Initial Repository Setup
========================================================

Requirements
-------------------------------------------

Chipyard is developed and tested on Linux-based systems.

.. Warning:: It is possible to use this on macOS or other BSD-based systems, although GNU tools will need to be installed; it is also recommended to install the RISC-V toolchain from ``brew``.

.. Warning:: Working under Windows is not recommended.


In CentOS-based platforms, we recommend installing the following dependencies:

.. include:: /../scripts/centos-req.sh
   :code: bash

In Ubuntu/Debian-based platforms (Ubuntu), we recommend installing the following dependencies:

.. include:: /../scripts/ubuntu-req.sh
   :code: bash

.. Note:: When running on an Amazon Web Services EC2 FPGA-development instance (for FireSim), FireSim includes a machine setup script that will install all of the aforementioned dependencies (and some additional ones).

Setting up the Chipyard Repo
-------------------------------------------

Start by fetching Chipyard's sources. Run:

.. code-block:: shell

    git clone https://github.com/ucb-bar/chipyard.git
    cd chipyard
    ./scripts/init-submodules-no-riscv-tools.sh

This will initialize and checkout all of the necessary git submodules.

When updating Chipyard to a new version, you will also want to rerun this script to update the submodules.
Using git directly will try to initialize all submodules; this is not recommended unless you expressly desire this behavior.

.. _build-toolchains:

Building a Toolchain
------------------------

The `toolchains` directory contains toolchains that include a cross-compiler toolchain, frontend server, and proxy kernel, which you will need in order to compile code to RISC-V instructions and run them on your design.
Currently there are two toolchains, one for normal RISC-V programs, and another for Hwacha (``esp-tools``).
For custom installations, Each tool within the toolchains contains individual installation procedures within its README file.
To get a basic installation (which is the only thing needed for most Chipyard use-cases), just the following steps are necessary.
This will take about 20-30 minutes. You can expedite the process by setting a ``make`` environment variable to use parallel cores: ``export MAKEFLAGS=-j8``.

.. code-block:: shell

    ./scripts/build-toolchains.sh riscv-tools # for a normal risc-v toolchain

.. Note:: If you are planning to use the Hwacha vector unit, or other RoCC-based accelerators, you should build the esp-tools toolchain by adding the ``esp-tools`` argument to the script above.
  If you are running on an Amazon Web Services EC2 instance, intending to use FireSim, you can also use the ``--ec2fast`` flag for an expedited installation of a pre-compiled toolchain.

Once the script is run, a ``env.sh`` file is emitted that sets the ``PATH``, ``RISCV``, and ``LD_LIBRARY_PATH`` environment variables.
You can put this in your ``.bashrc`` or equivalent environment setup file to get the proper variables, or directly include it in your current environment:

.. code-block:: shell

    source ./env.sh

These variables need to be set for the ``make`` system to work properly.

What's Next?
-------------------------------------------

This depends on what you are planning to do with Chipyard.

* If you intend to run a simulation of one of the vanilla Chipyard examples, go to :ref:`sw-rtl-sim-intro` and follow the instructions.

* If you intend to run a simulation of a custom Chipyard SoC Configuration, go to :ref:`Simulating A Custom Project` and follow the instructions.

* If you intend to run a full-system FireSim simulation, go to :ref:`firesim-sim-intro` and follow the instructions.

* If you intend to add a new accelerator, go to :ref:`customization` and follow the instructions.

* If you want to learn about the structure of Chipyard, go to :ref:`chipyard-components`.

* If you intend to change the generators (BOOM, Rocket, etc) themselves, see :ref:`generator-index`.

* If you intend to run a tutorial VLSI flow using one of the Chipyard examples, go to :ref:`tutorial` and follow the instructions.

* If you intend to build a chip using one of the vanilla Chipyard examples, go to :ref:`build-a-chip` and follow the instructions.
