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

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

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....

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.

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