Among solutions to allow sub-millisecond determinism for real-time Linux applications, the co-kernel approach is found in many products and is probably to most widely known — and used — technique. In the past few years, this approach evolved, at least in the RTAI project, towards a better integration of the co-kernel deterministic services to Linux:

• the co-kernel interfaces were brought to… (more…)

Embedding Linux in a carrier-grade application, like a Microwave Point-to-Point Radio Link, has many interesting concerns. These concerns range from technical issues, cost calculation issues to even political or licensing issues. However, when compared to an existing proprietry-only product which binds a company to long development cycles, it has many relatively obvious advantages. (more…)

This paper presents the experimental study of the performance of Real-Time Linux based on the x86 architecture. Holding the hardware constant and using different measurement methodologies, we measured a list of performance (ten kinds of test), including the overheads incurred during operating systems context switching test, conditional variable test, rt-fifo read/write test, mbuff read/write test, etc. (more…)

This paper describes an implementation of the Linux kernel and applications on a unique commercial-off-the-shelf component based space borne computer system. This system, called the parallel processing unit has been developed for the X-Sat micro-satellite mission. Interfaces using the kernel device driver model are utilised to allow seamless application interaction with the system hub. (more…)

Scheduling theory has shown an impressive evolution due to the intensive research done in this area. As a result, a lot of scheduling algorithms has been proposed to support a large amount of applications. RTLinux uses a fixed-priority scheduler and although fixed-priority scheduling is suited for a large number of real-time applications, it has some drawbacks. (more…)

This work-in-progress report describes a distributed hybrid architecture that imparts autonomous intelligence capabilities of “perception-decision-action” to an ALV (Autonomous Landing Vehicle) control unit. The system is shown to degenerate to a remote thread execution mechanism of a real-time operating Linux system where the kernel instantiation is control strategy dependent. (more…)

There has been increasing interest in the real-time community for Quality of Service (QoS) based systems, such as multimedia and telecommunication systems. In this paper, we deal with scheduling components integrating new QoS functionalities under Linux/RTAI (Real-Time Application Interface) [Rta04]. (more…)

There is a strong tendency towards using modern Personal Computers for various tasks they are not designed for. This also includes audio and video processing. Audio and Video data is real-time data. It needs to be dispatched within predefined and fixed time windows to avoid perceivable lags and dropouts. (more…)

A deterministic response time is the most important and necessary feature in Hard Real-Time Systems. This is the main reason why some years ago it was unthinkable to implement Hard Real-Time Systems with the Java language, an object-oriented, interpreted language, mainly because Java uses garbage collection to implicitly deallocate dynamic memory; This is widely known as“the garbage collection problem''… (more…)

RTLinux does not support direct access to any kind of permanent massive storage system, and in particular IDE hard disks. When a RTLinux thread has to store data on the hard disk, it has to use the Linux services. The usual way of doing the transfer is by means of RTFifos: a rtl-task sends the data to Linux through an RTfifo, and then, a Linux process writes this data on the hard disk. (more…)

This paper describes a fixed-point arithmetic implementation of linear time-invariant digital filters in the C programming language, targeted for the use in real-time applications. FIR and IIR filters are presented in different configurations and representations, such as direct and transposed forms, as well as wave, state-space and normal forms. (more…)

Talk abstract: IBM researchers are successfully running Linux and X11 on a unique wrist watch, demonstrating the viability of Linux across all platforms — from large supercomputer clusters to the smallest intelligent devices. In this keynote presentation, Alex Morrow discussed IBM's far-reaching Linux activities and talked in detail about (and demonstrated on videotape) the incredible IBM Linux… (more…)

Scilab/Scicos is an open source project developed at the INRIA (Insitut National de Recherce on Informatique et on Automatique) in France which can be used to successfully replace other commercial and expensive software in solving mathematical and control problems. This software integrates a code generator for Scicos which has been modified and completed to automatically generate a code for the RTAI-Lab… (more…)

Talk abstract: Debian GNU/Linux is a natural choice as the basis for embedded Linux, due to its open development process, reliability and security, powerful package manager, and wide range of supported architectures. The Embedded Debian Project intends to create a Debian-based Embedded Linux that is scalable, supports a wide range of platforms, integrates embedded Linux related software from a… (more…)

Real Time applications involve time-critical tasks, which are to be run in a high precision scheduling environment always meeting the timing constraints. Applications which run on RT Linux uses a hard real-time kernel for tasks which needs real-time processing and the Linux OS for other non real-time tasks. (more…)