Ocera (Open Components for Embedded Real-Time Applications, is an European project, based on Open Source, which provides an integrated execution environment for embedded real-time applications. Ocera combines the use of two kernels, Linux and RTLinux-GPL to provide support for critical tasks and soft real-time applications.
Configuration of Stand-Alone RTLinux
Like Linux or RTLinux, Stand-Alone RTlinux provides a configuration script with "make menuconfig" and "make xconfig". Stand-Alone philosophy is the low memory requirements. We can discard Stand-Alone RTL funcionalities that we won't use.
SA-RTL implements two different memory protection models as opcional funcionalities:
Kernel memory protection. The first one was designed to be extremely efficient and portable, and also to be compatible with the original programming model of RTLinux where all the application threads share all the data.
Context memory protection. The second mechanism is a more complex and powerful implementation that permits to have several protected execution contexts where in each context are executed one or more threads. This second implementation provides protection for several isolated processed where each process runs several threads. It is also possible to run device drivers in one of the protected contexts.
There are two available scheduler implemented Rate Monotic and EDF. If we select EDF we will be able to turn on Stack Resource Protocol in the POSIX configuration submenu.
We can select Posix API that we are going to use.
We can use optional drivers, all drivers available need to turn on the Posix/IO facility in the Posix menu.
