OpenROAD Flow

Introduction

The OpenROAD (“Foundations and Realization of Open, Accessible Design”) project was launched in June 2018 within the DARPA IDEA program. OpenROAD aims to bring down the barriers of cost, expertise and unpredictability that currently block designers’ access to hardware implementation in advanced technologies. The project team (Qualcomm, Arm and multiple universities and partners, led by UC San Diego) is developing a fully autonomous, open-source tool chain for digital layout generation across die, package and board, with initial focus on the RTL-to-GDSII phase of system-on-chip design. Thus, OpenROAD holistically attacks the multiple facets of today’s design cost crisis: engineering resources, design tool licenses, project schedule, and risk.

The IDEA program targets no-human-in-loop (NHIL) design, with 24-hour turnaround time and eventual zero loss of power-performance-area (PPA) design quality. No humans means that tools must adapt and self-tune, and never get stuck: thus, machine intelligence must replace today’s human intelligence within the layout generation process. 24 hours means that problems must be aggressively decomposed into bite-sized subproblems for the design process to remain within the schedule constraint. Eventual zero loss of PPA quality requires parallel and distributed search to recoup the solution quality lost by problem decomposition.

For a technical description of the OpenROAD flow, please refer to our DAC paper: Toward an Open-Source Digital Flow: First Learnings from the OpenROAD Project. Also, available from ACM Digital Library (doi:10.1145/3316781.3326334)

Code Organization

This repository serves as an example RTL-to-GDS flow using the OpenROAD tools. The two main components are:

1. tools: This directory contains the source code for the entire openroad app (via submodules) as well as other tools required for the flow. The script build_openroad.sh in this repository will automatically build the OpenROAD toolchain.

2. flow: This directory contains reference recipes and scripts to run | designs through the flow. It also contains platforms and test designs.

Setup

The flow has the following dependencies:

• OpenROAD
• KLayout
• TritonRoute
• Yosys

The dependencies can either be obtained from a pre-compiled build export or built manually. See the KLayout website for installation instructions.

Option 1: Installing build exports

1. Clone the OpenROAD-flow repository

git clone --recursive https://github.com/The-OpenROAD-Project/OpenROAD-flow.git

2. Navigate to the “Releases” tab and download the latest release
3. Extract the tar to OpenROAD-flow/tools/OpenROAD
4. Update your shell environment

source setup_env.sh

Option 2: Building the tools using docker

This build option leverages a multi-step docker flow to install the tools and dependencies to a runner image. To follow these instructions, you must have docker installed, permissions to run docker, and docker container network access enabled. This step will create a runner image tagged as openroad/flow.

1. Clone the OpenROAD-flow repository

git clone --recursive https://github.com/The-OpenROAD-Project/OpenROAD-flow.git

2. Ensure your docker daemon is running and docker is in your PATH, then run the docker build.

./build_openroad.sh

3. Start an interactive shell in a docker container using your user credentials

docker run -it -u $(id -u ${USER}):$(id -g ${USER}) openroad/flow bash

Option 3: Building the tools locally

1. Reference the Dockerfiles and READMEs for the separate tools on the build steps and dependencies.

OpenROAD-flow/tools/OpenROAD/Dockerfile
OpenROAD-flow/tools/yosys/Dockerfile
OpenROAD-flow/tools/TritonRoute/Dockerfile

See the KLayout instructions for installing KLayout from source.

2. Run the build script

./build_openroad.sh

3. Update your shell environment

source setup_env.sh

klayout must be added to the path manually.

Using the flow

See the flow README for details about the flow and how to run designs through the flow

Useful Resources

Your feedback is very welcome.

• Website: Visit our website for more information on the project, participants and objectives.
• GitHub Issues: Please submit GitHub issues for any bugs, improvements, or new feature requests. Feedback can be directed at this repository or the repository for the tool, component or design as appropriate. This link is an aggregate of all OpenROAD related issues
• Community: Find us on the public Gitter community where you can ask quick questions or discuss anything OpenROAD related.
• Twitter: Follow us on twitter - @OpenROAD_EDA.

Contributing

We welcome any comments, patches and designs to help us improve the tool. At this time we are focused on overhauling the build process, build testing, and the continuous integration framework. This will set us up for better integration with contributors. Please stay tuned.

License

The OpenROAD-flow repository (build and run scripts) has a BSD 3-Clause License. The flow relies on several tools, platforms and designs that each have their own licenses:

• Find the tool license at: OpenROAD-flow/tools/{tool}/ or OpenROAD-flow/tools/OpenROAD/src/{tool}/
• Find the platform license at: OpenROAD-flow/flow/platforms/{platform}/
• Find the design license at: OpenROAD-flow/flow/designs/src/{design}/