b07de0974b
(This is a replacement for commit 75136b29541b, "OvmfPkg/PlatformPei:
reorder the 32-bit PCI window vs. the PCIEXBAR on q35", 2019-05-16).
Commit 7b8fe63561b4 ("OvmfPkg: PlatformPei: enable PCIEXBAR (aka MMCONFIG
/ ECAM) on Q35", 2016-03-10) claimed that,
On Q35 machine types that QEMU intends to support in the long term, QEMU
never lets the RAM below 4 GB exceed 2 GB.
Alas, this statement came from a misunderstanding that occurred while we
worked out the interface contract. In fact QEMU does allow the 32-bit RAM
extend up to 0xB000_0000 (exclusive), in case the RAM size falls in the
range (0x8000_0000, 0xB000_0000) (i.e., the RAM size is greater than
2048MB and smaller than 2816MB).
In turn, such a RAM size (justifiedly) triggers
ASSERT (TopOfLowRam <= PciExBarBase);
in MemMapInitialization(), because we placed the 256MB PCIEXBAR at
0x8000_0000 (2GB) exactly, relying on the interface contract. (And, the
32-bit PCI window would follow the PCIEXBAR, covering the [0x9000_0000,
0xFC00_0000) range.)
In order to fix this, place the PCIEXBAR at 2816MB (0xB000_0000), and
start the 32-bit PCI window at 3 GB (0xC000_0000). This shrinks the 32-bit
PCI window to
0xFC00_0000 - 0xC000_0000 = 0x3C00_0000 = 960 MB.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1859
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
EDK II Project
A modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications from www.uefi.org.
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
- EdkCompatibilityPkg/Other/Maintained/Tools/Pccts
- MdeModulePkg/Universal/RegularExpressionDxe/Oniguruma
- OvmfPkg
- CryptoPkg/Library/OpensslLib/openssl
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
- UDK2017
- UDK2018
- edk2-stable201811
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.