UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity
OpenCloudOS-Kernel/Documentation/arm/uefi.rst

71 lines
2.9 KiB
ReStructuredText
Raw Normal View History

docs: arm: convert docs to ReST and rename to *.rst Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-04-15 02:51:10 +08:00
================================================
The Unified Extensible Firmware Interface (UEFI)
================================================
doc: arm: add UEFI support documentation This patch provides documentation of the [U]EFI runtime service and configuration features for the arm architecture. Cc: Rob Landley <rob@landley.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-29 00:41:21 +08:00
UEFI, the Unified Extensible Firmware Interface, is a specification
governing the behaviours of compatible firmware interfaces. It is
maintained by the UEFI Forum - http://www.uefi.org/.
UEFI is an evolution of its predecessor 'EFI', so the terms EFI and
UEFI are used somewhat interchangeably in this document and associated
source code. As a rule, anything new uses 'UEFI', whereas 'EFI' refers
to legacy code or specifications.
UEFI support in Linux
=====================
Booting on a platform with firmware compliant with the UEFI specification
makes it possible for the kernel to support additional features:
docs: arm: convert docs to ReST and rename to *.rst Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-04-15 02:51:10 +08:00
doc: arm: add UEFI support documentation This patch provides documentation of the [U]EFI runtime service and configuration features for the arm architecture. Cc: Rob Landley <rob@landley.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-29 00:41:21 +08:00
- UEFI Runtime Services
- Retrieving various configuration information through the standardised
interface of UEFI configuration tables. (ACPI, SMBIOS, ...)
For actually enabling [U]EFI support, enable:
docs: arm: convert docs to ReST and rename to *.rst Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-04-15 02:51:10 +08:00
doc: arm: add UEFI support documentation This patch provides documentation of the [U]EFI runtime service and configuration features for the arm architecture. Cc: Rob Landley <rob@landley.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-29 00:41:21 +08:00
- CONFIG_EFI=y
efi: efivars: limit availability to X86 builds CONFIG_EFI_VARS controls the code that exposes EFI variables via sysfs entries, which was deprecated before support for non-Intel architectures was added to EFI. So let's limit its availability to Intel architectures for the time being, and hopefully remove it entirely in the not too distant future. While at it, let's remove the module alias so that the module is no longer loaded automatically. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-23 16:20:10 +08:00
- CONFIG_EFIVAR_FS=y or m
doc: arm: add UEFI support documentation This patch provides documentation of the [U]EFI runtime service and configuration features for the arm architecture. Cc: Rob Landley <rob@landley.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-29 00:41:21 +08:00
The implementation depends on receiving information about the UEFI environment
in a Flattened Device Tree (FDT) - so is only available with CONFIG_OF.
UEFI stub
=========
The "stub" is a feature that extends the Image/zImage into a valid UEFI
PE/COFF executable, including a loader application that makes it possible to
load the kernel directly from the UEFI shell, boot menu, or one of the
lightweight bootloaders like Gummiboot or rEFInd.
The kernel image built with stub support remains a valid kernel image for
booting in non-UEFI environments.
UEFI kernel support on ARM
==========================
UEFI kernel support on the ARM architectures (arm and arm64) is only available
when boot is performed through the stub.
When booting in UEFI mode, the stub deletes any memory nodes from a provided DT.
Instead, the kernel reads the UEFI memory map.
The stub populates the FDT /chosen node with (and the kernel scans for) the
following parameters:
docs: arm: convert docs to ReST and rename to *.rst Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-04-15 02:51:10 +08:00
========================== ====== ===========================================
Name Size Description
========================== ====== ===========================================
linux,uefi-system-table 64-bit Physical address of the UEFI System Table.
linux,uefi-mmap-start 64-bit Physical address of the UEFI memory map,
populated by the UEFI GetMemoryMap() call.
linux,uefi-mmap-size 32-bit Size in bytes of the UEFI memory map
pointed to in previous entry.
linux,uefi-mmap-desc-size 32-bit Size in bytes of each entry in the UEFI
memory map.
linux,uefi-mmap-desc-ver 32-bit Version of the mmap descriptor format.
docs: arm: /chosen node parameters Add missing items to table of parameters set in the /chosen node by the EFI stub. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Link: https://lore.kernel.org/r/20210206084120.43305-1-xypron.glpk@gmx.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-02-06 16:41:20 +08:00
kaslr-seed 64-bit Entropy used to randomize the kernel image
base address location.
docs: arm: convert docs to ReST and rename to *.rst Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-04-15 02:51:10 +08:00
========================== ====== ===========================================