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RTOS and its architecture

Short answer

An RTOS guarantees tasks meet strict deadlines. Its architecture layers: application tasks, RTOS API, kernel (scheduler, task management, inter-task communication, timers, memory, interrupt handling), device drivers/BSP, and hardware. The kernel core provides deterministic scheduling and synchronization services.

Briefly explain real time operating system. With neat diagram explain its architecture.

A Real-Time Operating System (RTOS) is an operating system that guarantees to complete tasks and respond to events within strict, predictable time limits. It manages tasks, time and resources so that deadlines are met (hard or soft real-time). Examples: VxWorks, uC/OS-II, FreeRTOS, QNX.

Architecture

 +-----------------------------------------------+
 |        Application tasks (Task1 ... TaskN)    |
 +-----------------------------------------------+
 |                RTOS API / system calls        |
 +-----------------------------------------------+
 |  Kernel:                                      |
 |   Scheduler | Task mgmt | Inter-task comm.    |
 |   Timer/clock mgmt | Memory mgmt | I/O mgmt   |
 |   Interrupt handling | Synchronisation        |
 +-----------------------------------------------+
 |  Device drivers / Board support package (BSP) |
 +-----------------------------------------------+
 |       Hardware: processor, memory, I/O        |
 +-----------------------------------------------+
  • Kernel: the core containing the scheduler (priority pre-emptive), task management (create, delete, suspend, resume), inter-task communication and synchronisation (semaphore, mutex, queue, event, mailbox), timers and memory management.
  • Interrupt handling: low latency, ISR to task signalling.
  • Device drivers / BSP: hardware-dependent software.
  • Application layer: user tasks run on top, using the API.

✓ Answer checked by Claude Opus 5.5 (high effort)

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