Explain the internal workings of an RTOS kernel scheduler.

RTOS scheduler manages task execution based on priority and state. Key structures: Task Control Block (TCB) stores context, priority, stack pointer; Ready queue(s) organized by priority; Timer queue for delays. Context switch: Save current task registers to stack, update TCB, select highest-priority ready task, restore new task context. Scheduler invocation: Tick interrupt (time-slicing), Task block (waiting for resource), Task unblock (resource available), and Direct call (yield). Mutex implementation requires priority inheritance to prevent inversion. Considerations: Deterministic scheduling time, minimal interrupt disable time, and efficient queue operations.