PX5 RTOS vs RT-Thread

PX5 RTOS is a hard real-time operating system for resource-constrained embedded applications, with a native POSIX pthreads API. It is presented for safety-critical work in automotive, industrial, medical, rail, and other demanding settings. The maker says a minimal setup on typical 32-bit microcontrollers can use as little as 1KB of flash and 1KB of RAM. At 80MHz, most API calls and context switches are stated to take less than one microsecond; processing is described as predictable and independent of the number of active threads. Stated certifications include IEC 61508 SIL 4, IEC 62304 Class C, ISO 26262 ASIL D, and EN 50128 SW-SIL 4. Run-time checks cover function pointers, system objects, buffers, and stacks. Supported architectures include Arm Cortex-M, Cortex-R and Cortex-A, RISC-V, Renesas RX, AMD MicroBlaze, and Infineon TriCore. Listed tools include IAR, Eclipse/GCC, Arm DS, and Arm Keil. Pricing is on request; listed packages start at 5000.00 USD as a one-time fee or $5,000 a year for a subscription. Free evaluation kits are available with a free PX5 Community login.

RT-Thread has no write-up on Specifiction yet; its figures are above.