downgrade from ipod 6g firmware

[eigenmaster]

I understand that the 6G firmware on the Ipod Classic cannot be cracked, and therefore it is impossible to install rockbox (or ipodlinux).

However is this possible?

1) downgrade the Classic to Apple 5G firmware (flash it?)
2) then install Rockbox

I am just trying to figure this out, so patience with my question is appreciated.

[linuxstb]

It's not just the new firmware - the internal hardware on the Classic is completely different to the older ipods, so old firmwares (either Apple's or Rockbox) simply won't work.