Embedded Base Boot Requirements (EBBR) specification

The Embedded Base Boot Requirements specification defines requirements for embedded systems to enable inter-operability between SoCs, hardware platforms, firmware implementations, and operating system distributions. The aim is to establish consistent boot ABIs and behaviour so that supporting new hardware platforms does not require custom engineering work.

The first formal v1.0 release of EBBR was made in March 2019. You can find the current draft text in this repository, but be aware that everything in the draft text is subject to change. Official pdfs can be found in the "Releases" tab of this GitHub project.

Released EBBR PDFs can be found here:

https://github.com/ARM-software/ebbr/releases

The latest development version is available at:

https://ARM-software.github.io/ebbr/

Contributing

Anyone may contribute to EBBR. Discussion is on the boot-architecture@lists.linaro.org mailing list, and there is a weekly conference call. See CONTRIBUTING.rst for details.

Build Instructions

Requirements

• Sphinx version 1.5 or later: http://sphinx-doc.org/en/master/contents.html
• LaTeX (and pdflatex, and various LaTeX packages)
• Optionally, for verification: flake8, mypy and yamllint

On Debian and Ubuntu

# apt-get install python3-sphinx texlive texlive-latex-extra \
                  libalgorithm-diff-perl texlive-humanities \
                  texlive-generic-recommended texlive-generic-extra \
                  latexmk

If the version of python-sphinx installed is too old, then an additional new version can be installed with the Python package installer:

$ apt-get install python3-pip
$ pip3 install --user --upgrade Sphinx
$ export SPHINXBUILD=~/.local/bin/sphinx-build

Export SPHINXBUILD (see above) if Sphinx was installed with pip3 --user, then follow Make commands below.

Note: the .github/workflows/main.yaml CI configuration file installs the necessary dependencies for Ubuntu and can be used as an example.

On Fedora

# dnf install python3-sphinx texlive texlive-capt-of texlive-draftwatermark \
              texlive-fncychap texlive-framed texlive-needspace \
              texlive-tabulary texlive-titlesec texlive-upquote \
              texlive-wrapfig texinfo latexmk

On Mac OS X

• Install MacTeX

• Install pip if you do not have it:

  $ sudo easy_install pip
  

• Install Sphinx:

  $ pip install --user --upgrade Sphinx
  

Make Targets

To generate PDF:

$ make latexpdf

To generate hierarchy of HTML pages:

$ make html

To generate a single HTML page:

$ make singlehtml

To generate as text (useful for comparing different versions):

$ make text

Output goes in ./build subdirectory.

To run verifications on this repository:

$ make check

To get some help on the available targets:

$ make help

License

This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License (CC-BY-SA-4.0). To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Contributions are accepted under the same with sign-off under the Developer's Certificate of Origin. For more on contributing to EBBR, see CONTRIBUTING.rst.

A copy of the license is included in the LICENSE file.

Writers Guide

All documentation in this repository uses reStructuredText markup with Sphinx extensions.

All files in this project must include the relevant SPDX license identifier tag. Generally this means each .rst file should include the line

.. SPDX-License-Identifier: CC-BY-SA-4.0

In general, try to keep the text width to at most 80 columns. Try to write footnotes contents as close a possible to the places referencing them.

Sphinx Extensions

Sphinx extension files are kept under source/extensions/.

Debugging extensions is easier when running Sphinx with debug messages:

$ make singlehtml SPHINXOPTS=-vv

UEFI chapter links

We have an extension for referencing UEFI specifications chapters.

To reference UEFI section 6.1 for example, write:

:UEFI:`6.1`

This will be expanded to the following reference, with a link to the UEFI webpage:

UEFI § 6.1 Block Translation Table (BTT) Background

We keep the UEFI index .csv file under version control for caching, and we have a python script to re-generate it from the UEFI specification webpage. To re-generate the index file, do:

$ ./scripts/update_uefi_index.py

Original Document

Prior to being relicensed to CC-BY-SA 4.0, this specification was released by Arm. The original Draft v0.5 text can be found here:

EBBR Draft v0.5