Editing Hardware abstraction (section)

{{redirect|Hardware Abstraction Layer|the UNIX-like operating system subsystem|HAL (software)}}
{{short description|Sets of routines in software}}
{{Use dmy dates|date=March 2023}}
'''Hardware abstractions''' are sets of routines in [[Computer software|software]] that provide programs with access to [[Computer hardware|hardware]] resources through programming interfaces. The programming interface allows all devices in a particular class ''C'' of hardware devices to be accessed through identical interfaces even though ''C'' may contain different subclasses of devices that each provide a different hardware interface.

Hardware abstractions often allow programmers to write [[Computer hardware|device]]-independent, high performance applications by providing standard [[operating system]] (OS) calls to hardware. The process of [[Abstraction (computer science)|abstracting]] pieces of hardware is often done from the perspective of a [[Central processing unit|CPU]]. Each type of CPU has a specific [[instruction set architecture]] or ISA. The ISA represents the primitive operations of the machine that are available for use by [[assembly language|assembly]] programmers and compiler writers. One of the main functions of a [[compiler]] is to allow a programmer to write an algorithm in a [[high-level language]] without having to care about CPU-specific instructions. Then it is the job of the compiler to generate a CPU-specific executable. The same type of abstraction is made in operating systems, but OS [[API]]s now represent the primitive operations of the machine, rather than an ISA. This allows a programmer to use OS-level operations (e.g. task creation/deletion) in their programs while retaining [[Software portability|portability]] over a variety of different platforms.