At the high end of the Atmel product spectrum resides SAMA5 based on an ARM Cortex-A5 core. With an MMU supporting Linux or Android, plus on-the-fly memory encryption and ARM TrustZone in some variants, the SAMA5 family is drawing interest from IoT app developers. We’ll look at three examples, all illustrating how important seamless trust is becoming for the IoT.
The struggle to achieve low power and small size for IoT edge devices is ongoing, but in many cases going too low on the processor spectrum leaves security open to compromise. Selecting a slightly more powerful core can enable a considerably more robust implementation, adding the potential for end-to-end security spanning all three IoT tiers – edge, gateway, and infrastructure.
For example, startup Sequitur Labs has ported their CoreTEE (trusted execution environment) to the Atmel SAMA5D4 and SAMA5D2. CoreTEE makes heavy use of TrustZone to provide gateway functions such as secure boot, firewalling, secure peripheral drivers, static and dynamic loading of trusted apps, and a framework for crypto key management. Sequitur is not a run-of-the-mill startup, instead composed of industry vets combining experience from places such as Boeing Phantom Works, Nortel, Qualcomm, and T-Mobile.
TrustZone support is a big deal, and it is one reason ARM-based IoT infrastructure chips make sense. ARM said at TechCon 2015 they are in process of adding TrustZone to the Cortex-M profile (ARMv8-M), but they haven’t announced a product yet – Sequitur currently has a separate slimmed-down product, CoreLockr, for edge devices. The CoreTEE platform was demonstrated at Embedded World 2016, with a trusted gateway based on the Atmel SAMA5D2 talking to an edge node (on an Atmel SAMD21) and a Samsung Galaxy Note 4 coordinating a simple building access application with end-to-end trust.
Atmel also had the second generation of their Smart Badge Demonstrator at Embedded World 2016. It amounts to a wearable reference platform, with the Atmel SAMA5D3 running Android and six applications from Adeneo Embedded. An Atmel MXT112 provides the touch screen capability, an Atmel WILC3000 handles Wi-Fi and Bluetooth, and an Atmel SAM G54 handles sensor hub functions including a MEMS accelerometer. Connectivity between the badge and a smartphone looks solid, although with the SAMA5D3 the TrustZone component is missing – easily addressed by moving to another variant.
Another Embedded World 2016 demonstration went directly after the IoT gateway in a small platform designed for OpenWRT. The DAB-EMBEDDED Smart Router puts an Atmel SAMA5D36 next to an Altera MAX 10 FPGA, allowing full customization of sensor interfaces. It’s an interesting approach for a compact IoT gateway reference design. One thing I hear a lot is many IoT projects aren’t ready to commit to fully customized hardware (an SoC design start) and want to pilot a project quickly without a big investment. DAB-EMBEDDED is also keeping other options open – I saw an email chain saying they are looking at Windows 10 IoT Core for this platform as soon as Microsoft turns the portable BSP loose.
From this we see the SAMA5 is where much of the IoT action in the Atmel ecosystem is happening. The combination of processor performance plus an LCD controller, USB and Ethernet, optional CAN, and the security features – all at a low power point – make it a solid choice for many IoT and wearable use cases. Incorporation of ARM TrustZone technology for IoT apps is only going to accelerate, likely making it a checklist item for processor selection very soon. Secure boot and memory encryption are also factoring into the trust equation more.
I really hope the Apple-FBI dustup over encryption does not stall the IoT conversation on security and trust. I think designers who skip end-to-end protection across all three tiers are going to regret cutting that corner. At the gateway tier and in some higher-performance edge devices, with processors like the Atmel SAMA5 and software solutions like Sequitur’s CoreTEE, there is no excuse for not using a more capable processor right now.
More reading on these ideas:Atmel SAMA5 product info
Sequitur Labs’ Enhances IoT and Embedded Security with CoreTEE
Atmel Smart Badge Demonstrator video at Embedded World 2016
DAB-EMBEDDED OpenWRT Smart Router