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Sysfs
sysfs is a pseudo file system provided by the Linux kernel that exports information about various kernel subsystems, hardware devices, and associated device drivers from the kernel's device model to user space through virtual files. In addition to providing information about various devices and kernel subsystems, exported virtual files are also used for their configuration. sysfs provides functionality similar to the sysctl mechanism found in BSD operating systems, with the difference that sysfs is implemented as a virtual file system instead of being a purpose-built kernel mechanism, and that, in Linux, ''sysctl'' configuration parameters are made available at ''/proc/sys/'' as part of procfs, not sysfs which is mounted at ''/sys/''. History During the 2.5 development cycle, the Linux driver model was introduced to fix the following shortcomings of version 2.4: * No unified method of representing driver-device relationships existed. * There was no generic hotplug mechanism. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sysctl
sysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled programs, and an administrator command for interactive use and scripting. Linux additionally exposes sysctl as a virtual file system. BSD In BSD, these parameters are generally objects in a management information base (MIB) that describe tunable limits such as the size of a shared memory segment, the number of threads the operating system will use as an NFS client, or the maximum number of processes on the system; or describe, enable or disable behaviors such as IP forwarding, security restrictions on the superuser (the "securelevel"), or debugging output. In OpenBSD and DragonFly BSD, sysctl is also used as the transport layer for the hw.sensors framework for hardware monitoring, whereas NetBSD uses the ioctl system call for its sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HAL (software)
HAL (Hardware Abstraction Layer or rather Hardware Annotation Library) is a software subsystem for UNIX-like operating systems providing hardware abstraction. HAL is now deprecated on most Linux distributions and on FreeBSD. Functionality is being merged into udev on Linux as of 2008–2010 and devd on FreeBSD. Previously, HAL was built on top of udev. Some other OS-es which don't have an alternative like udev or devd still use HAL. The purpose of the hardware abstraction layer was to allow desktop applications to discover and use the hardware of the host system through a simple, portable and abstract API, regardless of the type of the underlying hardware. HAL for Linux OS was originally envisioned by Havoc Pennington. It became a freedesktop.org project, and was a key part of the software stack of the GNOME and KDE desktop environments. It is free software, dual-licensed under both the GNU General Public License and the Academic Free License. HAL is unrelated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudo File System
In computer science, a synthetic file system or a pseudo file system is a hierarchical interface to non-file objects that appear as if they were regular files in the tree of a disk-based or long-term-storage file system. These non-file objects may be accessed with the same system calls or utility programs as regular files and directories. The common term for both regular files and the non-file objects is ''node''. The benefit of synthetic file systems is that well-known file system semantics can be reused for a universal and easily implementable approach to interprocess communication. Clients can use such a file system to perform simple file operations on its nodes and do not have to implement complex message encoding and passing methods and other aspects of protocol engineering. For most operations, common file utilities can be used, so even scripting is quite easy. This is commonly known as everything is a file and is generally regarded to have originated from Unix. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. In general, the term is used as large in relation to contemporaneous hard disk drives, but it has been used large in relation to primary memory as for example with floppy disks on personal computers. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, and a variety of computer drives such as hard disk drives, magnetic tape drives, magneto-optical disc drives, optical disc drives, memory cards, and solid-state drives. It also includes experimental forms like holographic memory. Mass storage includes devices with removable and non-removable media. It does not include random access memory (RAM). There are two broad classes of mass storage: local data in devices such as smartphones or computers, and enterprise servers and data centers for the cloud. For local storage, SSDs are on the way to replacing HD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interfaces Of The Linux Kernel
Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Interface: A Journal for and About Social Movements'' * ''Interfaces'' (journal), now ''INFORMS Journal on Applied Analytics'' Arts and entertainment * ''Interface'' (album), by Dominion, 1996 * Interface (band), an American music group * ''Interface'' (film), a 1984 American film * ''Interface'' (novel), by Stephen Bury (a pseudonym), 1994 * "Interface" (''Star Trek: The Next Generation''), an episode of the TV series * ''Interface series'', a science fiction horror story in short installments on Reddit Science, social science and technology Computing and electronics * Interface (computing), a shared boundary between system components ** Interface (Java) ** Interface (object-oriented programming) ** Application binary interface, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Special-purpose File Systems
Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procure political rights, as for a disenfranchised group * Free will, control exercised by rational agents over their actions and decisions * Free of charge, also known as gratis. See Gratis vs libre. Computing * Free (programming), a function that releases dynamically allocated memory for reuse * Free format, a file format which can be used without restrictions * Free software, software usable and distributable with few restrictions and no payment * Freeware, a broader class of software available at no cost Mathematics * Free object ** Free abelian group ** Free algebra ** Free group ** Free module ** Free semigroup * Free variable People * Free (surname) * Free (rapper) (born 1968), or Free Marie, American rapper and media personality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tmpfs
