yaboot from USB & SATA drives

[Stephan]

Hi there folks,

I've been banging my head against this for a week now, have searched 
hundreds of pages, and still haven't quite figured this out.

I have four happy healthy Mac G4s, with ancient and dying EIDE hard 
drives.  As I expect the machines to live close to another half decade, 
I'm trying to create a system where they can boot to my SATA hard 
drives, without an EIDE drive.  I've successfully installed yaboot to 2 
gig usb pen drives, which is suitable for installing the base system 
(I'm using Debian Etch) but as Open Firmware can't see my PCI SCSI 
controller (though the Debian installer can) I'd like to install a 'boot 
only' system to the USB drive, with the SATA drives holding the bulk of 
my data.  I'm not trying to specifically set up a RAID system (at this 
time.)

What I haven't been able to figure out, is how to set up the pen drive 
to hold both the yaboot, and necessary boot/startup directories.  Any 
suggestions?

Thank you kindly,

Stephan