1. Article purpose
The purpose of this article is to:
- briefly introduce the TZC peripheral and its main features
- indicate the level of security supported by this hardware block
- explain how it can be allocated to the three runtime contexts and linked to the corresponding software components
- explain, when necessary, how to configure the TZC peripheral.
2. Peripheral overview
The TZC peripheral is used to filter read/write accesses to the DDR controller according to TrustZone access rights, and according to Non-Secure master Address ID (NSAID) on up to 9 programmable regions.
2.1. Features
Refer to the STM32MP15 reference manuals for the complete list of features, and to the software components, introduced below, to see which features are implemented.
2.2. Security support
The TZC is a secure peripheral.
3. Peripheral usage and associated software
3.1. Boot time
The TZC is configured at boot time to setup DDR accesses.
3.2. Runtime
3.2.1. Overview
The TZC is a system peripheral and is controlled by the Arm® Cortex®-A7 secure.
3.2.2. Software frameworks
Internal peripherals software table template
| Security | TZC | OP-TEE TZC driver | | | |- |}
3.2.3. Peripheral configuration
The configuration is applied by the firmware running in the secure context.
This configuration is done in TF-A or in OP-TEE.
3.2.4. Peripheral assignment
Internal peripherals assignment table template
| rowspan="1" | Security | rowspan="1" | TZC | TZC | ✓ | | | |-
|}
4. How to go further
The TZC is an Arm® peripheral: TZC-400 TrustZone Address Space Controller[1]
5. References