Editing Loadable kernel module (section)

{{Short description|Dynamically loadable module that extends a running operating system kernel}}
A '''loadable kernel module''' (LKM) is an [[executable]] [[Library (computing)|library]] that [[extensibility|extends]] the capabilities of a running [[kernel (operating system)|kernel]], or so-called ''base kernel'', of an [[operating system]]. LKMs are typically used to add support for new [[computer hardware|hardware]] (as [[device driver]]s) and/or [[filesystem]]s, or for adding [[system call]]s. When the functionality provided by an LKM is no longer required, it can be unloaded in order to free [[computer storage|memory]] and other resources.

Most current [[Unix-like]] systems and [[Microsoft Windows|Windows]] support loadable kernel modules but with different names, such as '''kernel loadable module''' (kld) in [[FreeBSD]], '''kernel extension''' (kext) in [[macOS]] (although support for third-party modules is being dropped<ref>{{cite web |title=Deprecated Kernel Extensions and System Extension Alternatives |url=https://developer.apple.com/support/kernel-extensions/ |publisher=Apple Inc. |access-date=13 March 2021}}</ref>),<ref>{{cite web|url=https://developer.apple.com/library/mac/#documentation/Darwin/Conceptual/KEXTConcept/KEXTConceptIntro/introduction.html|title=Kernel Extension Programming Topics: Introduction|publisher=[[Apple Inc.]]|date=September 1, 2010|access-date=May 5, 2013|url-status=live|archive-url=https://web.archive.org/web/20130504142911/http://developer.apple.com/library/mac/#documentation/Darwin/Conceptual/KEXTConcept/KEXTConceptIntro/introduction.html|archive-date=May 4, 2013}}</ref> '''kernel extension module''' in [[AIX]], '''dynamically loadable kernel module''' in [[HP-UX]],<ref>{{cite web|url=https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c01943990|title=Managing and Developing DynamicallyLoadable Kernel Modules|publisher=[[Hewlett-Packard]]|date=June 7, 2001}}</ref> '''kernel-mode driver''' in [[Windows NT]]<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/windows/hardware/ff557272(v=vs.85).aspx|title=What Determines When a Driver Is Loaded|work=[[Microsoft Developer Network]]|publisher=[[Microsoft]]|date=November 21, 2012|access-date=May 5, 2013|url-status=live|archive-url=https://web.archive.org/web/20130306121408/http://msdn.microsoft.com/en-us/library/windows/hardware/ff557272%28v%3Dvs.85%29.aspx|archive-date=March 6, 2013}}</ref>  and '''downloadable kernel module''' (DKM) in [[VxWorks]]. They are also known as '''kernel loadable module''' (KLM), or simply as '''kernel module''' (KMOD).