arm-trusted-firmware



Trusted Firmware-A - version 2.0
Trusted Firmware-A (TF-A) provides a reference implementation of secure world
software for Armv7-A and Armv8-A, including a Secure Monitor executing
at Exception Level 3 (EL3). It implements various Arm interface standards,
such as:

The Power State Coordination Interface (PSCI)

Trusted Board Boot Requirements (TBBR, Arm DEN0006C-1)
SMC Calling Convention
System Control and Management Interface
Software Delegated Exception Interface (SDEI)

Where possible, the code is designed for reuse or porting to other Armv7-A and
Armv8-A model and hardware platforms.
Arm will continue development in collaboration with interested parties to
provide a full reference implementation of Secure Monitor code and Arm standards
to the benefit of all developers working with Armv7-A and Armv8-A TrustZone
technology.

License
The software is provided under a BSD-3-Clause license. Contributions to this
project are accepted under the same license with developer sign-off as
described in the Contributing Guidelines.
This project contains code from other projects as listed below. The original
license text is included in those source files.

The libc source code is derived from FreeBSD and SCC. FreeBSD uses
various BSD licenses, including BSD-3-Clause and BSD-2-Clause. The SCC code
is used under the BSD-3-Clause license with the author's permission.
The libfdt source code is disjunctively dual licensed
(GPL-2.0+ OR BSD-2-Clause). It is used by this project under the terms of
the BSD-2-Clause license. Any contributions to this code must be made under
the terms of both licenses.
The LLVM compiler-rt source code is disjunctively dual licensed
(NCSA OR MIT). It is used by this project under the terms of the NCSA
license (also known as the University of Illinois/NCSA Open Source License),
which is a permissive license compatible with BSD-3-Clause. Any
contributions to this code must be made under the terms of both licenses.
The zlib source code is licensed under the Zlib license, which is a
permissive license compatible with BSD-3-Clause.
Some STMicroelectronics platform source code is disjunctively dual licensed
(GPL-2.0+ OR BSD-3-Clause). It is used by this project under the terms of the
BSD-3-Clause license. Any contributions to this code must be made under the
terms of both licenses.


This release
This release provides a suitable starting point for productization of secure
world boot and runtime firmware, in either the AArch32 or AArch64 execution
state.
Users are encouraged to do their own security validation, including penetration
testing, on any secure world code derived from TF-A.

Functionality

Initialization of the secure world, for example exception vectors, control
registers and interrupts for the platform.
Library support for CPU specific reset and power down sequences. This
includes support for errata workarounds and the latest Arm DynamIQ CPUs.
Drivers to enable standard initialization of Arm System IP, for example
Generic Interrupt Controller (GIC), Cache Coherent Interconnect (CCI),
Cache Coherent Network (CCN), Network Interconnect (NIC) and TrustZone
Controller (TZC).
A generic SCMI driver to interface with conforming power controllers, for
example the Arm System Control Processor (SCP).
SMC (Secure Monitor Call) handling, conforming to the SMC Calling
Convention using an EL3 runtime services framework.

PSCI library support for CPU, cluster and system power management
use-cases.
This library is pre-integrated with the AArch64 EL3 Runtime Software, and
is also suitable for integration with other AArch32 EL3 Runtime Software,
for example an AArch32 Secure OS.
A minimal AArch32 Secure Payload (SP_MIN) to demonstrate PSCI library
integration with AArch32 EL3 Runtime Software.
Secure Monitor library code such as world switching, EL1 context management
and interrupt routing.
When a Secure-EL1 Payload (SP) is present, for example a Secure OS, the
AArch64 EL3 Runtime Software must be integrated with a dispatcher component
(SPD) to customize the interaction with the SP.
A Test SP/SPD to demonstrate AArch64 Secure Monitor functionality and SP
interaction with PSCI.
SPDs for the OP-TEE Secure OS, NVidia Trusted Little Kernel
and Trusty Secure OS.
A Trusted Board Boot implementation, conforming to all mandatory TBBR
requirements. This includes image authentication, Firmware Update (or
recovery mode), and packaging of the various firmware images into a
Firmware Image Package (FIP).
Pre-integration of TBB with the Arm CryptoCell product, to take advantage of
its hardware Root of Trust and crypto acceleration services.
Reliability, Availability, and Serviceability (RAS) functionality, including
A Secure Partition Manager (SPM) to manage Secure Partitions in
Secure-EL0, which can be used to implement simple management and
security services.
An SDEI dispatcher to route interrupt-based SDEI events.
An Exception Handling Framework (EHF) that allows dispatching of EL3
interrupts to their registered handlers, to facilitate firmware-first
error handling.


