Python environment for Arm FVPs.

Arm FVPs require an installation of Python 3.9 for running the Python virtual interfaces. If you are using a Windows machine you can use an embedded Python installation in FVPs root directory, otherwise a system installation is required. Additional Python packages can be added using pip. In case you are using embedded Python installation see section: Install additional packages in embedded Python

Python requirements

The following packages are required on Linux systems (Ubuntu 20.04 and later):

libatomic1
libpython3.9
python3-pip

Run the following command to install required packages on Ubuntu:

sudo apt install libatomic1 libpython3.9 python3-pip

Install additional packages in embedded Python

By default the embedded Python installation on Windows does not support installation of new packages using pip. To enable installing new packages follow the steps described below.

Download get-pip.py to the FVPs root directory.
Uncomment the following line in the python39._pth file.
import site
Open command prompt in the FVPs root directory and run the following command.
.\python.exe get-pip.py
Install new packages using:
.\python.exe -m pip install <package>

The packages will be installed in Lib\site-packages subfolder.

Known issues

Some Python packages can't be imported directly in the Python virtual interfaces, because they are incompatible with Python sub-interpreters (e.g. numpy). Possible workaround for this issue is to split the Python module into client and server scripts.
Fast Models (Version 11.22.39) available through vcpkg include a stripped-down version of libpython3.9 library on Linux systems. This can cause the Fast Model to close with an error (VSI:Video:ImportError: No module named '_posixsubprocess') when running applications with VSI.
Current workaround:
- Rename or remove included libpython3.9.so.1.0 file, located in the vcpkg installation folder
  (e.g. ~/.vcpkg/artifacts/fd3d78d7/models.arm.avh.fvp/11.22.39/bin/models).
- Install libpython3.9 using the system package manager.