HELP Re-compiled new kernel won't boot ...

[Stefan Bruda]

At 08:39 +1200 on 2002-10-3 Bernard Mentink wrote:
 >
 > I tried "cd-linux root=/devhda14" at the boot: prompt but got this error:
 > "cd-linux:2,/vmlinux: unable to open file invalid device"

I have in mind two more possible ways of getting back in business:

This is from the Yaboot man page, but I have not tested it myself:
start normally (with the yaboot from the hard drive), press TAB at the
`boot:' prompt (to stop the timer) and then type

    hd:14,/boot/vmlinux-2.4.20-pre7-ben0

Of course, change "14" to your actual partition, and
vmlinux-2.4.20-pre7-ben0 to the name of your (old and trusted) kernel.
This assumes that you have an IDE drive (SCSI paths are more complex
and I am not very sure about their sytnax...).  Oh, and I also assume
that the kernel is in the /boot directory in your Linux file tree
(change as apporpriate if you keep the kernel in other place).

If this works, see the last item in the enumeration below.

If on the other hand it does not work, boot from the rescue (aka
"tasty morsels") CD, and just press enter at the `boot:' prompt.  You
will end up in a minimal shell.  If you don't, reboot (from the CD
again) and this time type `rescue-safe' (without the quotes) at the
prompt.  Then:

o Mount the (original) root file system:

      mount -t ext2 /dev/hda14 /root

  (change hda14 to whatever your root partition is; if your root
  partition is actually ext3, replace ext2 with ext3).  

o Assuming that your kernels are in /boot, do

      cd /root/boot

  You will find yourself in the directory with the kernels (and
  symlinks).

o Restore the symlinks to point to the old and trusted kernel and its
  System.map. 

o change to /, unmount /root by doing

      umount /root

  and reboot the machine (this time from the hard drive).  You should
  end up where you started before installing the new kernel.

o Recompile your kernel, re-install it, test the thing again
  (hopefully, this time it will work), but before doing anything of
  this sort do create in /etc/yaboot.conf an entry corresponding to
  the old kernel, just in case something goes wrong (I believe I no
  longer need to tell you how important this is ;-) ).  Don't forget
  to run ybin too.

If you still have problems, contact me directly and I will provide
more details for the procedure above.

Stefan

-- 
If it was so, it might be; and if it were so, it would be; but as
it isn't, it ain't. That's logic.
    --Lewis Carroll, Through the Looking-Glass