tmpfs (short for Temporary File System) is a temporary file storage paradigm implemented in many Unix-like operating systems. It is intended to appear as a mounted file system, but data is stored in volatile memory instead of a persistent storage device. A similar construction is a RAM disk, which appears as a virtual disk drive and hosts a disk file system. Semantics Everything stored in tmpfs is temporary in the sense that no files will be directly created on non-volatile storage such as a hard drive (although swap space is used as backing store in case of low memory situations). On reboot, everything in tmpfs will be lost. The memory used by tmpfs grows and shrinks to accommodate the files it contains. Many Unix distributions enable and use tmpfs by default for the branch of the file system or for shared memory. This can be observed with as in this example: Filesystem Size Used Avail Use% Mounted on tmpfs 256M 688K 256M 1% /tmp Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Configfs
Configfs is a RAM-based virtual file system provided by the 2.6 Linux kernel. Details Configfs appears similar to sysfs but they are in fact different and complementary. Configfs is for creating, managing and destroying kernel objects from user-space, and sysfs for viewing and manipulating objects from user-space which are created and destroyed by kernel space. It is typically mounted at /sys/kernel/config (or more rarely at /config). See also *tmpfs *sysctl sysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled ... – an interface for examining and dynamically changing parameters in the BSD and Linux operating systems References External linksConfigfs - the API [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Udev
udev (userspace ) is a device manager for the Linux kernel. As the successor of devfsd and hotplug, udev primarily manages device nodes in the directory. At the same time, udev also handles all user space events raised when hardware devices are added into the system or removed from it, including firmware loading as required by certain devices. Rationale It is an operating system's kernel that is responsible for providing an abstract interface of the hardware to the rest of the software. Being a monolithic kernel, the Linux kernel does exactly that: device drivers are part of the Linux kernel, and make up more than half of its source code. Hardware can be accessed through system calls or over their device nodes. To be able to deal with peripheral devices that are hotplug-capable in a user-friendly way, a part of handling all of these hotplug-capable hardware devices was handed over from the kernel to a daemon running in user-space. Running in user space serves security a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Module (Linux)
In computing, a loadable kernel module (LKM) is an object file that contains code to extend the running kernel, or so-called ''base kernel'', of an operating system. LKMs are typically used to add support for new hardware (as device drivers) and/or filesystems, or for adding system calls. When the functionality provided by an LKM is no longer required, it can be unloaded in order to free memory and other resources. Most current Unix-like systems and Microsoft Windows support loadable kernel modules under different names, such as kernel loadable module (kld) in FreeBSD, kernel extension (kext) in macOS (although support for third-party modules is being dropped), kernel extension module in AIX, kernel-mode driver in Windows NT and downloadable kernel module (DKM) in VxWorks. They are also known as kernel loadable modules (or KLM), and simply as kernel modules (KMOD). Advantages Without loadable kernel modules, an operating system would have to include all possible anticipated fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCV
Inter User Communication Vehicle (IUCV) is a data transfer mechanism in IBM VM line of operating systems. It was introduced with VM/SP Release 1 in 1980. It allows establishment of point to point communication channels, either between two virtual machines or between a virtual machine and hypervisor services. In effect, IUCV provides a form of message-based interaction between virtual machines that anticipated the client/server interaction between network connected physical machines that emerged later on distributed systems. IUCV is implemented by CP (the VM hypervisor) and controls all aspects of session establishments, message passing and flow control. IUCV basics Initializing IUCV Before a virtual machine can use the IUCV service, it must first indicate the address of an area within its address space where CP will be able to store information regarding pending information or status. Therefore, the DECLARE BUFFER method must be invoked first. The IUCV Path In IUCV terminology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channel Command Word
In computing, channel I/O is a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers. In the past, channels were generally implemented with custom devices, variously named channel, I/O processor, I/O controller, I/O synchronizer, or ''DMA controller''. Overview Many I/O tasks can be complex and require logic to be applied to the data to convert formats and other similar duties. In these situations, the simplest solution is to ask the CPU to handle the logic, but because I/O devices are relatively slow, a CPU could waste time (in computer perspective) waiting for the data from the device. This situation is called 'I/O bound'. Channel architecture avoids this problem by processing some or all of the I/O task without the aid of the CPU by offloading the work to dedicated logic. Channels are logically self-contained, with sufficient logic and working storage to handle I/O tasks. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
