The current TF-A buildsystem became too complex and rigid, a new buildsystem using CMake is proposed. This document provides a summary about how we plan to introduce the buildsystem related changes to TF-A. For technical details, please check https://review.trustedfirmware.org/#/c/TF-A/trusted-firmware-a/+/2662/
The migration of the TF-A buildsystem is a long and complex process, to make it more manageable, the plan is to split to two phases:
- Feasibility study and prototyping.
- Create a build-system framework based on cmake.
- Imlement build solution for TF-A using the framework.
- No source code modification.
- No project structure modification.
In the first phase the focus is on the framework and the project source code is unchanged. Therefore the buildsystem logic will be similar to the current Makefile based, the full potential of CMake is not used.
- Enhancement of TF-A structure.
- Source code refactoring to enhance flexibility.
- Better modularization, clear APIs and dependencies
- Build framework enhancements.
Some parts of the TF-A source code are currently monolithic, with no clear modules and dependencies defined. In the second phase this can also be refactored, to make the project more flexible. CMake allows easy modularization (e.g. transitive dependency handling, etc...). This also causes that some changes are necessary to the framework.
The following diagram describes the planned timeline: