Real-Time Operating Systems
CHERI is being explored across several embedded and real-time software models, from capability-first RTOS designs to ports of established ecosystems.
Embedded systems cover a wide range of timing, memory, power, assurance, device, and compatibility requirements. CHERI appears in this landscape through both new capability-oriented platforms and ports of established real-time operating systems.
Different routes into embedded CHERI
CHERIoT
CHERIoT co-designs a CHERI instruction-set profile, RTOS, compartment model, linker, allocator, and SDK for small embedded systems. Capability protection is part of the platform’s foundation rather than an extension to a conventional process model.
Zephyr
CHERI-enabled Zephyr brings capability state and memory protection into Zephyr’s existing kernel, APIs, drivers, configuration system, and board ecosystem. Its attraction is continuity with software already built around Zephyr.
FreeRTOS
CHERI FreeRTOS work explores capability protection and compartments around a widely deployed real-time kernel and its familiar application interfaces. The Alliance working group provides a forum for common approaches across ports and platforms.
seL4 and Microkit
seL4 is a verified microkernel rather than a conventional RTOS, but it is relevant to embedded and real-time systems that need strong isolation and assurance. CHERI work connects architectural memory capabilities with seL4’s existing capability-based kernel model and Microkit components.
What distinguishes the platforms
The projects differ in architecture profile, kernel model, compartment design, existing APIs, device support, toolchain integration, temporal-safety mechanisms, assurance evidence, and relationship with upstream communities.
Those differences reflect distinct product and research goals. They are not interchangeable implementations of one CHERI RTOS specification.
Alliance collaboration
Related groups include CHERI FreeRTOS, CHERI Zephyr, CHERI for seL4, and MMU-less Systems.