"Arm Trusted Firmware provides a reference implementation of secure world software for Armv8-A and Armv8-M. It provides SoC developers and OEMs with a reference trusted code base complying with the relevant Arm specifications. The code on this website is the preferred implementation of Arm specifications, allowing quick and easy porting to modern chips and platforms. This forms the foundations of a Trusted Execution Environment (TEE) on application processors, or the Secure Processing Environment (SPE) of microcontrollers."
Trusted Firmware-A targets Armv8-A SoCs; see Trusted Firmware-M for Armv8-M SoCs.
The Trusted Firmware project is adopting open governance:
You can install and run Trusted Firmware-A on some platforms as part of the reference software stacks shipped with the Arm Reference Platforms deliverables.
Alternatively, follow the official user guide.