Zephyr 4.4.0 (Working Draft)

We are pleased to announce the release of Zephyr version 4.4.0.

Major enhancements with this release include:

An overview of the changes required or recommended when migrating your application from Zephyr v4.3.0 to Zephyr v4.4.0 can be found in the separate migration guide.

The following sections provide detailed lists of changes by component.

Security Vulnerability Related

The following CVEs are addressed by this release:

• CVE 2025-53022 (TF-M) FWU does not check the length of the TLV’s payload

API Changes

• Architectures

  • Xtensa

    • Removed as these are architectural features:

      • CONFIG_XTENSA_MMU_DOUBLE_MAP

      • CONFIG_XTENSA_RPO_CACHE

      • CONFIG_XTENSA_CACHED_REGION

      • CONFIG_XTENSA_UNCACHED_REGION

Removed APIs and options

Deprecated APIs and options

• Bluetooth

  • Mesh

    • The function bt_mesh_input_number() was deprecated. Applications should use bt_mesh_input_numeric() instead.

    • The callback output_number in bt_mesh_prov structure was deprecated. Applications should use output_numeric callback instead.

  • Host

    • bt_conn_le_info.interval has been deprecated. Use bt_conn_le_info.interval_us instead. Note that the units have changed: interval was in units of 1.25 milliseconds, while interval_us is in microseconds.

• Sensors

  • NXP

    • Deprecated the mcux_lpcmp driver (drivers/sensor/nxp/mcux_lpcmp/mcux_lpcmp.c). It is currently scheduled to be removed in Zephyr 4.6, along with the mcux_lpcmp sample.

    • The new comparator_nxp_lpcmp driver (drivers/comparator/comparator_nxp_lpcmp.c) has been introduced to support NXP LPCMP peripheral. SoCs and boards that previously supported the mcux_lpcmp driver and its associated sample have now migrated to use the comparator_nxp_lpcmp driver along with the gpio_loopback test case (tests/drivers/comparator/gpio_loopback/src/test.c).

    • The original nxp,lpcmp has been renamed to nxp,sensor-lpcmp, applications using the old compatible must update their devicetree nodes to use the mcux_lpcmp driver. The nxp,lpcmp now is used for the comparator_nxp_lpcmp driver. (GitHub #100998).

New APIs and options

• Architectures

  • Xtensa

    • CONFIG_XTENSA_MMU_USE_DEFAULT_MAPPINGS

• Audio

  • PDM_DT_IO_CFG_GET

  • PDM_DT_HAS_LEFT_CHANNEL

  • PDM_DT_HAS_RIGHT_CHANNEL

• Bluetooth

  • Host

    • bt_gatt_cb_unregister() Added an API to unregister GATT callback handlers.

  • Mesh

    • bt_mesh_input_numeric() to provide provisioning numeric input OOB value.

    • output_numeric callback in bt_mesh_prov structure to output numeric values during provisioning.

  • Services

    • Introduced Alert Notification Service (ANS) CONFIG_BT_ANS

• Ethernet

  • Driver MAC address configuration with support for NVMEM cell.

    • net_eth_mac_load()

    • net_eth_mac_config

    • NET_ETH_MAC_DT_CONFIG_INIT and NET_ETH_MAC_DT_INST_CONFIG_INIT

  • Added ethernet_stats_type and optional get_stats_type callback in ethernet_api to allow filtering of ethernet statistics by type (common, vendor, or all). Drivers that support vendor-specific statistics can implement get_stats_type to skip expensive FW queries when only common stats are requested. The existing get_stats API remains unchanged for backward compatibility.

• Flash

  • jedec,mspi-nor now allows MSPI configuration of read, write and control commands separately via devicetree.

• Modem

  • CONFIG_MODEM_HL78XX_AT_SHELL

  • CONFIG_MODEM_HL78XX_AIRVANTAGE

• NVMEM

  • Flash device support

    • CONFIG_NVMEM_FLASH

    • CONFIG_NVMEM_FLASH_WRITE

• PWM

  • Extended API with PWM events

    • pwm_event_callback to hold a pwm event callback

    • pwm_init_event_callback() to help initialize a pwm_event_callback object

    • pwm_add_event_callback() to add a callback

    • pwm_remove_event_callback() to remove a callback

    • manage_event_callback in pwm_driver_api to manage pwm events

    • CONFIG_PWM_EVENT

• Power

  • The new voltage-scale property of st,stm32u5-pwr can be used to select the voltage scale manually on STM32U5 series via Devicetree. This notably enables usage of the USB controller at lower system clock frequencies.

• Settings

  • CONFIG_SETTINGS_SAVE_SINGLE_SUBTREE_WITHOUT_MODIFICATION

  • CONFIG_SETTINGS_SAVE_SINGLE_SUBTREE_WITHOUT_MODIFICATION_VALUE_SIZE

• Sys

  • COND_CASE_1

• Timeutil

  • CONFIG_TIMEUTIL_APPLY_SKEW

• Video

  • CONFIG_VIDEO_BUFFER_POOL_HEAP_SIZE

  • CONFIG_VIDEO_BUFFER_POOL_ZEPHYR_REGION

  • CONFIG_VIDEO_BUFFER_POOL_ZEPHYR_REGION_NAME

New Boards

• Ai-Thinker Co., Ltd.

  • Ai-Thinker M61-32S development board (ai_m61_32s_kit)

  • Rename ai_m62_12f and ai_wb2_12f to ai_m62_12f_kit and ai_wb2_12f_kit

New Shields

New Drivers

• Radio

  • radio-fem-two-ctrl-pins (renamed from generic-fem-two-ctrl-pins)

  • radio-gpio-coex (renamed from gpio-radio-coex)

New Samples

• Peripheral ANS

DeviceTree

• DT_CHILD_BY_UNIT_ADDR_INT

• DT_INST_CHILD_BY_UNIT_ADDR_INT

Libraries / Subsystems

• LoRa/LoRaWAN

  • lora_airtime()

Other notable changes

• TF-M was updated to version 2.2.2 (from 2.2.0). The release notes can be found at:

  • https://trustedfirmware-m.readthedocs.io/en/tf-mv2.2.2/releases/2.2.1.html

  • https://trustedfirmware-m.readthedocs.io/en/tf-mv2.2.2/releases/2.2.2.html