A dynamic configuration framework that enables each of the firmware images
to be configured at runtime if required by the platform. It also enables
loading of a hardware configuration (for example, a kernel device tree)
as part of the FIP, to be passed through the firmware stages.
Support for alternative boot flows, for example to support platforms where
the EL3 Runtime Software is loaded using other firmware or a separate
secure system processor, or where a non-TF-A ROM expects BL2 to be loaded
at EL3.
Support for the GCC, LLVM and Arm Compiler 6 toolchains.
Support combining several libraries into a self-called "romlib" image, that
may be shared across images to reduce memory footprint. The romlib image
is stored in ROM but is accessed through a jump-table that may be stored
in read-write memory, allowing for the library code to be patched.

For a full description of functionality and implementation details, please
see the Firmware Design and supporting documentation. The Change Log
provides details of changes made since the last release.

Platforms
Various AArch32 and AArch64 builds of this release has been tested on variants
r0, r1 and r2 of the Juno Arm Development Platform.
Various AArch64 builds of this release have been tested on the following Arm
Fixed Virtual Platforms (FVP) without shifted affinities that do not
support threaded CPU cores (64-bit host machine only):
NOTE: Unless otherwise stated, the model version is Version 11.4 Build 37.

FVP_Base_Aresx4
FVP_Base_AEMv8A-AEMv8A
FVP_Base_AEMv8A-AEMv8A-AEMv8A-AEMv8A-CCN502
FVP_Base_AEMv8A-AEMv8A
FVP_Base_RevC-2xAEMv8A
FVP_Base_Cortex-A32x4
FVP_Base_Cortex-A35x4
FVP_Base_Cortex-A53x4
FVP_Base_Cortex-A55x4+Cortex-A75x4
FVP_Base_Cortex-A55x4
FVP_Base_Cortex-A57x4-A53x4
FVP_Base_Cortex-A57x4
FVP_Base_Cortex-A72x4-A53x4
FVP_Base_Cortex-A72x4
FVP_Base_Cortex-A73x4-A53x4
FVP_Base_Cortex-A73x4
FVP_Base_Cortex-A75x4
FVP_Base_Cortex-A76x4

FVP_CSS_SGI-575 (Version 11.3 build 40)
Foundation_Platform

The latest version of the AArch32 build of TF-A has been tested on the following
Arm FVPs without shifted affinities that do not support threaded CPU cores
(64-bit host machine only).

FVP_Base_AEMv8A-AEMv8A
FVP_Base_Cortex-A32x4

The Foundation FVP can be downloaded free of charge. The Base FVPs can be
licensed from Arm. See the Arm FVP website.
All the above platforms have been tested with Linaro Release 18.04.
This release also contains the following platform support:

Allwinner sun50i_64 and sun50i_h6
Amlogic Meson S905 (GXBB)
ARM SGI-575 and SGM-775
HiKey, HiKey960 and Poplar boards
Marvell Armada 8K
MediaTek MT6795 and MT8173 SoCs
NVidia T132, T186 and T210 SoCs
NXP QorIQ LS1043A, i.MX8QX, i.MX8QM and i.MX7Solo WaRP7
QEMU emulator
Raspberry Pi 3 board
RockChip RK3328, RK3368 and RK3399 SoCs
Socionext UniPhier SoC family and SynQuacer SC2A11 SoCs
STMicroelectronics STM32MP1
Texas Instruments K3 SoCs
Xilinx Zynq UltraScale + MPSoC


Still to come

More platform support.
Position independent executable (PIE) support.
Ongoing support for new architectural features, CPUs and System IP.
Ongoing support for new Arm system architecture specifications.
Ongoing security hardening, optimization and quality improvements.

For a full list of detailed issues in the current code, please see the Change
Log and the GitHub issue tracker.

Getting started
Get the TF-A source code from GitHub.
See the User Guide for instructions on how to install, build and use
the TF-A with the Arm FVPs.
See the Firmware Design for information on how the TF-A works.
See the Porting Guide as well for information about how to use this
software on another Armv7-A or Armv8-A platform.
See the Contributing Guidelines for information on how to contribute to this
project and the Acknowledgments file for a list of contributors to the
project.

IRC channel
Development discussion takes place on the #trusted-firmware-a channel
on the Freenode IRC network. This is not an official support channel.
If you have an issue to raise, please use the GitHub issue tracker.

Feedback and support
Arm welcomes any feedback on TF-A. If you think you have found a security
vulnerability, please report this using the process defined in the TF-A
Security Centre. For all other feedback, please use the
GitHub issue tracker.
Arm licensees may contact Arm directly via their partner managers.

Copyright (c) 2013-2018, Arm Limited and Contributors. All rights reserved.