In stark contrast to the user-centric and -friendly world of Android that also spreads into the application developer realm, solid real-time (RT) capabilites are the almost exclusive concern of Linux in the industrial embedded domain.
Frugality dominates the many solutions that bear no resemblance to the colourful Android universe. This is a significant drawback when devices require user interaction. While the learning curve for an Android phone is deemed minimal even for technically unenthusiastic users, comparatively simple tasks (like Stroustrup's infamous use of his own telephone) can become daunting with ill-designed human-machine interfaces.
Analogously, programmers versed in desktop application development face considerable obstacles when turning their attention to embedded Linux work. The combined real-time Android system is supposed to provide remedies for both users and programmers of embedded real-time systems.
In particular our work has applications in machine consolidation: Steadily increasing computational power available in embedded systems, fuelled by a trend towards multi and many-core systems, make it likely that the traditionally independent tasks of RT control and human-machine interface (HMI) provision will be served by a single hardware instance.
This necessitates appropriate basis software architectures, which we present in this paper. Real-time capabilities, which enabled Linux for a much broader embedded audience, were not considered in the Android design. By introducing a real-time capable Android appliance, we add a crucial Linux building block combining the benefits of both realms.
Besides presenting the software architecture, we discuss our efforts in augmenting the Android stack with RT capabilities in a minimally invasive way, provide effort measurements, and present a performance evaluation based on a prototype implemented using a Motorola Xoom tablet featuring our architecture extensions.
To read this external content in full, download the complete paper from the author archives online. http://www.linuxtag.org/2012/fileadmin/www.linuxtag.org/slides/Gernot%20Hillier%20+%20Wolfgang%20Mauerer%20+%20Jan%20Sawallisch%20-%20Android_%20real-time%20for%20the%20rest%20of%20us.p416.pdf