Machine boots directly into Mac OS X with no yaboot boot menu

[Charles Trois]

> Message: 3
> Date: Wed, 01 Jun 2005 08:19:28 -0400
> From: mascarasnake <dontdrill at earthlink.net>
> Subject: Re: Machine boots directly into Mac OS X with no yaboot boot
> 	menu
> To: Yellow Dog Linux Newbie List
> 	<yellowdog-newbie at lists.terrasoftsolutions.com>
> 
>>The second ways is by following the instructions at this web site:
>>
>>http://penguinppc.org/bootloaders/yaboot/doc/yaboot-howto.shtml/ch9.en.shtml 
>>
>>
>>under the title "9.2 Loading Yaboot". I strt my machine and hold the 
>>Command-Option-o-f keys and the open firmware screen appears at the 
>>prompt I enter:
>>
>>0 > boot hd:2,yaboot
>>
>>and yellowdog linux starts.
>>
>>BUT I dont want to have to do this everytime to use linux, I had yaboot 
>>set up and now it is gone. Is there anything I can do to get yaboot 
>>running again so I can choose which OS to boot each time I start up?
>>
>>Thanks for reading.
>> 
> You should be able to straighten things out by simply running 'ybin' (as 
> root) once you are booted into YDL. If your 'yaboot.conf' file is set up 
> properly, this should reset the OF to recognize yaboot on the bootstrap 
> partition first.
>
Hello!

I am faced with exactly the same problem. I therefore tried the above 
solution, i.e. I gave this OF commmand:

boot hd:12,yaboot

This started the loading of Linux, but it stopped a little later with 
this error message (copied by hand):

VFS Cannot open root device "hda15" or unknown-block(0,0)
Pleased append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on 
unknown-block(0,0)
Rebooting in 180 seconds.

That has a touch of "déjà vu", but one never knows what to do about it: 
it seems that I am supposed to write "root=/dev/hda15" or perhaps 
"root=hd:15" somewhere. As a matter of fact, it is already in 
yaboot.conf, and also in the kernel (default parameters), but this 
obviously is not sufficient. I have tried to add it to the OF command 
above, and at the prompts that come later, all to no avail.

Thanks to anybody that could point out the correct solution.

Charles