Armv8-M architecture extends TrustZone technology to Cortex-M based systems, enabling robust levels of protection at all cost points. TrustZone for Armv8-M has the same high-level features as TrustZone on applications processors, with the key benefit that context switching between secure and non-secure worlds is done in hardware for faster transitions and greater power efficiency. There is no need for any secure monitor software.
TrustZone for Armv8-M is an ideal technology to use with the Platform Security Architecture (PSA) as it provides hardware isolation between the normal code and the trusted code base. It also provides a mechanism to provide trusted hardware that might include hardware-backed secure storage, Random Number Generators (RNG) and a source of secure time.
Embedded software developers enhance their productivity by developing TrustZone systems using C language, while maintain the existing programmer’s model for the Non-secure side. Debug operations are also supported with sensitivity to access the secure versus the non-secure states.
TrustZone for Cortex-M is used to protect firmware, peripheral and I/O, as well as to provide isolation for secure boot, trusted update and root of trust implementations without compromising the deterministic real-time response expected for embedded solutions.
A System-Wide Approach to Software Security
Arm TrustZone technology provides system-wide hardware isolation for trusted software. Used on billions of application processors to protect high-value code and data, it creates an isolated secure world to provide confidentiality and integrity to the system, protecting almost any asset from specific attacks.
The concept of hardware-separated secure and non-secure worlds is at the heart of the TrustZone approach. The Non-secure software is blocked from accessing Secure resources directly, and this isolation extends beyond the processor to encompass memory, software, bus transactions, interrupts and peripherals within a system-on-chip (SoC). Both Cortex-A and Cortex-M processor families offer the same security concepts, but with a different form of implementation.
TrustZone technology provides a foundation for system-wide security and the creation of a trusted platform. Any part of the system can be designed to be part of the Secure world, including debug, peripherals, interrupts and memory. By creating a security subsystem, assets can be protected from software attacks and common hardware attacks.
PSA provides a common security foundation for the whole IoT ecosystem and includes many elements, including architecture specifications and threat models. An important part of PSA is open source firmware, called Trusted Firmware-M. This enables SoC developers and OEMs to benefit from a reference implementation of low-level secure world software. This software is available as open source on GitHub.
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The Cortex-M33 is optimized for cost and power-sensitive microcontroller and mixed-signal applications, especially those that require efficient security or digital signal control.
Cortex-M23 is the smallest and lowest-power microcontroller with TrustZone security, making it the ideal processor for applications where software isolation and software security are required.
Cortex-M35P is the first Armv8-M processor with tamper-resistance built in to bring physical security within reach of any IoT product.
Everything you need to know to make the right decision for your project. Includes technical documentation, industry insights, and where to go for expert advice.