Debian on a BiG5

[xavier grave <grave@ipno.in2p3.fr>]

Hi,

I have already a BiG4 1Ghz running a debian. Now I have also a BiG5.  
How can I create a CD to boot such a beast ?

Some idea I had :
  - debootstrap a ppc64 on a directory on my BiG4 and use bootcdwrite
  - debootstrap a ppc32 on a directory on my BiG4 and use bootcdwrite
  - generate an installer (where do I need to go to have information
    to do so?)

I can try both 32 and 64 bits benh kernels with ppc32 debian packages  
but do the ppc64 debian packages will work with a 32 bits or 64 bits  
kernel ?

Thanks in advance for any help

xavier