On Tuesday, October 7, 2003, at 12:03  PM, Henry B. Hotz wrote:

> At 8:36 PM +0200 10/1/03, Xavier HUMBERT wrote:
>> Michael Wolfson <michael@nosflow.com> wrote:
>>
>>>  > OF 3 machines have the ability to change boot disk (or even 
>>> partition)
>>>  > by holdign down the option- (or alt-) key during start up. Does 
>>> NetBSD
>>>  > support this? If not, what is lacking?
>>>
>>>  No, it would need some magic.  Most of that magic is detailed in the
>>>  snag-key boot CD creation HOW-TO:
>>>
>>>  http://www.netbsd.org/Documentation/bootcd.html
>>
>> Well, if I unnderstand that correctly, creating a small bootstrap
>> partition, with a "fake system" containing the CHRP magic script will
>> allow to choose Partitions an OSes at boot time ?
>
> There is an interesting thread near the beginning of August on 
> darwin-development, subject: "OpenFirmware hack to prevent ndrv from 
> loading?" which includes the pointer for how to do this.
>
> Figuring out the Forth code to actually do what you want is usually 
> the hard part, but maybe not in this case.  It's just a boot command 
> isn't it?

Look at PR 11435 in port-macppc.  Another good place to find 
information on this is in the yaboot files and man pages in Yellow Dog 
Linux.  At one time I had a modified version of the yaboot CHRP script 
that worked just like the boot selector in the i386 port.  
Unfortunately my disk crashed and I didn't have a recent backup.

-bob