07-12-2012, 06:45 PM
RTOS Design AND Implementation
rtos.ppt (Size: 360.5 KB / Downloads: 101)
Introduction
A variant of OS that operates in constrained environment in which computer memory and processing power is limited. Moreover they often need to provide their services in definite amount of time.
Hard, Soft & Firm RTOS
Example RTOS: VxWorks, pSOS, Nucleus, RTLinux…
Components of RTOS
The most important component of RTOS is its kernel (Monolithic & Microkernel).
BSP or Board Support Package makes an RTOS target-specific (It’s a processor specific code onto (processor) which we like to have our RTOS running).
RTOS KERNEL: Tasks(1)
A task is basic unit of execution in RTOS.
RTOS scheduler needs to be deterministic ~ O(1) or O(n).
Scheduling policies that are available in a RTOS are:
Clock driven
Priority driven (RMS & EDF)