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2017-06-27 - 17:48

Dates and Events:

Breaking News:

2016-11-12 12:00

Raspberry Pi and real-time Linux

Let's have a look at the OSADL QA Farm data

2016-09-17 12:00

Preemption latency of real-time Linux systems

How to measure it – and how to fix it, if it's too high?

2014-11-18 00:00

Linux real-time: New stable release available -

but next one depends on more support from industrial users

OSADL Projects

OSADL Project: Migration & Portability Projects

In addition to the creation and development of new software, OSADL is similarly involved in helping machine and automation companies to migrate existing projects to Linux and to take care of software portability. This aspect is particularly important for such companies since

  • a large part of the software is developed in-house and represents a considerable investment that must be protected
  • the product life cycle and, thus, the service period may be up to 10 times longer than, for example, in office automation. In consequence, the same software must possibly be ported to several generations of computer hardware.

Currently, three projects deal with migration and portability issues: Xenomai/SOLO, RTDM-native and RBF file system.

Xenomai/SOLO: Migration from VxWorks® to Linux

Xenomai 2.x is one of the Linux real-time extensions developed to provide real-time capabilities to Linux. It is available since several years and was employed to successfully realize a large number of industrial projects. Xenomai 2.x uses the so-called "co-kernel" approach, i.e. real-time applications run on a separate RTOS kernel (aka the Xenomai "nucleus") that co-operates with the Linux kernel. This co-operation is handled via an interrupt pipeline layer ("Adeos"). As an important advantage, Xenomai 2.x provides a set of APIs (so-called "skins") that emulate traditional RTOSes such as VxWorks and pSOS and implement other APIs such as POSIX. Using these skins, a number of projects have been migrated smoothly from one of the supported traditional RTOSes to Xenomai/Linux. In order to use a similar approach to migrate traditional RTOS projects to native Linux as well, Xenomai 3.x was inaugurated, but this project still has a long way to go, since a number of building blocks and interfaces have to be adapted, if the same emulator code is going to be used for both the co-kernel and native Linux versions of Xenomai.

As an intermediate step towards Xenomai 3.x, the Xenomai/SOLO project was created. It is a clean-room re-implementation of the building blocks that connect an emulator with the underlaying RTOS with special respect to the requirements and semantics of the native Linux kernel. The VxWorks® emulator was the first one built over the Xenomai/SOLO project. It provides the VxWorks core API that can be used to port existing VxWorks® applications to native Linux.

Xenomai/SOLO was developed and contributed by Philippe Gerum co-sponsored by OSADL founding member Denx Software Engineering and OSADL. A HOWTO will be available soon, download instructions are given here.

RTDM-native: Port RTDM-drivers to native Linux

The RTDM-native framework allows to use existing RTDM-conforming drivers under native Linux. This project war developed by Wolfgang Grandegger in a joint venture between OSADL founding member Denx Software Engineering and OSADL. A HOWTO is available here, download instructions are given here. Jan Kiszka's paper "The Real-Time Driver Model and First Applications" that was presented at the Seventh Real-Time Linux Workshop 2005 is available here.

RBF File System: Use OS-9® formatted media under Linux

This project aims to provide the RBF file system, the standard OS-9®file system, for Linux. It makes it possible to read and write floppy disks, hard disks, RAM disks etc. that have been formatted with the RBF file system. The software was developed initially by Andrew Cannon for Linux 2.4 and ported to Linux 2.6 by Carsten Emde who is currently maintaining it. A detailed description is available in this HOWTO, download instructions are given here.