The ``subprojects/amrex`` directory is a Git repo, so use all standard Git
commands. Either ``cd subprojects/amrex`` to run Git commands in the ``amrex``
directory, or use ``git -C subprojects/amrex`` in the MFiX-Exa repo. For
instance, to build with the ``my-amrex-branch`` branch of the AMReX repo:
The options **ENABLE\_PARTICLES=yes**, **ENABLE\_AMRDATA=yes**, and **ENABLE\_EB=yes** are required by MFiX-Exa. ``[other amrex options]`` in the snippet above refers to any other AMReX configuration option in addition to the required ones. Please refer to the `AMReX user guide <https://amrex-codes.github.io/amrex/docs_html/BuildingAMReX.html#building-with-cmake>`_ for more details on building AMReX with CMake.
If no AMReX installation is found on the system, or if one is found but does not meet MFiX-Exa requirements, MFiX-Exa CMake falls back to **SUPERBUILD** mode.
When building in **SUPERBUILD** mode, the AMReX git repo is checked out via a git submodule before AMReX CMake build system is included into MFiX-Exa CMake infrastructure. Consequently, MFiX-Exa CMake inherents AMReX's CMake targets and configuration options, that is, MFiX-Exa and AMReX are configured and built as a single entity.
Assuming no valid AMReX installation is present on the target system, and ``AMReX_ROOT`` is not set in the environment, the following code will build MFiX-Exa in **SUPERBUILD** mode:
> git submodule update
> git status
...
nothing to commit, working tree clean
You can edit, commit, pull, and push AMReX changes from ``subprojects/amrex``.
AMReX development is outside the scope of this document. Run ``git status`` in
the top-level MFix-Exa repo to see whether the AMReX submodule has new commits,
modified files, or untracked files.
To update the AMReX submodule reference by MFiX-Exa:
Then MFiX-Exa should set ``AMREX_ROOT`` to that directory when running
``cmake``:
.. highlight:: console
``[amrex options]`` is a list of any of the AMReX configuration options listed in the `AMReX user guide <https://amrex-codes.github.io/amrex/docs_html/BuildingAMReX.html#building-with-cmake>`_
::
-DAMREX_ROOT=/absolute/path/to/amrex/installdir
Proceed to :ref:`Configuring`.
.. _Configuring:
Configuring and Generating Makefiles
------------------------------------
Run ``cmake`` to generate Makefiles for building MFiX-Exa:
.. highlight:: console
::
> cmake -S . -B builddir
Proceed to :ref:`Building`.
.. note::
By default MFiX-Exa is built with MPI support. Use ``-DENABLE_MPI=NO`` to
build without MPI.
Few more notes on building MFiX-Exa
-----------------------------------
Specifying Options
~~~~~~~~~~~~~~~~~~
The system defaults compilers can be overwritten as follows:
.. highlight:: console
::
> cmake -S . -B builddir \
[amrex options] \
[mfix options]
In the above snippet, ``[amrex options]`` is a list of any of the AMReX
configuration options listed in the `AMReX User Guide.
