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

[Bernard mentink]

  Hi Stefan,

Success! :-) I found I had to boot the kernel this way:

1. On startup, at the Yaboot prompt (boot:) typed help.
2. Typed /pcixxxxxxxxxxxxxxxx:14,/boot/vmlinux-2.4.19-4a root=/dev/hda14

The "xxxxx" in the above is the OpenFirmware drive path (displayed by 
help), the 14 is my root partition, then
the path to my old stable kernel, then the root path for the kernel.

After typing all that, I booted on my old kernel, phew ..... :-[

Many thanks for your folks suggestions, I'm still not sure why the other 
method did not work.

Stefan, just got your reply. Seems you have a shorter way of achieving 
the same thing, I will try this too(for my own knowledge).

I also re-compiled the kernel, after reading in the distribution .config 
to xconfig (and then puting in my mods),
that worked fine, and my kernel runs as before. And yes, I did do the 
right thing with yaboot.conf this time. :-[ :-[

Cheers,
Bernie

Stefan Bruda wrote:

>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
>