6c9a3d4233
Cache maintenance operations by set/way are only intended to be used in the context of on/offlining a core, while it has been taken out of the coherency domain. Any use intended to ensure that the contents of the cache have made it to main memory is unreliable, since cacheline migration and non-architected system caches may cause these contents to linger elsewhere, without being visible in main memory once the MMU and caches are disabled. In KVM on Linux, there are horrid hacks in place to ensure that such set/way operations are trapped, and replaced with a single by-VA clean/invalidate of the entire guest VA space once the MMU state changes, which can be costly, and is unnecessary if we manage the caches a bit more carefully, and perform maintenance by virtual address only. So let's get rid of the call to ArmInvalidateDataCache () in the PrePeiCore startup code, and instead, invalidate the temporary RAM region by virtual address, which is the only memory region we will be touching with the caches and MMU both disabled and enabled, which will lead to data corruption if data written with the MMU off is shadowed by clean, stale cachelines that stick around when the MMU is enabled again. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com> Reviewed-by: Leif Lindholm <leif@nuviainc.com> Acked-by: Laszlo Ersek <lersek@redhat.com>
EDK II Project
A modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications from www.uefi.org.
Build Status
| Host Type | Toolchain | Branch | Build Status | Test Status | Code Coverage |
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| Windows | VS2019 | master |
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| Ubuntu | GCC | master |
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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:
- BaseTools/Source/C/BrotliCompress
- MdeModulePkg/Library/BrotliCustomDecompressLib
- BaseTools/Source/C/LzmaCompress
- MdeModulePkg/Library/LzmaCustomDecompressLib
- IntelFrameworkModulePkg/Library/LzmaCustomDecompressLib/Sdk
- BaseTools/Source/C/VfrCompile/Pccts
- MdeModulePkg/Universal/RegularExpressionDxe/Oniguruma
- OvmfPkg
- CryptoPkg/Library/OpensslLib/openssl
- ArmPkg/Library/ArmSoftFloatLib/berkeley-softfloat-3
The EDK II Project is composed of packages. The maintainers for each package are listed in Maintainers.txt.
Resources
- TianoCore
- EDK II
- Getting Started with EDK II
- Mailing Lists
- TianoCore Bugzilla
- How To Contribute
- Release Planning
Code Contributions
To make a contribution to a TianoCore project, follow these steps.
-
Create a change description in the format specified below to use in the source control commit log.
-
Your commit message must include your
Signed-off-bysignature -
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.
-
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:
- BSD (2-clause): http://opensource.org/licenses/BSD-2-Clause
- BSD (3-clause): http://opensource.org/licenses/BSD-3-Clause
- MIT: http://opensource.org/licenses/MIT
- Python-2.0: http://opensource.org/licenses/Python-2.0
- Zlib: http://opensource.org/licenses/Zlib
For documentation:
- FreeBSD Documentation License https://www.freebsd.org/copyright/freebsd-doc-license.html
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 developer@example.org
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
it.
(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 <contributor@example.com>
Subject: [Repository/Branch PATCH] Pkg-Module: Brief-single-line-summary
Full-commit-message
Signed-off-by: Contributor Name <contributor@example.com>
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-patchis one way to create this format
Definitions for sample patch email
Repositoryis the identifier of the repository the patch applies. This identifier should only be provided for repositories other thanedk2. For exampleedk2-BuildSpecificationorstaging.Branchis the identifier of the branch the patch applies. This identifier should only be provided for branches other thanedk2/master. For exampleedk2/UDK2015,edk2-BuildSpecification/release/1.27, orstaging/edk2-test.Moduleis a short identifier for the affected code or documentation. For exampleMdePkg,MdeModulePkg/UsbBusDxe,Introduction, orEDK II INF File Format.Brief-single-line-summaryis a short summary of the change.- The entire first line should be less than ~70 characters.
Full-commit-messagea verbose multiple line comment describing the change. Each line should be less than ~70 characters.Signed-off-byis the contributor's signature identifying them by their real/legal name and their email address.
Submodules
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
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 https://github.com/tianocore/edk2.git
$ 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.