1Trusted Firmware-A 2================== 3 4Trusted Firmware-A (TF-A) is a reference implementation of secure world software 5for `Arm A-Profile architectures`_ (Armv8-A and Armv7-A), including an Exception 6Level 3 (EL3) `Secure Monitor`_. It provides a suitable starting point for 7productization of secure world boot and runtime firmware, in either the AArch32 8or AArch64 execution states. 9 10TF-A implements Arm interface standards, including: 11 12- `Power State Coordination Interface (PSCI)`_ 13- `Trusted Board Boot Requirements CLIENT (TBBR-CLIENT)`_ 14- `SMC Calling Convention`_ 15- `System Control and Management Interface (SCMI)`_ 16- `Software Delegated Exception Interface (SDEI)`_ 17 18The code is designed to be portable and reusable across hardware platforms and 19software models that are based on the Armv8-A and Armv7-A architectures. 20 21In collaboration with interested parties, we will continue to enhance TF-A 22with reference implementations of Arm standards to benefit developers working 23with Armv7-A and Armv8-A TrustZone technology. 24 25Users are encouraged to do their own security validation, including penetration 26testing, on any secure world code derived from TF-A. 27 28More Info and Documentation 29--------------------------- 30 31To find out more about Trusted Firmware-A, please `view the full documentation`_ 32that is available through `trustedfirmware.org`_. 33 34-------------- 35 36*Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.* 37 38.. _Armv7-A and Armv8-A: https://developer.arm.com/products/architecture/a-profile 39.. _Secure Monitor: http://www.arm.com/products/processors/technologies/trustzone/tee-smc.php 40.. _Power State Coordination Interface (PSCI): PSCI_ 41.. _PSCI: https://developer.arm.com/documentation/den0022/latest 42.. _Trusted Board Boot Requirements CLIENT (TBBR-CLIENT): https://developer.arm.com/docs/den0006/latest 43.. _SMC Calling Convention: https://developer.arm.com/documentation/den0028/latest 44.. _System Control and Management Interface (SCMI): SCMI_ 45.. _SCMI: https://developer.arm.com/documentation/den0056/latest 46.. _Software Delegated Exception Interface (SDEI): SDEI_ 47.. _SDEI: https://developer.arm.com/documentation/den0054/latest 48.. _Arm A-Profile architectures: https://developer.arm.com/architectures/cpu-architecture/a-profile 49.. _view the full documentation: https://www.trustedfirmware.org/docs/tf-a 50.. _trustedfirmware.org: http://www.trustedfirmware.org 51 52