Kudzu loads modules, generates dev links. One widely used hardware autodetection and probing tool is ?Kudzu. Hotplug doesn't have it's own database of module mappings (it uses the running kernel's modules.*map) and will therefore never get outdated.Ĭurrently, Hotplug is the only mature software to handle hotplug. The development of Discover is led by Progeny and it has its own homepage.Įven though hotplug wasn't mean to handle coldplugging it can handle it nowadays. In Etch, it installs discover1 and udev by default.

Entries here can be made by hand using command line utilities, or by an automated utility such as DevFS or udev.In Sarge, DebianInstaller installs discover and ?hotplug by default. This, and more, is all described in the HAL specification.Įntries in /dev give access to the devices the kernel drives. Finally, HAL provides some monitoring (in an unintrusive way) of devices presently ethernet link detection and volume mounts are monitored. HAL provides a network API through D-BUS for querying devices and notifying when things change. HAL tries to understand both physical devices (such as PCI, USB) and the device classes (such as input, net and block) physical devices have, and allows merging of information from so called device info files specific to a device. HAL is a hardware abstraction layer and aims to provide a live list of devices present in the system at any point in time. These attributes may be used as keys to determine a unique name for the device. On device creation, udev reads the sysfs directory of the given device to collect device attributes. As part of the hotplug subsystem, udev is executed if a kernel device is added or removed from the system. udev replaces the devfs of the 2.4 kernel.įrom the udev man page. New with the 2.6 kernel, udev automates the creation and removal of devices in /dev.

The scripts load kernel modules and user scripts when new hardware is seen. The kernel calls the /sbin/hotplug script when it sees new hardware passing several arguments. Sysfs exports information about devices and drivers from the kernel device model to userspace, and is also used for configuration. Sysfs is a virtual file system provided by the 2.6 Linux kernel. Kernel and kernel modules drive the devices. There is a hierarchy to the various systems. It won't tell you how to create devices or have scripts run when new devices are added.

It will hopefully give you enough of the big picture to better understand the man pages and documentation for the specific subsystems. This page aims to give a rough overview of the various subsystems used in linux to manage devices. Translation(s) : English - Français - Italiano

Device manager in linux