OpenSPARC Frequently Asked Questions

Back to OpenSPARC Overview
  • General
    • How does the OpenSPARC project model differ from other models for processor cores?
      We are not aware of any other major company that posts 64-bit, multi-threaded processor core IP on a Web site where anyone can download it under an OSI-Approved open source license.
    • Is there any cost to using the code?
      No. There are no fees associated with downloading the code from this site for use under GPL 2 license.
    • What are the benefits to developers?
    • What is "Open Source" Hardware?
      The term "Open Source" today most often refers to "Free/Libre or Open Source Software, (FL/OSS)." While it is not a perfect term in the hardware space, we consider "Open Source" as a reference, where we are providing under Open Source license free and open tools that are essential components to developing a new chip.
    • What is the OpenSPARC Project?
      OpenSPARC project is making the hardware source code of the UltraSPARC T1 and UltraSPARC T2 processors available under an Open Source license.
    • What open source licensing model are you using the code?
      We have selected GPL v2. See Licensing FAQs for more details.
    • What parts to the chip design are you "Open Sourcing?"
      The source of the design in Verilog, a verification suite and simulation models, ISA specification (UltraSPARC Architecture 2005), and a software simulation model for Solaris that gives developers a rapid means of developing and testing software functionality in the absense of actual hardware.
    • What role does SPARC International play in this?
      SPARC International was created in 1989 as an independent, non-profit organization. The Corporation's purpose is to promote the design, development, and application of SPARC (Scalable Processor ARChitecture) to computer and related products, and to control, maintain, and enforce SPARC trademarks. Sun has open-sourced an implementation of the SPARC architecture; the open-source implementation is independent of the oversight provided by SPARC International. SPARC International continues to provide SPARC compliance test suites to developers who wish to certify and brand their own implementation based on SPARC architectures. To become a SPARC International member, obtain information for compliance test suites, or to get answers to trademark questions contact:
  • Contributors Agreement
    • If I sign this once, does it apply to source code on all projects on the site?
      Yes. This agreement covers not only all projects on this site, but also applies to any project sponsored by Oracle that requires this agreement. Please retain a copy for your records, and to send to another project if you are asked.
    • More FAQ on Oracle Contributor Agreement (OCA):
    • What is the Contributors Agreement for?
      The OCA gives Oracle and the contributor joint copyright interests in the code. The contributor retains copyrights while also granting those rights to Oracle as the project sponsor.
    • Where do I send the Contributor Agreement to?
      An OCA can be remitted for acceptance by emailing a scanned, completed, signed copy to oracle-ca_us [at] oracle [dot] com. Or, you may use that email address to request a fax number for remittance of hard copy.
  • Licensing
    • Can Sun ever take away the OpenSPARC technology licensed under the GPLv2?
      No, once technology is licensed under the GPLv2, the technology remains licensed under the terms of the GPLv2.
    • Can I license my modified OpenSPARC technology under the GPLv2, as well as under another license?
      You should carefully review the terms of the GPLv2 with respect to your licensing obligations, but generally if you choose to distribute your modifications to others it must be released under the same terms as the original technology. So, the modifications you choose to distribute must be licensed under the GPLv2.
    • Can I redistribute or sell the OpenSPARC technology licensed under the GPLv2 with my modifications?
      Yes, you can modify and redistribute technology, including charging a fee for the distribution. However, you will need to meet the terms of the GPLv2, including making the RTL of your modified technology available under the GPLv2.
    • I want to get credit for my work and for people to know what I wrote - can I still get credit if I use the GPLv2?
      You can certainly get credit for your work. Part of releasing a program under the GPL is writing a copyright notice in your own name (assuming you are the copyright holder). The GPL require's all copies to carry an appropriate copyright notice, however you should not remove any copyright notices already embedded in the technology.
    • If I contribute technology which was licensed under the GPLv2 to the OpenSPARC project, what will I be asked to do as far as licensing is concerned?

      Technology licensed under the GPLv2 which you contribute to the OpenSPARC project must be made available under the GPLv2. We're working out the details of the code submission process. In addition, you must have submitted a contributor agreement. The OCA is available here: .

    • If I distribute OpenSPARC technology licensed under the GPLv2 in my proprietary product, will I have to share my RTL?
      Yes, for any technology licensed under the GPLv2 and any modifications you make you must share. Review the terms of the GPLv2 to determine if you have additional obligations.
    • May I take portions of the OpenSPARC technology licensed under the GPLv2 and use it in another project?
      You can only do so if you comply with the terms of the GPLv2.
    • Why was the BSD license chosen for some of the OpenSPARC technology?
      Sun chose the BSD for certain technologies in order to make them more broadly available to multiple open source communities such as FreeBSD and OpenSolaris.
    • Why was the GPLv2 chosen as the license for the T1 processor Register Transfer Language (RTL)?
      Sun wanted to release T1 processor RTL under the GPLv2 so that the community would have access to processor technology under an open source license. The GPLv2 gives user the freedom to run, copy, distribute, study, change and improve the technology. More precisely, it refers to four kinds of freedom, for the users of the technology:
      • The freedom to use the technology for any purpose.
      • The freedom to study how the technology works, and adapt it to your needs.
      • The freedom to redistribute copies so you can help others in the community.
      • The freedom to improve the technology, and release your improvements to the public, so that the whole community benefits.

