ReaGOS - Application Specific Real-Time Kernel

ReaGOS is an a preemptive single-stack kernel. Its main advantages are fast scheduling and small footprint. The kernel is generated automatically from a high level graphical description of the application, so, much of run-time setup and lookup can be avoided.

Operating principles

• preemptive scheduling with static priorities
• message based inter -task communication
• interrupts are handled directly by device specific interrupt handlers
• all tasks share the same stack
• event driven
• scheduling of lower priority tasks can be interrupted for a higher priority task

Benefits

• allows fast response times for some urgent events while heavy computation is under execution
• supports data-flow based concurrent software architecture
• support multiple waiting: any event concerning the task activates the task as soon as possible
• support accurate timing without drift; it is easy to implement precisely timed sequences
• supports easy implementation of inter-task data flows with user definable data types and static buffering
• is based on static data structures for deterministic behaviour
• supports fast and small final system code including the application and the kernel
• supports straightforward and effective interrupt processing
• includes no excess operating system functions
• is portable at the source code level
• is configured and interfaced automatically to application

Publication

• Okkonen Ari, et al., ReaGOS - An Application Specific R/T-OS, 5th Euromicro Workshop on Real-Time Systems, Oulu, Finland, June 22-24, 1993 [PDF]

Performance

• Speed measurement of a ping-pong system

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