Migration guide to Zephyr v4.6.0 (Working Draft)

This document describes the changes required when migrating your application from Zephyr v4.5.0 to Zephyr v4.6.0.

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

ADC

• nxp,lpc-lpadc channels that use ADC_GAIN_1_2 for the 30/64 partial scale should use ADC_GAIN_15_32: with ADC_GAIN_1_2, which still selects that scale, the conversions of adc_raw_to_millivolts_dt() and adc_raw_to_millivolts() are 6.25% too low.

Ethernet

• CONFIG_ETH_PHY_DRIVER is no longer enabled by default. It is now selected by the Ethernet drivers that need a PHY driver. Out-of-tree Ethernet drivers that use a PHY driver must select it as well. (GitHub #120871)

OPAMP

• The NXP OPAMP drivers (nxp,opamp and nxp,opamp-fast) hold a power state constraint while the device is active, and the OPAMP nodes declare zephyr,disabling-power-states. With CONFIG_PM_POLICY_DEVICE_CONSTRAINTS an enabled OPAMP therefore keeps the system out of Power Down and Deep Power Down for as long as it is active, which without CONFIG_PM_DEVICE_RUNTIME is from init onwards. Enable device runtime PM for the node, or suspend it explicitly, to let the system reach those states. (GitHub #122135)

• nxp,opamp-fast no longer enables an instance marked with is-reference-source from its init function; the instance follows its own power state like every other instance. With CONFIG_PM_DEVICE_RUNTIME an application has to hold a runtime reference on the reference source while it measures an amplifier fed by it. Builds without device runtime PM are unaffected: the device is resumed at init and the instance comes up enabled as before. (GitHub #122135)

Bluetooth

Bluetooth Classic

• The L2CAP BR/EDR ECHO API is now only available with CONFIG_BT_TESTING: bt_l2cap_br_echo_cb, bt_l2cap_br_echo_cb_register(), bt_l2cap_br_echo_cb_unregister(), bt_l2cap_br_echo_req() and bt_l2cap_br_echo_rsp(). The stack answers a received ECHO request with an ECHO response without data, unless a registered req callback handles it.

Networking

Other subsystems

Modules

Architectures