It won't boot - unknow or corrupted file system

[Eduardo M. A. M. Mendes]

Hello

I am trying to install 9.1 ppc on an Ibook.  The installation went fine, 
despite some problems with bootstrap (I created an Applet boot partition or 
something like that).  

When I try to boot the ibook, I first get a menu 

linux (l)
cdrom (c)
openfirmware (o)

If I choose ¨l¨ yaboot comes out.  When boot finally tries to load the kernel, 
the following error message comes out:

hd:8,/vmlinuz-2.4.21-0.13mdk: unknown or corrupedt filesystem.

What did I do wrong?

Many thanks

Ed