ISOS is an acronym that stands for "Isos is a Simple Operating System". It has been developed mainly during December 2002 to February 2003 to provide a simple multi-threaded environment for the Evaluator-7T evaluation board from ARM Ltd.
It is based on JaysOS a "Toy OS" developed for the Gameboy Advance which also uses a 7TDMI processor. ISOS is in fact a simplified version of JaysOS that does mainly multi-threading without handling graphical interface (the Evaluator-7T doesn't have a screen!).
The system has then been modified/enhanced with the use of more dynamic memory allocation and of course some custom "drivers" for the Evaluator-7T's hardware (DIP switches, LEDs, 7-segment display, user serial interface, etc.). It does however not provide direct means to use the Ethernet controller and the HDLC controllers.
This project has been started and is used to provide an adequate environment for programming a robot directly with the Evaluator-7T board for a robotic competition. The board being embedded into the robot using its power supply, sensors and motors. More information about the robot and the competition.
ISOS has the following main characteristics:
- Preemptive multi-threading (up to 31 threads).
- Message queues (asynchronous communication between threads).
- Condition locks & semaphores.
- Alarms (possibility to program the execution of a function at a given time).
- Serial interface driver.
- Means to use the board's hardware (Switches, LEDs, etc.).
- One 32-bit timer available to the user.
- Includes a simple "shell" application that can display system information through the user serial interface.
© 2003 Wilhem Meignan.