2.2. Building Documentation

To create a rendered copy of this documentation locally you can use the Sphinx tool to build and package the plain-text documents into HTML-formatted pages.

If you are building the documentation for the first time then you will need to check that you have the required software packages, as described in the Prerequisites section that follows.

Note

An online copy of the documentation is available at https://www.trustedfirmware.org/docs/tf-a, if you want to view a rendered copy without doing a local build.

2.2.1. Prerequisites

For building a local copy of the TF-A documentation you will need:

Python 3 (3.8 or later)
PlantUML (1.2017.15 or later)
Poetry (Python dependency manager)
Optionally, the Dia application can be installed if you need to edit existing .dia diagram files, or create new ones.

Below is an example set of instructions to get a working environment (tested on Ubuntu):

sudo apt install python3 python3-pip plantuml [dia]
curl -sSL https://install.python-poetry.org | python3 -

2.2.2. Building rendered documentation

To install Python dependencies using Poetry:

poetry install

Poetry will create a new virtual environment and install all dependencies listed in pyproject.toml. You can get information about this environment, such as its location and the Python version, with the command:

poetry env info

If you have already sourced a virtual environment, Poetry will respect this and install dependencies there.

Once all dependencies are installed, the documentation can be compiled into HTML-formatted pages from the project root directory by running:

poetry run make doc

Output from the build process will be placed in: docs/build/html.

2.2.2.1. Other Output Formats

We also support building documentation in other formats. From the docs directory of the project, run the following command to see the supported formats.

poetry run make -C docs help

2.2.2.2. Building rendered documentation from Poetry’s virtual environment

The command poetry run used in the steps above executes the input command from inside the project’s virtual environment. The easiest way to activate this virtual environment is with the poetry shell command.

Running poetry shell from the directory containing this project, activates the same virtual environment. This creates a sub-shell through which you can build the documentation directly with make.

poetry shell
make doc

Type exit to deactivate the virtual environment and exit this new shell. For other use cases, please see the official Poetry documentation.

2.2.3. Building rendered documentation from a container

There may be cases where you can not either install or upgrade required dependencies to generate the documents, so in this case, one way to create the documentation is through a docker container. The first step is to check if docker is installed in your host, otherwise check main docker page for installation instructions. Once installed, run the following script from project root directory

docker run --rm -v $PWD:/tf-a sphinxdoc/sphinx \
     bash -c 'cd /tf-a &&
         apt-get update && apt-get install -y curl plantuml &&
         curl -sSL https://install.python-poetry.org | python3 - &&
         ~/.local/bin/poetry install && ~/.local/bin/poetry run make doc'

The above command fetches the sphinxdoc/sphinx container from docker hub, launches the container, installs documentation requirements and finally creates the documentation. Once done, exit the container and output from the build process will be placed in: docs/build/html.