Custom CMake Toolchains¶
To use a custom toolchain defined in an external CMake file, set these environment variables:
Set
ZEPHYR_TOOLCHAIN_VARIANT
to your toolchain’s nameSet
TOOLCHAIN_ROOT
to the path to the directory containing your toolchain’s CMake configuration files.
Zephyr will then include the toolchain cmake files located in the
TOOLCHAIN_ROOT
directory:
cmake/toolchain/generic.cmake
: configures the toolchain for “generic” use, which mostly means running the C preprocessor on devicetree input files.cmake/toolchain/target.cmake
: configures the toolchain for “target” use, i.e. building Zephyr and your application’s source code.
See the zephyr files cmake/generic_toolchain.cmake and
cmake/target_toolchain.cmake for more details on what your
generic.cmake
and target.cmake
files should contain.
You can also set ZEPHYR_TOOLCHAIN_VARIANT
and TOOLCHAIN_ROOT
as CMake
variables when generating a build system for a Zephyr application, like so:
west build ... -- -DZEPHYR_TOOLCHAIN_VARIANT=... -DTOOLCHAIN_ROOT=...
cmake -DZEPHYR_TOOLCHAIN_VARIANT=... -DTOOLCHAIN_ROOT=...
If you do this, -C <initial-cache>
cmake option may useful. If you save
your ZEPHYR_TOOLCHAIN_VARIANT, TOOLCHAIN_ROOT, and other
settings in a file named my-toolchain.cmake
, you can then invoke cmake
as cmake -C my-toolchain.cmake ...
to save typing.