LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 02-29-2004, 03:29 PM   #1
Scorched
LQ Newbie
 
Registered: Feb 2004
Location: Tulsa, OK USA
Distribution: Slackware
Posts: 10

Rep: Reputation: 0
Kernel System.map


Hello,

I'm wanting to re-compile my kernel, and keep the original one as well since I don't usually get it right the first time. I've been using a very informative kernel guide at digitalhermit however, I've gotten to this part and am confused:

$cp arch/i386/boot/bzImage /boot/bzImage-KERNEL_VERSION
$cp System.map /boot/System.map-KERNEL_VERSION
$ln -s /boot/System.map-KERNEL_VERSION /boot/System.map

I know the original kernel will still be there, and the LILO entry won't be changed except for a new image choice, but won't the step above replace the symbolic link of the original kernel, and mess things up? I'm just having trouble trying to figure out how I can have both the old kernel and the new kernel as choices when it seems there's only room for one System.map. If you could help me, I would greatly appreciate it. Thanks.

Regards,
Scorched
 
Old 03-01-2004, 11:53 PM   #2
ilikejam
Senior Member
 
Registered: Aug 2003
Location: Glasgow
Distribution: Fedora / Solaris
Posts: 3,109

Rep: Reputation: 96
Hi.

System.map isn't all too important when you're just running programs. Just re-link /boot/System.map to the System.map which is from the kernel you're running when you switch kernels.

I'm always forgetting to relink System.map when I change kernel (between 2.4 and 2.6), and I've never had any problems.

Dave
 
Old 03-02-2004, 12:27 AM   #3
jong357
Senior Member
 
Registered: May 2003
Location: Columbus, OH
Distribution: DIYSlackware
Posts: 1,914

Rep: Reputation: 52
Heres a novel idea.... Keep everything seperate.....

mkdir /boot/MyNewSpiffyKernel
cp arch/i386/boot/bzImage /boot/MyNewSpiffyKernel/bzImage
cp System.map /boot/MyNewSpiffyKernel/System.map

screw the symlink... It's not important. It'll read from an original just fine. Then just append your bootloader so it has the right path....
 
Old 03-02-2004, 12:49 AM   #4
Demonbane
LQ Guru
 
Registered: Aug 2003
Location: Sydney, Australia
Distribution: Gentoo
Posts: 1,796

Rep: Reputation: 47
I'm not exactly sure about 2.4 kernel, but I know for 2.6 /boot/System.map-<kernel version> gets used if present, therefore you don't need to have a symlink /boot/System.map linking to current running kernel. If memory serves that is true for 2.4 as well, can someone verify that?
But then again as ilikejam mentioned its not critical to have System.map in /boot.
 
Old 03-02-2004, 06:48 PM   #5
urka58
Member
 
Registered: Nov 2003
Distribution: slackware 14
Posts: 540

Rep: Reputation: 32
System.map is a file used by the kernel "to map" the system.
It is used by klogd that passes those parameters to syslogd in order to produce the log messages at boot.
klogd looks in / /boot /usr/src/linux-x.x.x to find out a proper System.map file (not shure in this order). You can rename the System.map produced by the new kernel compilation to System.map-2.6.3, for instance, and it will automatically recognized at boot since it has versioning features.
If wrong it doesn't affect kernel booting, but if it doesn't match the proper kernel you'll be noticed a wrong System.map is in use.
No problems if you're not interested to log messages.
System.map is used by some emulation software as well.
Hope this helps
Ciao
 
  


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
Compilling a new kernel, System.map and modules mimithebrain Linux - General 2 10-22-2005 06:07 PM
Compile kernel: System.map? iaMMai Linux - Newbie 9 05-19-2005 09:05 AM
Custom Kernel and System.map tmoorman Linux - Software 6 10-23-2003 05:12 PM
Custom kernel and System.map tmoorman Mandriva 1 10-22-2003 09:11 PM
Kernel images and System.map Dark_Helmet Linux - Newbie 4 02-03-2003 11:58 AM


All times are GMT -5. The time now is 09:13 PM.

Main Menu
Advertisement
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
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration