IoT Operating Systems ISE Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   An IoT device runs an RTOS and handles sensitive data. The developer wants to prevent a compromised task from reading the memory of other tasks. Which mechanism should the RTOS provide?

   • AEncryption of all data in RAM
   • BA global variable that stores the current task ID
   • CMemory protection unit (MPU) that enforces per-task memory access permissions
   • DDisabling interrupts during task switches
   Reveal Solution Discussion Select an answer first
2. 2application · medium

   An RTOS has two tasks: Task A (high priority) and Task B (low priority). Task A is blocked waiting for a semaphore held by Task B. A medium-priority Task C becomes ready. What is the likely outcome if the RTOS does not implement priority inheritance?

   • ATask B inherits Task A's priority and runs before Task C
   • BThe RTOS deadlocks because Task C holds a resource needed by Task A
   • CTask C runs, delaying Task B and thus delaying Task A, causing priority inversion
   • DTask A immediately preempts Task C and runs
   Reveal Solution Discussion Select an answer first
4. 3expert · hard

   An IoT device uses an RTOS with a memory protection unit (MPU). A developer wants to add a new third-party library that requires dynamic memory allocation. The device has 64 KB of RAM and the system previously used only static allocation. What is the best approach to maintain memory safety while accommodating the library?

   • AAllocate a fixed-size memory pool for the library and configure the MPU to restrict the library's access to that pool
   • BIncrease the stack size of the calling task to accommodate the library's dynamic allocations
   • CAllow the library to use the system heap without restrictions
   • DDisable the MPU to simplify memory management
   Reveal Solution Discussion Select an answer first
5. 4foundation · easy

   What is the primary purpose of a scheduler in a real-time operating system?

   • ATo allocate memory to tasks
   • BTo manage power consumption of the CPU
   • CTo handle hardware interrupts
   • DTo determine which task runs at any given time
   Reveal Solution Discussion Select an answer first
6. 5expert · hard

   A company is selecting an OS for a new line of smart meters. The meters must support MQTT over Wi-Fi, have a battery life of 10 years, and be field-updatable. The team is considering a lightweight RTOS with a Wi-Fi stack and a full Linux distribution. Which factor is most critical in making the decision?

   • AThe RTOS can provide deterministic scheduling and low-power sleep modes, which are essential for battery life and real-time meter reading
   • BThe RTOS has a smaller memory footprint, which is the only consideration
   • CLinux provides a richer set of networking protocols and easier development
   • DLinux supports secure boot and encryption out of the box
   Reveal Solution Discussion Select an answer first