Microsoft adds another non-Windows OS as it pushes Azure towards IoT

Microsoft has acquired 23-year old Express Logic, which provides real time operating systems (RTOS) for IoT and edge devices running on microcontrollers (MCUs). This is another move that sees the firm belatedly accepting that the new world of IoT, edge and 5G means it has to abandon the idea that Windows is suited to everything.

Under previous CEO Steve Ballmer, Microsoft wasted a lot of effort squeezing Windows into applications for which it was ill-suited, particularly in the embedded and low power markets. Windows Mobile, Embedded, Auto and others were always outshone by Linux-based options, while the single-OS strategy always kept the software giant out of the MCU world.

That was of little account when RTOS ran on specialized, relatively niche products, but with the rise of the IoT, these may become far more mainstream operating systems.

Express Logic’s ThreadX RTOS has more than 6.2bn deployments, making it one of the most popular such OSs in the world, according to a blog post by Sam George, Microsoft’s director of Azure IoT.

The OS is used in “highly constrained devices”, such as light bulbs, temperature gauges, air conditioners, medical devices and network appliances, which are “battery powered and with less than 64KB of flash memory”. Overall, more than 9bn such devices are deployed every year, according to George.

As the name implies, RTOS systems require real time data processing, and so they are designed to provide guaranteed process delivery time – that is, a guarantee for how long it takes to act on an input and deliver the output. The design prioritizes this speed, rather than the compute horsepower and throughput. Because of the architecture’s design, it is used in systems that have very little or even no tolerance for execution failures.

The acquisition – for an undisclosed amount – is the second recent move towards having more specialized OS platforms to extend Microsoft’s reach in mobile, IoT and edge devices, after the launch of Azure Sphere for edge products. These days, the primary aim is not to drive per-device OS shipments as in the Windows heyday – current CEO Satya Nadella is a cloud man, and has turned Microsoft into a cloud giant with a business centered around Azure. So the sacrifice of ‘Windows everywhere’ is a small price to pay to support the most efficient end points that will be encouraged to connect to Azure cloud and edge services.

This is at the other end of the scale that Microsoft is currently most busy in, that is the cloud computing sector. However, the cloud is essentially the great translating layer for the IoT, and so any device that generates data packets and can be connected to the internet in some fashion can feasibly talk to any connected system in the world. To this end, any improvement in how an RTOS-powered device goes about doing this could be beneficial to Microsoft’s Azure strategy.

“With this acquisition, we will unlock access to billions of new connected end points, grow the number of devices that can seamlessly connect to Azure and enable new intelligent capabilities,” said George. “Express Logic’s ThreadX RTOS joins Microsoft’s growing support for IoT devices and is complementary with Azure Sphere, our premier security offering in the microcontroller space.”

Azure Sphere takes a three-pronged approach, starting at the chip itself, with a new family of microcontrollers (MCUs). The chips are intended to provide hardware-based security, through secure enclaves for handling encryption keys, as well as the real-time and application processor requirements. It seems like these are meant to be standalone chips, to power devices, not add-ons or augmentations.

The next step up is the Azure Sphere OS, which is actually based on Linux – quite a departure for Microsoft. The company says that Azure Sphere OS houses a custom Linux kernel, as well as security innovations that were ‘pioneered in Windows,’ to provide a highly secure software environment to run trustworthy IoT devices and experiences.

The move to being more Linux friendly came into being after Nadella took charge. There has been a subtle rebranding of the cloud platform, shifting it from Windows Azure to Microsoft Azure, and parts of Windows itself have been opened up to Linux.

The final component is the Azure Sphere Security Service, the cloud-based component that will be brokering the device-to-device and device-to-cloud relationships. It will be using all the data collected from Azure Sphere deployments to spot emerging security threats.

“Effective immediately, our ThreadX RTOS and supporting software technology, as well as our talented engineering staff, join Microsoft,” Express Logic CEO William Lamie said in a statement. “The significant growth of the IoT provides exciting new opportunities for our customers and the embedded market overall. Now as part of Microsoft, we believe our customers will be even better positioned to unlock exciting new capabilities of the IoT.”

ThreadX is one of the more prominent RTOS flavors in a fragmented market. Wind River’s VxWorks is a well-known option – Wind River was recently ditched by Intel and sold off to a private equity firm.  Other RTOSs include BlackBerry’s QNX, Zephyr, FreeRTOS (which is now under Amazon’s stewardship) and Arm’s Mbed OS. New designs appear quite regularly, including Apache’s MyNewt, Riot OS and Contiki.