      The GPLv2 meets the requirements of the Open Source Definition ( and has been approved as an open source license by the Open Source Initiative (

    • Will all of the T1 and T2 processors RTL technology be released under the GPLv2?
      The OpenSPARC T1 and T2 processors RTL were released under the GPLv2. In order to promote compatibility with a variety of communities (Linux, FreeBSD and OpenSolaris), some technology and tools will be made available under a BSD license. Other technology (particularly code contributed by third parties and certain tools) will only be available as binaries will only be available under a binary Software License Agreement. Finally, some components may be based on existing open source projects and these will be made available on the OpenSPARC website under their current licenses.
  • Technical
    • Can I use Verilog simulator other than VCS or NC-Verilog ?
      Yes, you can use any Verilog Simulator, but please make sure to follow instructions to compile and link PLI C/C++ code, and specify correct parameters to the Simulation script.
      • Design Compiler®, VCS®, Vera® are registered trademarks of Synopsys, Inc.
      • NC-Verilog® is registered trademark of Cadence, Inc.
      • Debussy® is registered trademark of Novas, Inc.
    • What are some distinguishing characteristics of OpenSPARC T1 and T2?
      • The premier general-purpose microprocessor designs in the computer industry today
      • The only open-source 64-bit processors in the world
      • The only open-source Chip Multi-Threaded (CMT) processors in the world
      • Modern, real (not "toy") designs - OpenSPARC can boot real off-the-shelf commercial operating systems (e.g.Solaris, Linux, FreeBSD, OpenBSD) and run off-the-shelf application software
      • Backed by a growing open-source community
      • 14 million lines of code open-sourced in OpenSPARC T1 and 41 million lines of code open-sourced in OpenSPARG T2!
    • What are the commercial EDA tools needed to use the OpenSPARC T1 source code?

      Once you download the source code, to run simulations of the OpenSPARC T1 you will need the following:

      • A Verilog Simulator - VCS® from Synopsys or NC-Verilog® from Cadence or Rivera® from Aldec
      • Optionally, Vera® compiler and run time libraries from Synopsys.
      • Optionally, Debussy® debug system from Novas for simulation debugging.

      To run Synthesis of OpenSPARC T1, you will need:

      • Design Compiler® from Synopsys.
      • Your silicon fab vendor's synthesis libraries.

      To run FPFGA Synthesis of OpenSPARC T1, you will need:

      • Synplify Pro® from Synplicity.
    • What are the differences between OpenSPARC T1 and UltraSPARC T1? 
      OpenSPARC T1 source code is modified from the original source code of UltraSPARC T1. Every attempt is made to keep the OpenSPARC T1 source as close to the original UltraSPARC T1 in the process of preparing it for release in a standalone environment and preparing it to comply with the legal requirements. OpenSPARC T2 has the same differences.
    • What are the system requirements to use OpenSPARC T1 source code?
      Once you download the source code, you can run Verilog simulation, RTL synthesis, Architecture and Performance modeling tools on any SPARC system with Solaris 9 or Solaris 10 operating system.
    • What is available with/for OpenSPARC T1 and T2?
      • Full source code to the UltraSPARC implementation (cores/pipelines/threads: T1=8/8/32, T2 = 8/16/64)
      • Full source code to a reduced UltraSPARC T1 implementation (1 core, 1 thread) which has been optimized for synthesis into FPGAs
      • Software tools (compilers, simulators)
      • Verfication suite
      • UltraSPARC Architecture 2005(2007) specifications, UltraSPARC T1(T2) Implementation Supplements
      • Operating systems already ported to work on OpenSPARC:Solaris 10, three distributions of Linux (Ubuntu, Gentoo, ...), and FreeBSD
    • What is included in the OpenSPARC T1 download?

      OpenSPARC T1 Download for the Chip Design and Verification includes:

      • Chip Design source code in Verilog language.
      • Verification test benches source code in Verilog, Vera®, PLI code in C and C++.
      • Verification tests source code in SPARC assembly language.
      • Scripts needed to assemble and run tests on the design using verification test benches.
      • Synthesis scripts for Synopsys Design Compiler®.
      • SPARC Architecture Simulator (SAS).
      • Documentation.

      OpenSPARC T1 Download for Architecture and Performance modeling includes:

      • SAM - SPARC Architecture Model
      • Legion - Fast instruction accurate simulator for software developers
      • SPARC Architecture Simulator (SAS).
      • Solaris image for simulation.
      • Documentation.
Jouer dans un casino en ligne est amusant, mais il exige également que vous trouverez des faits au sujet du casino, vous devriez jouer. Ici, au nous avons accumulé plusieurs années d'expérience onlincasinos. Nous vous recommandons de ne jouer au casino en ligne qui peuvent offrir les dernières technologies et un soutien à la clientèle qui répondra à vos questions en temps opportun. Un casino en ligne doit être immatriculé et divulguer publiquement cela et leurs paiements.