What is ZenOS RTOS?
ZenOS RTOS is a compact C++11 real-time operating system for ARM Cortex-M embedded systems, including STM32-oriented projects. It provides scheduling, task management, timing, IPC and runtime diagnostics.
Does ZenOS use a fixed maximum task count?
The current design does not define an OS_KERNEL_MAX_TASKS configuration constant or a fixed task table. Task resources are statically allocated, while the number of created tasks is constrained by the implementation, task-ID representation and available memory.
How are priorities configured?
The default configuration provides 16 priority slots and supports a configurable range of 2–256 slots. Priority 0 is reserved for the idle task; application priorities occupy the remaining configured range, with larger numeric values representing higher priority.
What scheduling model does ZenOS use?
The kernel uses a ready bitmap and per-priority task queues. It evaluates configured priorities and queue state when selecting eligible work; the implementation should not be interpreted as an constant-time scheduler independent of the configured priority range.
What timing defaults are used?
The default kernel tick period is 100 µs, configurable within the supported 100–1000 µs range. The configuration macro defaults the task stack request to 128 bytes; task creation enforces an effective minimum allocation of 256 bytes. Actual stack sizing must be verified on the target build.
What IPC features are available?
ZenOS includes events, mutexes, bounded queues and semaphores for task synchronization and communication. Mutexes use IPC priority-ceiling behavior rather than priority inheritance.
Does ZenOS support safety mechanisms?
Yes. Configurable mechanisms include watchdog support, MPU integration where supported, CRC checks, bounded RAM integrity testing, task integrity checks, stack monitoring and deadline monitoring. These features are configuration and engineering mechanisms, not automatic certification.
Is ZenOS safety certified?
No. ZenOS itself is not claimed to be certified to IEC 62304, IEC 61508, ISO 26262 or DO-178C. Product teams remain responsible for system-level verification, validation, traceability and applicable regulatory requirements.
Where can I learn more?
Start with the complete documentation guide, review the current implementation page, explore the STM32 RTOS technical page, or browse the GitHub repository.