Skip to content
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
Cannot retrieve contributors at this time

EDK II Project

A modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications from

Core CI Build Status

Host Type & Toolchain Build Status Test Status Code Coverage
Windows_VS2019 WindowsCiBuild WindowsCiTest WindowsCiCoverage
Ubuntu_GCC5 UbuntuCiBuild UbuntuCiTest UbuntuCiCoverage

More CI Build information

Platform CI Build Status

Microsoft Windows VS2019

em32d em32r em32n

em64d em64r em64n

em32fd em32fr em32fn

em64fd em64fr em64fn
op32d op32r op32n

op64d op64r op64n

IA32 X64
op3264d op3264r op3264n

op3264fd op3264fr TCBZ_2661

Ubuntu 18.04 GCC5

avAArch64du avAArch64ru avAArch64nu

avArmdu avArmru avArmnu
em32du em32ru em32nu

em64du em64ru em64nu

em32fdu em32fru em32fnu

em64fdu em64fru em64fnu
op32du op32ru op32nu

op64du op64ru op64nu

IA32 X64
op3264du op3264ru op3264nu

op3264fdu op3264fru op3264fru

TCBZ_2668 - EmulatorPkg Ubuntu GCC5 Segfaults during execution.

TCBZ_2639 - EmulatorPkg Ubuntu GCC5 Segfaults during execution.

More ArmVirtPkg CI Build Information

More EmulatorPkg CI Build Information

More OvmfPkg CI Build Information

License Details

The majority of the content in the EDK II open source project uses a BSD-2-Clause Plus Patent License. The EDK II open source project contains the following components that are covered by additional licenses:

The EDK II open source project uses content from upstream projects as git submodules that are covered by additional licenses.

The EDK II Project is composed of packages. The maintainers for each package are listed in Maintainers.txt.


Code Contributions

To make a contribution to a TianoCore project, follow these steps.

  1. Create a change description in the format specified below to
    use in the source control commit log.
  2. Your commit message must include your Signed-off-by signature
  3. Submit your code to the TianoCore project using the process
    that the project documents on its web page. If the process is not documented, then submit the code on development email list for the project.
  4. It is preferred that contributions are submitted using the same
    copyright license as the base project. When that is not possible, then contributions using the following licenses can be accepted:

For documentation:

Contributions of code put into the public domain can also be accepted.

Contributions using other licenses might be accepted, but further review will be required.

Developer Certificate of Origin

Your change description should use the standard format for a commit message, and must include your Signed-off-by signature.

In order to keep track of who did what, all patches contributed must include a statement that to the best of the contributor's knowledge they have the right to contribute it under the specified license.

The test for this is as specified in the Developer's Certificate of Origin (DCO) 1.1. The contributor certifies compliance by adding a line saying

Signed-off-by: Developer Name

where Developer Name is the contributor's real name, and the email address is one the developer is reachable through at the time of contributing.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

Sample Change Description / Commit Message

From: Contributor Name <>
Subject: [Repository/Branch PATCH] Pkg-Module: Brief-single-line-summary


Signed-off-by: Contributor Name <>

Notes for sample patch email

  • The first line of commit message is taken from the email's subject line following [Repository/Branch PATCH]. The remaining portion of the commit message is the email's content.
  • git format-patch is one way to create this format

Definitions for sample patch email

  • Repository is the identifier of the repository the patch applies.

    This identifier should only be provided for repositories other than edk2. For example edk2-BuildSpecification or staging.

  • Branch is the identifier of the branch the patch applies. This

    identifier should only be provided for branches other than


    For example edk2/UDK2015,

    edk2-BuildSpecification/release/1.27, or


  • Module is a short identifier for the affected code or documentation. For example MdePkg, MdeModulePkg/UsbBusDxe, Introduction, or

    EDK II INF File Format.

  • Brief-single-line-summary is a short summary of the change.

  • The entire first line should be less than ~70 characters.

  • Full-commit-message a verbose multiple line comment describing

    the change. Each line should be less than ~70 characters.

  • Signed-off-by is the contributor's signature identifying them

    by their real/legal name and their email address.


Submodule in EDK II is allowed but submodule chain should be avoided as possible as we can. Currently EDK II contains the following submodules

  • CryptoPkg/Library/OpensslLib/openssl
  • ArmPkg/Library/ArmSoftFloatLib/berkeley-softfloat-3
  • MdeModulePkg/Universal/RegularExpressionDxe/oniguruma
  • MdeModulePkg/Library/BrotliCustomDecompressLib/brotli
  • BaseTools/Source/C/BrotliCompress/brotli

ArmSoftFloatLib is actually required by OpensslLib. It's inevitable in openssl-1.1.1 (since stable201905) for floating point parameter conversion, but should be dropped once there's no such need in future release of openssl.

To get a full, buildable EDK II repository, use following steps of git command

git clone
cd edk2
git submodule update --init
cd ..

If there's update for submodules, use following git commands to get the latest submodules code.

cd edk2
git pull
git submodule update

Note: When cloning submodule repos, '--recursive' option is not recommended. EDK II itself will not use any code/feature from submodules in above submodules. So using '--recursive' adds a dependency on being able to reach servers we do not actually want any code from, as well as needlessly downloading code we will not use.