Migration guide to Zephyr v4.1.0 (Working Draft)

This document describes the changes required when migrating your application from Zephyr v4.0.0 to Zephyr v4.1.0.

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

Build System

Kernel

Boards

Modules

Mbed TLS

• If a platform has a CSPRNG source available (i.e. CONFIG_CSPRNG_ENABLED is set), then the Kconfig option CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG is the default choice for random number source instead of CONFIG_MBEDTLS_PSA_CRYPTO_LEGACY_RNG. This helps in reducing ROM/RAM footprint of the Mbed TLS library.

Trusted Firmware-M

LVGL

• The config option CONFIG_LV_Z_FLUSH_THREAD_PRIO is now called CONFIG_LV_Z_FLUSH_THREAD_PRIORITY and its value is now interpreted as an absolute priority instead of a cooperative one.

Device Drivers and Devicetree

Controller Area Network (CAN)

Display

Enhanced Serial Peripheral Interface (eSPI)

GNSS

Input

Interrupt Controller

LED Strip

Sensors

Serial

Stepper

• Renamed the compatible from zephyr,gpio-steppers to zephyr,gpio-stepper.

Regulator

Bluetooth

Bluetooth HCI

Bluetooth Mesh

Bluetooth Audio

Bluetooth Classic

Bluetooth Host

Bluetooth Crypto

Networking

Other Subsystems

Flash map

hawkBit

MCUmgr

Modem

Architectures

• native/POSIX

  • CONFIG_NATIVE_APPLICATION has been deprecated. Out-of-tree boards using this option should migrate to the native_simulator runner (GitHub #81232). For an example of how this was done with a board in-tree check GitHub #61481.

  • For the native_sim target CONFIG_NATIVE_SIM_NATIVE_POSIX_COMPAT has been switched to n by default, and this option has been deprecated. Ensure your code does not use the CONFIG_BOARD_NATIVE_POSIX option anymore (GitHub #81232).