Developer | Dresden Real-Time Operating System Project |
---|---|
Written in | C |
OS family | Linux kernel |
Working state | current |
Source model | Open source |
Initial release | 5 October 1997 |
Latest release | 6.10 / August 2024 |
Platforms | IA-32, x86-64, ARM |
Kernel type | Monolithic on microkernel |
License | GNU General Public License |
Official website | l4linux |
L4Linux is a variant of the Linux kernel for operating systems, that is altered to the extent that it can run paravirtualized on an L4 microkernel, where the L4Linux kernel runs a service. L4Linux is not a fork but a variant and is binary compatible with the Linux x86 kernel, thus it can replace the Linux kernel of any Linux distribution.
L4Linux is being developed by the Dresden Real-Time Operating System Project (DROPS) to allow real-time and time-sharing programs to run on a computer in parallel at the same time.
L4Linux also allows setting up a virtualized environment vaguely similar to Xen or Kernel-based Virtual Machine (KVM), but a few significant differences exist[ further explanation needed ] between the intent of Xen and L4Linux.
L4Android [1] is a fork of L4Linux which encompasses the modifications to the main-line Linux kernel for Android. It is a joint project of the operating systems group of the Dresden University of Technology and the chair for Security in Telecommunications of Technische Universität Berlin.
In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and other computer programs to access hardware functions without needing to know precise details about the hardware being used.
GNU Hurd is a collection of microkernel servers written as part of GNU, for the GNU Mach microkernel. It has been under development since 1990 by the GNU Project of the Free Software Foundation, designed as a replacement for the Unix kernel, and released as free software under the GNU General Public License. When the Linux kernel proved to be a viable solution, development of GNU Hurd slowed, at times alternating between stasis and renewed activity and interest.
In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, thread management, and inter-process communication (IPC).
L4 is a family of second-generation microkernels, used to implement a variety of types of operating systems (OS), though mostly for Unix-like, Portable Operating System Interface (POSIX) compliant types.
User-mode Linux (UML) is a virtualization system for the Linux operating system based on an architectural port of the Linux kernel to its own system call interface, which enables multiple virtual Linux kernel-based operating systems to run as an application within a normal Linux system. A Linux kernel compiled for the um architecture can then boot as a process under another Linux kernel, entirely in user space, without affecting the host environment's configuration or stability.
RTLinux is a hard realtime real-time operating system (RTOS) microkernel that runs the entire Linux operating system as a fully preemptive process. The hard real-time property makes it possible to control robots, data acquisition systems, manufacturing plants, and other time-sensitive instruments and machines from RTLinux applications. The design was patented. Despite the similar name, it is not related to the Real-Time Linux project of the Linux Foundation.
Xen is a free and open-source type-1 hypervisor, providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently. It was originally developed by the University of Cambridge Computer Laboratory and is now being developed by the Linux Foundation with support from Intel, Citrix, Arm Ltd, Huawei, AWS, Alibaba Cloud, AMD, Bitdefender and EPAM Systems.
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XNU is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the Mac OS X operating system and released as free and open-source software as part of the Darwin OS, which, in addition to being the basis for macOS, is also the basis for Apple TV Software, iOS, iPadOS, watchOS, visionOS, and tvOS.
A hypervisor, also known as a virtual machine monitor (VMM) or virtualizer, is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the same kernel.
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Gernot Heiser is a Scientia Professor and the John Lions Chair for operating systems at UNSW Sydney, where he leads the Trustworthy Systems group (TS).
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Open Kernel Labs is a privately owned company that develops microkernel-based hypervisors and operating systems for embedded systems. The company was founded in 2006 by Steve Subar and Gernot Heiser as a spinout from NICTA. It was headquartered in Chicago, while research and development was located in Sydney, Australia. The company was acquired by General Dynamics in September 2012.
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The NetBSD rump kernel is the first implementation of the "anykernel" concept where drivers either can be compiled into or run in the monolithic kernel or in user space on top of a light-weight kernel. The NetBSD drivers can be used on top of the rump kernel on a wide range of POSIX operating systems, such as the Hurd, Linux, NetBSD, DragonFly BSD, Solaris kernels and even Cygwin, along with the file system utilities built with the rump libraries. The rump kernels can also run without POSIX directly on top of the Xen hypervisor, an L4 microkernel using the Genode OS Framework or even on "OS-less" bare metal.
Genode is a free and open-source software operating system (OS) framework consisting of a microkernel abstraction layer and a set of user space components. The framework is notable as one of the few open-source operating systems not derived from a proprietary OS, such as Unix. The characteristic design philosophy is that a small trusted computing base is of primary concern in a security-oriented OS.