restoring the default kernel (lynn.newton@cox.net)

[Craig S.]

On Friday 12 April 2002 16:30, you wrote:

> Message: 2
> From: <lynn.newton@cox.net>
> To: plug-discuss@lists.plug.phoenix.az.us
> Subject: restoring the default kernel
> Date: Fri, 12 Apr 2002 15:48:52 -0400
> Reply-To: plug-discuss@lists.plug.phoenix.az.us
>
> Is it a true statement that if I do an upgrade of
> 7.2 => 7.2 (yes, the same version) that I will replace
> the kernel-related files as installed in a normal
> upgrade?
>

not sure what you mean here. I assume you are just trying to use a 2.4 kernel 
instead of  the 2.2 kernels that seem to load as the default during install 
of most distros. I believe that if you don't want to mess with installing a 
2.2 kernel and your distro gives you the source for a 2.4 kernel also then 
when booting the install cd and you are at the boot option you can pass a 
parameter to install your 2.4 kernel instead of the 2.2 kernel.

> In my frustration to untangle a problem on my system I
> tried to recompile my kernel and may have managed to
> hose myself pretty good, because I think I may have
> deleted something I need. 
did you copy the newly compiled kernel bzImage image to /vmlinuz or 
/boot/vmlinuz? If so did you overwrite the original kernel image when you 
copied bzImage? 
Usually I follow the recommendations in the kernel-compile-how-to. It 
recommends you copy the newly compiled image as vmlinuz-2.x.xx where 2.x.xx 
is the kernel version. Then you add the new kernel image to lilo's boot list 
and finally run /sbin/lilo. Oh yeah I usually make the boot label in 
lilo.conf as just the kernel version but you can name it Big Bird for all I 
care, as long as you can relate the name to the kernel image. Now when you 
reboot if your new kernel image is boned then when you reboot you can just 
load the default (original kernel) kernel and check your syslogs and stuff to 
figure out what is busted.

However, the only stuff I
> deleted is in /usr/src, not any thing in /boot (I don't
> *think*), so assuming I haven't also splattered my
> lilo.conf, I should still be all right. Right?
Well if your killed usr/src you just blew away all your kernel sources which 
means you have no way to compile any new kernel images until you get a new 
kernel tarball and unpack it.
Just mkdir /usr/src
look on your distro sources cd for the kernel tarballs.
copy them from the cd to /usr/src
unpack the tarballs.
link /usr/src/linux to whatever kernel source dir you want
cd /usr/src/linux
compile your new kernel and follow the how to for compiling kernels.
your doc files should be in /usr/doc and can be read from command line by 
typing "vi docfile" or "pico docfile".

Not sure about your kernel image, it depends on how you copied the image into 
the root or boot dirs. Best thing to do is recall the exact sequence of steps 
and what you typed when trying your kernel compile. This would help to figure 
out exactly what you did.

>
> I do believe that I'll be able to reboot right now, but
> am afraid to try unless I know that if the worst happens
> I can restore things by booting from CD and doing an
> upgrade.
>
yes you can but in the future a cdrom with your actual bootfiles and basic 
utilites might be nice also.

> And yes, I know this is not the cool way to be making
> kernel changes. I just inadvertently botched a step in
> the process so now I'm being extra cautious. No kernel
> means no system.

no kernel means no drivers. At the very basic level yes there is not anything 
to intrepret system device calls and such to the OS so the OS is pretty much 
dysfunctional at that point because the OS can no longer talk to your 
hardware.

Good luck


Craig S.