Release of the hypervisor for embedded devices ACRN 1.2, developed under the Linux Foundation

Linux Foundation Organization introduced release of a specialized hypervisor ACRN 1.2, designed for use in embedded technology and Internet of Things (IoT) devices. The hypervisor's code is based on a lightweight hypervisor for embedded devices developed by Intel, and is distributed under the BSD license.

The hypervisor is designed with an eye towards readiness for real-time tasks and suitability for use in mission-critical systems, operating on resource-constrained hardware. The project aims to fill a niche between hypervisors used in cloud systems and data centers, and hypervisors for industrial systems with strict resource partitioning. Examples of ACRN usage include electronic control units, instrument panels, and automotive information systems, but the hypervisor is also well-suited for consumer IoT devices and other embedded applications.

ACRN provides minimal overhead and consists of only 25,000 lines of code (for comparison, hypervisors used in cloud systems have about 150,000 lines of code). At the same time, ACRN guarantees low latency and adequate responsiveness when interacting with hardware. It supports virtualization of CPU resources, input/output, networking subsystems, and graphics and audio operations. A set of input/output mediators is provided for shared access to resources common to all VMs.

ACRN is a type-1 hypervisor (runs directly on the hardware) that allows multiple guest systems to run simultaneously, in which various Linux distributions, RTOS, Android, and other operating systems can be launched. The project consists of two main components: the hypervisor and its associated device model with a rich set of input/output mediators that facilitate shared access to devices among guest systems. The hypervisor is managed from a service OS that acts as the host system and contains components for translating calls from other guest systems to hardware.

Key changes in ACRN 1.2:

• Support for firmware Tianocore/OVMF as a virtual bootloader for the service OS (host system) capable of running Clearlinux, VxWorks, and Windows. Verified boot mode (Secure boot) is supported;
• Container support Kata;
• For Windows guest systems (WaaG), a mediator has been added for accessing the USB host controller (xHCI);
• Always Running Timer virtualization added (ART).

Source: opennet.ru