POSIXembedded

POSIXembedded is an informal designation for applying POSIX standards to embedded systems to improve software portability across devices and vendors. POSIX, Portable Operating System Interface, is a family of standards from IEEE and The Open Group that define APIs for process management, threads, synchronization, signals, IPC, file I/O, timers, and networking.

In embedded contexts, resources are limited and real-time requirements are common. Therefore POSIX support is usually a subset or profile rather than a full implementation. Developers often target POSIX subsets that fit memory and power constraints while offering portability. Real-time extensions from POSIX.1b/c are frequently emphasized for scheduling, clocks, and priority handling. Some embedded operating systems provide native POSIX layers or require a POSIX-certified RTOS component.

Common platforms include Linux-based embedded systems, which are broadly POSIX-compliant, and dedicated RTOSes that expose a POSIX API through a compatibility layer. There are also smaller runtimes that implement parts of POSIX, notably pthreads, signals, and timers.

The term does not correspond to a single formal standard. Instead, it describes the practice of adopting POSIX APIs in a constrained environment. Benefits include easier code reuse, broader toolchain support, and better interoperability. Drawbacks can include increased memory usage, partial feature coverage, and variability in concrete implementations.

See also: POSIX, IEEE 1003, The Open Group, POSIX.1-2008, RTOS, Linux, FreeRTOS, RTEMS.