Zephyr v2.4.0 released

Maureen Helm

Hi everyone,

We are pleased to announce the release of Zephyr RTOS version 2.4.0!


Major enhancements with this release include:

  • Introduced initial support for virtual memory management.
  • Added Bluetooth host support for periodic advertisement and isochronous channels.
  • Enabled the new TCP stack, TCP2, by default. This stack was introduced in Zephyr v2.1.0 to improve network protocol testability with open source tools.
  • Introduced a new toolchain abstraction with initial implementations for GCC and LLVM/Clang, and groundwork for future support of commercial toolchains.
  • Moved to using C99 integer types and deprecate Zephyr integer types. The Zephyr types can be enabled by Kconfig DEPRECATED_ZEPHYR_INT_TYPES option.


During this release cycle we also:

  • Migrated to a new CI infrastructure.
  • Started aggregating board farm test results from multiple companies.
  • Agreed on a set of MISRA-based coding guidelines and a plan to implement them.
  • Reduced a large backlog of low priority bugs.


The detailed release notes can be found here:



The next release, v2.5.0, is scheduled for January 29th, 2021. We’ll select a release manager in the next few days. The merge window is now open!


Thank you to everyone that contributed features, documentation, testing, infrastructure, and bug fixes!



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