Flexible Low-Level System Programming in Apertos Operating System
and Mario Tokoro
ACM OOPSLA'94 Workshop on Flexibility in System Software Position Paper
This position paper states our new approach of implementing
low-level OS components, especially device drivers.
We introduce the notion of concurrent objects into low-level
A device driver for every hardware device is implemented as
independent concurrent objects.
A device driver object has a single thread of control, so that
mutual exclusion operations such as spl and semaphores are not
Mechanisms of synchronization, object scheduling, and interrupt
mask handling are clearly separated from actual device control
programs, and these are implemented by the system for device
By these methods, low-level OS components can be made flexible and
executed safely, with practical performance.