LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices

Reply
 
Search this Thread
Old 06-23-2013, 04:40 AM   #1
[ITA]freeware
Member
 
Registered: Jul 2004
Distribution: Debian wheezy
Posts: 74

Rep: Reputation: 15
hal vs udev vs udisks


Hi folks,

i'm trying to understand how user space devices managing is provided in linux (Debian wheezy). I'm googling by days to understand what are hal, udisks and udev, but i'm feeling so stupid for i cannot really figure out what they are and what they do. I understood only that udisks in a sort of configuration client for udev, which rules (for what?) can be configured properly via a udisks configuration file.

Can someone provide me a udev/udisks/hal guide for dummies?
 
Old 06-25-2013, 05:55 PM   #2
slipstreamed
Member
 
Registered: Nov 2010
Posts: 56

Rep: Reputation: 24
On typical Linux-based systems, the /dev directory is used to store file-like device nodes which refer to certain devices in the system. Each node points to a part of the system (a device), which might or might not exist. Userspace applications can use these device nodes to interface with the systems hardware, for example, the X server will "listen to" /dev/input/mice so that it can relate the user's mouse movements to moving the visual mouse pointer.
The original /dev directories were just populated with every device that might possibly appear in the system. /dev directories were typically very large because of this. Devfs came along to provide a more manageable approach (noticeably, it only populated /dev with hardware that is plugged into the system) but the system proved to have problems which could not be easily fixed.
udev vs devfs:
http://lwn.net/Articles/65197/
https://www.kernel.org/doc/ols/2003/...es-249-257.pdf

udev is the "new" way of managing /dev directories, designed to clear up some issues with previous /dev implementations, in order to create and name /dev device nodes corresponding to devices that are present in the system, udev relies on matching information provided by sysfs with rules provided by the user.
sysfs is a new filesystem to the 2.6 kernels. It is managed by the kernel, and exports basic information about the devices currently plugged into your system. udev can use this information to create device nodes corresponding to your hardware. sysfs is mounted at /sys

http://www.linux.com/news/hardware/p...ls/180950-udev
http://www.redhat.com/magazine/003jan05/features/hal/
http://www.enterprisenetworkingplane...-with-udev.htm
 
1 members found this post helpful.
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
hal and udev can't find version paddeo Slackware 5 04-12-2007 12:46 PM
What is relationship between udev and hal in etch? acanton Debian 9 02-23-2006 02:40 PM
HAL/UDEV ! I need help to get them working ! kevkim55 Suse/Novell 1 01-15-2006 05:57 AM
Multifunction support - Hal and Udev flebber Linux - Hardware 1 06-18-2005 09:44 PM
udev/hal, problems... TazG Linux - Hardware 0 09-28-2004 02:38 PM


All times are GMT -5. The time now is 05:31 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration