt_bap_stream_enable() or bt_bap_stream_metadata(). (GitHub #104219)
Almost all API uses of struct bt_audio_codec_cfg * is now const, which means that once the codec_cfg has been stored in a parameter struct like bt_cap_initiator_broadcast_subgroup_param or bt_cap_unicast_audio_start_stream_param, then the parameter’s pointer cannot be used to modify the codec_cfg, and the actual definition of the struct should be modified instead. (GitHub #104219)
bt_cap_commander_broadcast_reception_start() now waits for the CAP acceptors to sync to the broadcast before completing. This means that if the broadcast source is offline, including colocated broadcast sources like the ones created by bt_cap_handover_unicast_to_broadcast(), shall be active and have the periodic advertising enabled with a configured BASE. For bt_cap_handover_unicast_to_broadcast() the newly added bt_cap_handover_cb.unicast_to_broadcast_created can be used to configure the BASE. This also means that any current checks implemented by an application to wait for receive state updates indicating successful sync can be removed, as bt_cap_commander_broadcast_reception_start() now ensures this when bt_cap_commander_cb.broadcast_reception_start is called. This also applies for bt_cap_commander_broadcast_reception_stop() in a similar manner. (GitHub #101070)
bt_bap_stream.qos is now const, to better reflect that it is a read-only value. Any non-read uses of it will need to be set with the appropriate operations such as bt_bap_unicast_group_create(), bt_bap_unicast_group_reconfig(), bt_bap_broadcast_source_create() or bt_bap_broadcast_source_reconfig(). (GitHub #104887)
Almost all API uses of struct bt_bap_qos_cfg * is now const, which means that once the qos has been stored in a parameter struct like bt_bap_broadcast_source_param or bt_bap_unicast_group_stream_param, then the parameter’s pointer cannot be used to modify the qos, and the actual definition of the struct should be modified instead. (GitHub #104219)
bt_bap_unicast_group_info.sink_pd and bt_bap_unicast_group_info.source_pd now reflect the local values defined for the group, and not the values configured for any remote ASEs. (GitHub #104887)

Bluetooth HCI 

The devicetree compatible bflb,bl70x-bt-hci has been renamed to bflb,bt-hci, now that a single binding covers all Bouffalo Lab on-chip BLE controllers (BL60x/BL70x/BL70XL). Out-of-tree boards and shields must update their devicetree nodes accordingly.

Networking 

Ethernet 

CONFIG_NET_DEFAULT_IF_ETHERNET now allows to get the first ethernet interface, instead of the first between ethernet and wifi.

Other subsystems 

Demand paging (subsys/demand_paging) is moved under Memory Management into subsys/mem_mgmt/demand_paging. Custom backing store and eviction algorithm code need to be moved there.

Modules 

Support for the CANopenNode protocol stack was moved to an external module.

hal_nxp 

S32K344: The pinmux header file for this SoC was renamed from S32K344-172MQFP-pinctrl.h to S32K344_K324_K314_172HDQFP-pinctrl.h. Out-of-tree boards must update their include directive accordingly:
```
#include <nxp/s32/S32K344_K324_K314_172HDQFP-pinctrl.h>
```