yaboot from USB & SATA drives

[Paul Nasrat]

2009/3/3 Stephan <geek at wickedclips.net>:
> 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.)

I assume you've seen that OF can see the USB disk - boot with it
attached and either examine /proc/device-tree or boot into OF and look
around:

eg /pci at f2000000/pci-bridge at d/usb at 9/disk at 1

There may be a devalias depending on your firmware version.

> 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?

There are two ways to do this with different partition table types (PC
or Mac), I've definiately automated this in the past - note the offset
in the script where I document one way to do this may nott work for
you if you're using different sizings, but we should be able to
automate that to multiply the start block of the ext2 partition by
block size eg parted ppcboot.img unit b print :

http://lists.penguinppc.org/yaboot-devel/2005/yaboot-devel-200506/msg00036.html

You probably just want /boot and the Apple_Bootstrap/yaboot on the usb disk.

I think there is a better way I've got scripted too but will need to
dig through my stuff.