Zephyr 4.3.0 (Working Draft)

We are pleased to announce the release of Zephyr version 4.3.0.

Major enhancements with this release include:

An overview of the changes required or recommended when migrating your application from Zephyr v4.2.0 to Zephyr v4.3.0 can be found in the separate migration guide.

The following sections provide detailed lists of changes by component.

API Changes

RTIO
- rtio_is_spi()
- rtio_is_cspi()
- rtio_is_i3c()
- rtio_read_regs_async()

Removed APIs and options

The TinyCrypt library was removed as the upstream version is no longer maintained. PSA Crypto API is now the recommended cryptographic library for Zephyr.

Deprecated APIs and options

New APIs and options

Architectures
- CONFIG_SRAM_SW_ISR_TABLE
- ARM (Cortex-M) system state save/restore primitives
  - z_arm_save_scb_context() / z_arm_restore_scb_context()
  - z_arm_save_mpu_context() / z_arm_restore_mpu_context()
  - Existing z_arm_save_fp_context() and z_arm_save_fp_context() have also been updated
Bluetooth
- Audio
  - bt_audio_codec_cfg now contains a target_latency and a target_phy option
  - bt_bap_broadcast_source_foreach_stream()
  - bt_bap_stream now contains an iso field as a reference to the ISO channel
- Host
  - bt_iso_unicast_info now contains a cig_id and a cis_id field
  - bt_iso_broadcaster_info now contains a big_handle and a bis_number field
  - bt_iso_sync_receiver_info now contains a big_handle and a bis_number field
Display
- PIXEL_FORMAT_AL_88
- SDL
  - CONFIG_SDL_DISPLAY_DEFAULT_PIXEL_FORMAT_AL_88
  - CONFIG_SDL_DISPLAY_COLOR_TINT
Logging:
- Added rate-limited logging macros to prevent log flooding when messages are generated frequently.
  - LOG_ERR_RATELIMIT - Rate-limited error logging macro (convenience)
  - LOG_WRN_RATELIMIT - Rate-limited warning logging macro (convenience)
  - LOG_INF_RATELIMIT - Rate-limited info logging macro (convenience)
  - LOG_DBG_RATELIMIT - Rate-limited debug logging macro (convenience)
  - LOG_HEXDUMP_ERR_RATELIMIT - Rate-limited error hexdump macro (convenience)
  - LOG_HEXDUMP_WRN_RATELIMIT - Rate-limited warning hexdump macro (convenience)
  - LOG_HEXDUMP_INF_RATELIMIT - Rate-limited info hexdump macro (convenience)
  - LOG_HEXDUMP_DBG_RATELIMIT - Rate-limited debug hexdump macro (convenience)
  - LOG_ERR_RATELIMIT_RATE - Rate-limited error logging macro (explicit rate)
  - LOG_WRN_RATELIMIT_RATE - Rate-limited warning logging macro (explicit rate)
  - LOG_INF_RATELIMIT_RATE - Rate-limited info logging macro (explicit rate)
  - LOG_DBG_RATELIMIT_RATE - Rate-limited debug logging macro (explicit rate)
  - LOG_HEXDUMP_ERR_RATELIMIT_RATE - Rate-limited error hexdump macro (explicit rate)
  - LOG_HEXDUMP_WRN_RATELIMIT_RATE - Rate-limited warning hexdump macro (explicit rate)
  - LOG_HEXDUMP_INF_RATELIMIT_RATE - Rate-limited info hexdump macro (explicit rate)
  - LOG_HEXDUMP_DBG_RATELIMIT_RATE - Rate-limited debug hexdump macro (explicit rate)
Power management
- pm_device_driver_deinit()
Settings
- CONFIG_SETTINGS_TFM_ITS

New Boards

New Drivers

Input
- chipsemi,chsc5x
Interrupt controller
- STM32 EXTI interrupt/event controller (st,stm32-exti) has a dedicated driver and API now, separate from STM32 GPIO Interrupt Control driver.
RTC
- STM32 RTC driver has been updated to use the new STM32 EXTI interrupt controller API

New Samples

Libraries / Subsystems

Logging:
- Added hybrid rate-limited logging macros to prevent log flooding when messages are generated frequently. The system provides both convenience macros (using default rate from CONFIG_LOG_RATELIMIT_INTERVAL_MS) and explicit rate macros (with custom rate parameter). This follows Linux’s printk_ratelimited pattern while providing more flexibility. The rate limiting is per-macro-call-site, meaning that each unique call to a rate-limited macro has its own independent rate limit. Rate-limited logging can be globally enabled/disabled via CONFIG_LOG_RATELIMIT. When rate limiting is disabled, the behavior can be controlled via CONFIG_LOG_RATELIMIT_FALLBACK to either log all messages or drop them completely. For more details, see Rate-limited logging.

Other notable changes

Nordic Semiconductor nRF54L09 PDK (nrf54l09pdk), which only targeted an emulator, has been removed from the tree. It will be replaced with a proper board definition as soon as it’s available.
Removed support for Nordic Semiconductor nRF54L20 PDK (nrf54l20pdk) since it is replaced with nRF54LM20 DK (nrf54lm20dk).