Real-Time Operating Systems Quiz 1

What is the primary role of the kernel in a real-time operating system (RTOS)?

• Manage low-level I/O operations directly

• Handle interrupt requests only

• Manage tasks, scheduling, and resource allocation

• Replace hardware-level timers

What is CMSIS-Core designed to provide?

• High-level task management

• A hardware abstraction layer for Cortex-M microcontrollers

• Peripheral drivers for STM32 microcontrollers

• Power management for low-power systems

Which of the following accurately describes context switching in an RTOS?

• Swapping hardware interrupts between cores

• Saving and restoring the state of a task to switch to another task

• Resetting all tasks when a new task arrives

• Allocating additional stack space for higher-priority tasks

In Rate-Monotonic Scheduling (RMS), why are tasks with shorter periods assigned higher priority?

• To ensure deadlines of low-priority tasks are always missed

• Because they have longer deadlines

• To meet frequent execution requirements for time-critical tasks

• To improve CPU power consumption

How do interrupts and preemptive scheduling differ?

• Interrupts pause only kernel tasks, while preemption affects all tasks

• Preemption is used for real-time deadlines, while interrupts are for event handling

• Interrupts are triggered by software events, preemption by hardware

• Interrupts are synchronous, preemption is asynchronous

What is the main advantage of using fixed-priority scheduling in embedded systems?

• It guarantees 100% CPU utilization

• It avoids task starvation by balancing priorities dynamically

• It provides predictable timing for real-time applications

• It ensures tasks are executed in the order they are created

Which timer function is typically implemented by the SysTick Timer in Cortex-M microcontrollers?

• Generating PWM output

• Time-stamping UART data

• Periodic scheduler interrupts for task management

• Resetting stack pointers

What is the purpose of Auto-Reload Register (ARR) in PWM generation?

• Control the duty cycle of the output waveform

• Set the maximum count value for the timer period

• Enable interrupts for task switching

• Store task context data during preemption

In CMSIS-RTOS, which mechanism is used to block a task for a specific time delay?

• osContextSwitch()

• osSignalSet()

• osDelay()

• Delay()

How does a task in a real-time system return to an ready state?

• By calling a yield function

• When another higher-priority task preempts it

• When its time slice expires and no other task is ready

• By disabling its priority manually