U30 netinst: can't boot kernel

[Giulio Sichel <cypher@tiscali.it>]

I get the following errors while booting kernel with every netinst CD  
I've
downloaded:

Warning: unable to open an initial console.
Unimplemented SPARC system call 188
Unimplemented SPARC system call 188
Kernel panic: Attempted to kill init!
 Press L1-A to return to the boot prom

Any idea? The system is an Ultra 30 with Elite3D and Creator  
framebuffers.

Thank you