LinuxQuestions.org
Support LQ: Use code LQ3 and save $3 on Domain Registration
Go Back   LinuxQuestions.org > Forums > Non-*NIX Forums > Programming
User Name
Password
Programming This forum is for all programming questions.
The question does not have to be directly related to Linux and any language is fair game.

Notices

Reply
 
Search this Thread
Old 08-30-2008, 07:53 AM   #1
Raynus
Member
 
Registered: Apr 2007
Location: BKK, Thailand
Distribution: Gentoo 10.1
Posts: 112
Blog Entries: 2

Rep: Reputation: 15
Smile Can someone give me the definition of "Kernel Symbol" and "EXPORT_SYMBOL" ??


After searching google & readng O'Reiley Linux Device Driver

i still don't get the point.

Can someone give me the definition of "Kernel Symbol" and "EXPORT_SYMBOL" ??

Thanksyou in advance

cheers
 
Old 08-30-2008, 08:04 AM   #2
pinniped
Senior Member
 
Registered: May 2008
Location: planet earth
Distribution: Debian
Posts: 1,732

Rep: Reputation: 50
A kernel symbol can mean any symbol (variable, routine, etc) in the kernel, but is probably understood to be all the routines available to the user (cat /proc/kallsyms). Exported symbols are symbols which each device driver (or other kernel routine) makes available to the rest of the kernel. This is necessary because some drivers need to share information between them, but generally all symbols in a module are hidden from the rest of the kernel (to avoid the 'namespace pollution' problem). So, for example, any routines and variables in a device driver which need to be accessible to another device driver will have the EXPORT_SYMBOL macro to export it (or EXPORT_GPL_SYMBOL if the author only wants that information to be available to GPL drivers and not non-free drivers).

Last edited by pinniped; 08-30-2008 at 08:06 AM.
 
Old 08-30-2008, 07:19 PM   #3
Raynus
Member
 
Registered: Apr 2007
Location: BKK, Thailand
Distribution: Gentoo 10.1
Posts: 112
Blog Entries: 2

Original Poster
Rep: Reputation: 15
Thats clear

thanks pinniped
 
  


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
Telling people to use "Google," to "RTFM," or "Use the search feature" Ausar General 77 03-21-2010 11:26 AM
net working eth0 eth1 wlan0 "no connection" "no LAN" "no wi-fi" Cayitano Linux - Newbie 5 12-09-2007 07:11 PM
Standard commands give "-bash: open: command not found" even in "su -" and "su root" mibo12 Linux - General 4 11-11-2007 10:18 PM
LXer: Displaying "MyComputer", "Trash", "Network Servers" Icons On A GNOME Desktop LXer Syndicated Linux News 0 04-02-2007 08:31 AM
avgscan "relocation error" "undefined symbol: __dynamic_cast_2" Monster_user Linux - Software 0 02-22-2006 11:57 AM


All times are GMT -5. The time now is 01:45 PM.

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