Setup and installation of Verilator
===================================


SpinalSim + Verilator is supported on both Linux and Windows platforms.

Scala
^^^^^

Don't forget to add the following in your ``build.sbt`` file:

.. code-block:: scala

   fork := true

And you will always need the following imports in your Scala testbench:

.. code-block:: scala

   import spinal.core._
   import spinal.core.sim._

Linux
^^^^^

You will also need a recent version of Verilator installed :

.. code-block:: sh

   sudo apt-get install git make autoconf g++ flex bison  # First time prerequisites
   git clone http://git.veripool.org/git/verilator   # Only first time
   unsetenv VERILATOR_ROOT  # For csh; ignore error if on bash
   unset VERILATOR_ROOT  # For bash
   cd verilator
   git pull        # Make sure we're up-to-date
   git checkout v4.040
   autoconf        # Create ./configure script
   ./configure
   make -j$(nproc)
   sudo make install
   echo "DONE"

Windows
^^^^^^^

In order to get SpinalSim + Verilator working on Windows, you have to do the following:

* Install `MSYS2 <https://www.msys2.org/>`_
* Via MSYS2 get gcc/g++/verilator (for Verilator you can compile it from the sources)
* Add ``bin`` and ``usr\bin`` of MSYS2 into your windows ``PATH`` (ie : ``C:\msys64\usr\bin;C:\msys64\mingw64\bin``)
* Check that the JAVA_HOME environnement variable point to the JDK installation folder (ie : ``C:\Program Files\Java\jdk-13.0.2``)

Then you should be able to run SpinalSim + Verilator from your Scala project without having to use MSYS2 anymore.

From a fresh install of MSYS2 MinGW 64-bit, you will have to run the following commands inside the MSYS2 MinGW 64-bits shell (enter commands one by one):

From the MinGW package manager
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: sh

   pacman -Syuu
   # Close the MSYS2 shell once you're asked to
   pacman -Syuu
   pacman -S --needed base-devel mingw-w64-x86_64-toolchain \
                      git flex\
                      mingw-w64-x86_64-cmake

   pacman -U http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-verilator-4.032-1-any.pkg.tar.xz
   
   # Add C:\msys64\usr\bin;C:\msys64\mingw64\bin to your Windows PATH
   
From source
~~~~~~~~~~~

.. code-block:: sh

   pacman -Syuu
   # Close the MSYS2 shell once you're asked to
   pacman -Syuu
   pacman -S --needed base-devel mingw-w64-x86_64-toolchain \
                      git flex\
                      mingw-w64-x86_64-cmake

   git clone http://git.veripool.org/git/verilator  
   unset VERILATOR_ROOT
   cd verilator
   git pull        
   git checkout v4.040
   autoconf      
   ./configure
   export CPLUS_INCLUDE_PATH=/usr/include:$CPLUS_INCLUDE_PATH
   export PATH=/usr/bin/core_perl:$PATH
   cp /usr/include/FlexLexer.h ./src

   make -j$(nproc)
   make install
   echo "DONE"
   # Add C:\msys64\usr\bin;C:\msys64\mingw64\bin to your Windows PATH

.. important::
   Be sure that your ``PATH`` environnement variable is pointing to the JDK 1.8 and doesn't contain a JRE installation.

.. important::
   Adding the MSYS2 ``bin`` folders into your windows ``PATH`` could potentialy have some side effects.
   This is why it is safer to add them as the last elements of the ``PATH`` to reduce their priority.