Open source real-time operating systems (RTOS) is a major trend in the software industry, particularly for embedded systems where the ability to understand code at the very lowest levels is often critical. Users can save days of time researching and isolating a problem with source code access.
 
In many cases, in the past vendors have tried to hide their source code from users in the embedded space, or forced them to pay exhorbitant sums for source code access. This was and still is the typical model of many vendors today. Waiting several days to get someone to debug an application that was reduced to a few lines of code over the previous week to demonstrate a defect is not a rewarding experience. Neither is paying  as much as $100 000 for source code access.  Fortunately, most operating systems offer source code now.
 
Open source and open standards should not be confused.  Open standards support is as important as community based, open source development and enhancement.  Open standards for operating systems include Linux APIs and POSIX.  Although POSIX is the standard strictly speaking, most users don't make the distinction.  They are in fact compatible and all open source operating systems should be POSIX and LInux compatible today.
 
Open source models for many embedded system components are common and beginning to dominate the market for these reasons. At RoweBots, we provide two open source RTOS solutions which target different levels of performance and capabilities for DSP systems. Both are built around POSIX and other open standards and languages to ensure that applications have maximum portability.
 
At the very low end of the performance scale for DSP systems, applications use digital signal controllers (DSCs) or digital signal processors (DSPs). These are inexpensive yet offer good DSP performance and can easily connect into small networks to deliver a bigger performance envelope. A DSP RTOS is a good solution for getting everything to work together, The open source RTOS for DSP that RoweBots offers to solve these problems is called DSPnano.
 
Some embedded DSP systems require many processors – HD H.264 encoding being a case in point. For these systems many processors using shared memory are required. Often multicore processors with fast interconnect networks are used. In other cases, users are building large arrays of processors with more distributed topologies. In these cases a larger and more flexible RTOS is required – with exactly the same POSIX interfaces – to provide a transparent multicore and distributed core runtime. The open source RTOS which provides this is the Unison DSP RTOS.
 
One of the major advantages of an open source RTOS is its vendor independence. Because users have access to source code, both RTOS solutions have been engineered to work with open standards, and the open source RTOSs have been designed to be portable; users can port to any hardware that they want.
 
The benefits of not being locked in are enormous when negotiating contracts for volume chip production. If you use a chip vendor's RTOS you are locked in without negotating position. If you use a non open source RTOS you are limited to those chips that are currently supported and may not be able to move. If you use an open source RTOS, it gives you the best of all worlds: portability and chip vendor independence. This open source RTOS feature can save you millions of dollars in volume production.