This patch modifies the delay timer driver to switch to the ARM secure physical timer instead of using Tegra's on-chip uS timer. The secure timer is not accessible to the NS world and so eliminates an important attack vector, where the Tegra timer source gets switched off from the NS world leading to a DoS attack for the trusted world. This timer is shared with the S-EL1 layer for now, but later patches will mark it as exclusive to the EL3 exception mode. Change-Id: I2c00f8cb4c48b25578971c626c314603906ad7cc Signed-off-by: Varun Wadekar <vwadekar@nvidia.com> |
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bl2u | ||
bl31 | ||
bl32 | ||
common | ||
docs | ||
drivers | ||
fdts | ||
include | ||
lib | ||
make_helpers | ||
plat | ||
services | ||
tools | ||
.checkpatch.conf | ||
.editorconfig | ||
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Makefile | ||
dco.txt | ||
license.rst | ||
readme.rst |
readme.rst
Trusted Firmware-A
Trusted Firmware-A (TF-A) is a reference implementation of secure world software for Arm A-Profile architectures (Armv8-A and Armv7-A), including an Exception Level 3 (EL3) Secure Monitor. It provides a suitable starting point for productization of secure world boot and runtime firmware, in either the AArch32 or AArch64 execution states.
TF-A implements Arm interface standards, including:
- Power State Coordination Interface (PSCI)
- Trusted Board Boot Requirements CLIENT (TBBR-CLIENT)
- SMC Calling Convention
- System Control and Management Interface (SCMI)
- Software Delegated Exception Interface (SDEI)
The code is designed to be portable and reusable across hardware platforms and software models that are based on the Armv8-A and Armv7-A architectures.
In collaboration with interested parties, we will continue to enhance TF-A with reference implementations of Arm standards to benefit developers working with Armv7-A and Armv8-A TrustZone technology.
Users are encouraged to do their own security validation, including penetration testing, on any secure world code derived from TF-A.
More Info and Documentation
To find out more about Trusted Firmware-A, please view the full documentation that is available through trustedfirmware.org.
Copyright (c) 2013-2019, Arm Limited and Contributors. All rights reserved.