SoylentNews is people
SoylentNews
Although a wide range of potential applications exists for the ARMV8-M processors, developers working on secure real-time applications will certainly see the largest benefit. So far, the ARMV8-M architecture can be found in M23 and M33 Cortex-M and M35P processors. Let’s take a look at the new features included in ARMV8-M and how these processors differ from previous generation ARMV7-M parts.
[...] The ARMV8-M feature that really sets the M23, M33, and M35P apart is their support for ARM TrustZone. TrustZone is a security extension that provides hardware isolation within the microcontroller so that developers can create secure and unsecure regions. These regions can be locations in RAM, Flash, or even interrupts and peripherals. The separation between secure and unsecure regions creates isolation within the microcontroller, allowing developers to protect mission-critical code and data.
The isolation creates two new modes that the processor can be running in: secure and unsecure. When in secure mode, the executing code can access all memory within both the secure and unsecure zones. However, if the processor is executing in the unsecure zone, only the unsecure regions can be seen. The secure regions are hidden and cannot be executed from the unsecure state without special code being added, which creates a gateway to access a secure call. This makes it possible to use secure functions while hiding what is happening behind the scenes.
There are several other new features that developers will find interesting besides the TrustZone extension. These include:
- Simpler MPU setup
- Flexible breakpoint configuration
- Improved trace support
- Instruction set enhancements
- Dynamic reprioritization of interrupts
(Score: 4, Interesting) by ataradov on Saturday August 11 2018, @01:32AM (1 child)
You are wrong. ARM8-M is a microcontroller profile. TrustZone here is purely a way to separate your own trusted and untrusted code. For example you can run some control loops or even some secret things in the trusted part, and the UI in the untrusted part.
But ultimately the device has to be programmed with an image, and this image has to be accessible at the programming time.
The manufacturer can lock everyone else out, if they want to, of course. But the plain chip inherently does not contain any "trusted" code.
(Score: 2, Interesting) by ataradov on Saturday August 11 2018, @01:37AM
Although that depends on what you understand by "manufacturer". It will not be the manufacturer of the chip. But a manufacturer of some equipment wants to buy chips and program them to be partially locked with a trusted code, they would be able to do so.
But this does not make things any worse, since in a word of microcontrollers you already can lock the entire device.