# Getting Started

Welcome!

This guide will help you get OpenTitan up and running by instructing you how to:

2. clone the OpenTitan Git repository, and
3. build OpenTitan software/hardware for the target of your choosing.

As shown in the diagram above, we currently support multiple build targets and workflows, including: Verilator, FPGA, and DV. However, if you are new to the project, we recommend simulation with Verilator, as this uses only free EDA tools, and does not require any additional hardware.

## Environment Setup

There are two choices for setting up an OpenTitan environment:

1. [Supported] manual installation, or
2. [Experimental] provided Docker container.

While the first option is the only one currently supported, the second option is the quickest to get running. If you plan on being a long term user of the project, and/or contributer, we recommend the first (manual installation) option. Alternatively, if your goal is to get a Verilator simulation up and running as quickly as possible, you may find it easier to try the second (container) option.

## Cloning the OpenTitan Repository

The OpenTitan Repository must be checked out locally. If you wish to contribute to OpenTitan you will need to make a fork on GitHub, otherwise you can just locally clone the main repository. There are a set of notes for using GitHub which explains how to work with your own fork.

Note: throughout the documentation \$REPO_TOP refers to the path where the OpenTitan repository is checked out.

## Building OpenTitan Software/Hardware

Once you have setup a suitable environment and cloned the OpenTitan source code, you need to choose a top-level OpenTitan design to build. The code base contains multiple top-level designs, which can be synthesized or simulated. A target can be a simulation tool, an FPGA board, or an ASIC technology. We currently support two out of the three aformentioned target types (i.e., simulation tools and FPGA), as described in this table:

Verilator Simulation Tool SW Testing no no Getting Started with Verilator
FPGA FPGA Board Testing & Evaluation maybe (FPGA size dependent) yes Getting Started on FPGAs
DV Simulation Tool HW Verification yes no Getting Started with Design Verification

The instructions on how to compile the required demo software, and synthesize the main top-level hardware design (Earl Grey) for each target are linked above in the table. Again, if you are new to the project, we recommend starting with the Verilator target, as this uses only free EDA tools, and does not require any additional hardware.