A hardware abstraction layer is a component of an operating system that functions something like an API. (In strict technical architecture, hardware abstraction layers reside at the device level, a layer below the standard API level.) It allows programmers to write applications and game titles with all the device-independent advantages of writing to an API, but without the large processing overhead that APIs normally demand.
HAL allows developers to access hardware devices without explicit knowledge of the brand's model or its details and works in conjunction with DirectDraw.
A thin layer of software provided by the hardware manufacturer that hides, or abstracts, hardware differences from higher layers of the operating system. Through the filter provided by the HAL, different types of hardware all look alike to the rest of the operating system. This allows Windows NT and Windows 2000 to be portable from one hardware platform to another. The HAL also provides routines that allow a single device driver to support the same device on all platforms. The HAL works closely with the kernel.
Virtualizes hardware interfaces, making the hardware dependencies transparent to the rest of the operating system. This allows Windows NT to be portable from one hardware platform to another.
The portion of the operating system that lets programs deal with hardware directly. This allows programs needing more speed from the computer to bypass...
Firmware, which provides a semi- or fully standardized interface between a SOC and code designed to exercise the SOC. This code forms a layer between the hardware and software, allowing any software that uses a HAL to be more easily ported to operate with a different SOC. This may or may not include boot code.
In operating systems such as Windows NT, a layer in which assembly language code is isolated. A hardware abstraction layer functions similarly to an application programming interface (API) and is used by programmers to write device-independent applications. See also application programming interface (API) and device independence.
An NT-based operating system component that provides platform-specific support for the NT kernel, the I/O Manager, kernel-mode debuggers, and the lowest-level device drivers. The HAL exports routines that abstract platform-specific hardware details about caches, I/O buses, interrupts, and so forth, and provides an interface between the platform's hardware and the system software. For example, the HAL implements a routine to map each device driver's bus-relative device interrupt vector to a system-assigned vector with a corresponding platform-specific hardware priority (DIRQL), as well as several routines that provide DMA-transfer support.
A hardware abstraction layer (HAL) is an abstraction layer, implemented in software, between the physical hardware of a computer and the software that runs on that computer. Its function is to hide differences in hardware from most of the operating system kernel, so that most of the kernel-mode code does not need to be changed to run on systems with different hardware. A HAL allows instructions from higher level computer languages to communicate with lower level components, such as directly with hardware.