Is Ubuntu giving up on the PPC platform?

[Larry Grover]

Brian Durant wrote:
> On 12. feb 2006, at 19.56, Larry Grover wrote:
> 
>> Brian Durant wrote:
>>> Hi Larry,
>>> Nice to hear from you again. I have the yaboot.conf issue solved, 
>>> Here was the solution for that:
>>> ofpath /dev/sda
>>> /ht at 0,f2000000/pci at 3/k2-sata-root at c/k2-sata at 0/disk at 0:
>>> ofpath /dev/sdb
>>> /k2-sata at 0/disk at 0:
>>> sudo mv /usr/sbin/ofpath /usr/sbin/ofpath.orig
>>> cd /usr/sbin
>>> sudo wget -P . http://people.redhat.com/pnasrat/ofpath
>>> chmod 755 ofpath
>>
>>
>> Ah, so the problem was with the ofpath binary distributed by Ubuntu? 
>> Hopefully Dapper gets a less buggy version.  Did you file this bug on 
>> Malone, along with your solution?
> 
> The way I understood it, there was a bug in the version of yaboot that 
> was included. I haven't done anything as I wasn't sure if that qualified 
> as an Ubuntu bug or not. I just follow the instructions that I get when 
> there is some one that is kind enough to help me and then I learn by 


If it's in an Ubuntu package, then it's an Ubuntu bug.  Getting your bug 
into the bug tracking database is a good way to make sure it is brought 
to the attention of the Ubuntu developers, so it stands a chance of 
getting fixed.


>>> sudo ofpath /dev/sda
>>> /ht at 0,f2000000/pci at 3/k2-sata-root at c/k2-sata at 0/disk at 0:
>>> sudo ofpath /dev/sdb
>>> /ht at 0,f2000000/pci at 3/k2-sata-root at c/k2-sata at 1/disk at 0:
>>> sudo ybin -v
>>> Unfortunately, I haven't figured out how to get yaboot to boot 
>>> default into OS X yet. I tried "default=macosx", but no luck.
>>
>>
>> You might check the yaboot manpage and see if it is possible to use an 
>> open firmware path in the "default=..." line.  The "default" option 
>> may work if you can specify an of path rather than use the shorthand 
>> "macosx".


I don't at the moment have a linux-powerpc system available, and I don't 
remember the in's and out's of yaboot/ybin well enough to know if this 
is possible, but I was wondering if you can use something like this for 
the "default" option:

default=/ht at 0,f2000000/pci at 3/k2-sata-root at c/k2-sata at 1/disk at 0:

In other words, use the output of the ofpath command for your OSX drive 
as the target for "default".


> I know that there is something like using aliases to point to a SATA 
> drive (sd1), etc., but the other you are talking about, I have no idea.
> 
>>> With regards to the kernel issue, I see two possibilities as I 
>>> believe we have talked about before:
>>> 1) The patch that you are talking about. I don't know what the patch 
>>> would be called. Maybe something with windfarm_9.1.
>>
>>
>> I'm not sure either, but I image someone on the debian-powerpc list 
>> can point you to the correct patch.
> 
> They seem to be above dealing with newbies, which I can understand to a 
> certain extent. I try to look at those man pages and stuff, but I just 
> don't understand much and can't put the info it in a context.
> 
>>> 2) Installing the latest build of the stable (2.6) using 
>>> pmac_defconfig, i.e. latest build 2.6.15.4. This can be found at:
>>> http://www.ppckernel.org/kernel.php?id=74
>>> Unfortunately, as a newbie to Linux, I don't have the overview to 
>>> really know which is the easiest and simplest way to do this. What do 
>>> you suggest?
>>
>>
>> Installing a precompiled binary kerenel is bound to be easier and 
>> quicker (if it works).  The installation instructions are straight 
>> forward, so you might as well give it a try:
>> http://www.ppckernel.org/installation.php
>>
>> Just make sure that you leave an old, working kernel installed and 
>> leave a stanza for it in your yaboot.conf file, so that you can boot 
>> into the old kernel in case the 2.6.15.4. kernel from ppckernel.org 
>> doesn't work.   I assume you are familiar enough with the yaboot.conf 
>> file by now to figure this out?
> 
> Without screwing it up, you mean? ;-) I'm not sure...


As long as you don't erase any of your old kernel files (in /boot) or 
kernel modules (in /lib/modules), and as long as you leave the lines 
that refer to the existing kernel intact in your yaboot.conf file, you 
will be fine.

If you follow the install instructions on the ppckernel.org site, you 
should be fine.  Extracting and installing the files inside the 
linux-official-stable-pmac-2.6.15.4.tar.bz2 archive should not overwrite 
anything already on your system (at least not any files from Ubuntu 
packages).

When you edit your yaboot.conf file, make sure you don't erase or change 
any existing lines.  Simply copy the lines from a stanza which refers to 
an existing kernel, paste them, and edit them so they point to the files 
  from the 2.6.15.4 kernel.

You may need to make an initial RAM filesystem for the 2.6.15.4 kernel. 
  The following command should do it:

sudo mkinitramfs -o /boot/initrd.img-2.6.15.4 2.6.15.4


>> But I also suggest that you try patching and compiling your own 
>> kernel.   It's a good skill to know.  It is a bit involved, and it 
>> does takes some time, but it you have a good how-to or guide to 
>> follow, it is not really very hard.
>>
>> Regards,
>> Larry
> 
> Easy for you to say :-) I think I'll have to try and do some reading 
> before I try this. The problem is that I only have a certain amount of 
> time to get something like this to work, as I am otherwise afraid that 
> the computer pulls a China Syndrome on me. I don't have the luxury to 
> take the time to learn all of the fiddly bits.


As long as you don't do anything that erases or overwrites existing 
files for a working kernel (and damages your yaboot.conf file) you can't 
do any harm to your system.  To be on the safe side, you can backup the 
important bits before you start (burn them off to a CDR, etc):

/etc/yaboot.conf
/boot/System.map-2.6.*
/boot/vmlinux-2.6.*
/boot/initrd-2.6.*
/lib/modulues/*


Regards,
Larry