1.. _kconfig:
2
3Configuration System (Kconfig)
4*******************************
5
6The Zephyr kernel and subsystems can be configured at build time to adapt them
7for specific application and platform needs. Configuration is handled through
8Kconfig, which is the same configuration system used by the Linux kernel. The
9goal is to support configuration without having to change any source code.
10
11Configuration options (often called *symbols*) are defined in :file:`Kconfig`
12files, which also specify dependencies between symbols that determine what
13configurations are valid. Symbols can be grouped into menus and sub-menus to
14keep the interactive configuration interfaces organized.
15
16The output from Kconfig is a header file :file:`autoconf.h` with macros that
17can be tested at build time. Code for unused features can be compiled out to
18save space.
19
20The following sections explain how to set Kconfig configuration options, go
21into detail on how Kconfig is used within the Zephyr project, and have some
22tips and best practices for writing :file:`Kconfig` files.
23
24.. toctree::
25   :maxdepth: 1
26
27   menuconfig.rst
28   setting.rst
29   tips.rst
30   preprocessor-functions.rst
31   extensions.rst
32
33Users interested in optimizing their configuration for security should refer
34to the Zephyr Security Guide's section on the :ref:`hardening`.
35