Boot different kernel with yaboot?

[ubuntubrian]

I have all of these kernel images in /boot and I wanted to try booting some of the older ones to see if they correct the issues I still have with Hardy on my TiBook G4,powerpc.
Is there a simple way? Do I need to edit yaboot.conf (I'm sure I do)and if so what do I put in there?
Would something like this work? (The first 2 images are what are in the conf file already and I didn't include the mac boot files.

image=/boot/vmlinux
label=Linux
read-only
initrd=/boot/initrd.img
append="quiet splash"

root = /dev/hda8
image=/boot/vmlinux.old
label=old
read-only
initrd=/boot/initrd.img.old
append="quiet splash"
root = /dev/hda8
image=/boot/vmlinux-2.6.15-52-powerpc
label=testkernel
read-only
initrd=/boot/initrd.img.old
append="quiet splash"
root = /dev/hda8


Thanks for any help!

[tiresia]

Do not change your yaboot.conf! You do not need.
Just hit TAB when yaboot starts, and you can choose the kernel you want to boot.

[ubuntubrian]

Thanks for the reply. I only have "Linux" and "old", which I have always had. I'd like to boot one of the other kernels in /boot. Here're the contents of /boot:

/boot$ ls
abi-2.6.12-9-powerpc initrd.img-2.6.15-51-powerpc
abi-2.6.15-20-powerpc initrd.img-2.6.15-52-powerpc
abi-2.6.15-21-powerpc initrd.img-2.6.24-19-powerpc
abi-2.6.15-22-powerpc initrd.img-2.6.24-19-powerpc.bak
abi-2.6.15-23-powerpc initrd.img-2.6.24-19-powerpc-smp
abi-2.6.15-26-powerpc initrd.img-2.6.24-19-powerpc-smp.bak
abi-2.6.15-27-powerpc initrd.img.old
abi-2.6.15-28-powerpc System.map-2.6.12-8-powerpc
abi-2.6.15-29-powerpc System.map-2.6.12-9-powerpc
abi-2.6.15-51-powerpc System.map-2.6.15-20-powerpc
abi-2.6.15-52-powerpc System.map-2.6.15-21-powerpc
abi-2.6.24-19-powerpc System.map-2.6.15-22-powerpc
abi-2.6.24-19-powerpc-smp System.map-2.6.15-23-powerpc
config-2.6.12-8-powerpc System.map-2.6.15-26-powerpc
config-2.6.12-9-powerpc System.map-2.6.15-27-powerpc
config-2.6.15-20-powerpc System.map-2.6.15-28-powerpc
config-2.6.15-21-powerpc System.map-2.6.15-29-powerpc
config-2.6.15-22-powerpc System.map-2.6.15-51-powerpc
config-2.6.15-23-powerpc System.map-2.6.15-52-powerpc
config-2.6.15-26-powerpc System.map-2.6.24-19-powerpc
config-2.6.15-27-powerpc System.map-2.6.24-19-powerpc-smp
config-2.6.15-28-powerpc vmlinux
config-2.6.15-29-powerpc vmlinux-2.6.12-8-powerpc
config-2.6.15-51-powerpc vmlinux-2.6.12-9-powerpc
config-2.6.15-52-powerpc vmlinux-2.6.15-20-powerpc
config-2.6.24-19-powerpc vmlinux-2.6.15-21-powerpc
config-2.6.24-19-powerpc-smp vmlinux-2.6.15-22-powerpc
initrd.img vmlinux-2.6.15-23-powerpc
initrd.img-2.6.12-8-powerpc vmlinux-2.6.15-26-powerpc
initrd.img-2.6.12-9-powerpc vmlinux-2.6.15-27-powerpc
initrd.img-2.6.15-20-powerpc vmlinux-2.6.15-28-powerpc
initrd.img-2.6.15-21-powerpc vmlinux-2.6.15-29-powerpc
initrd.img-2.6.15-22-powerpc vmlinux-2.6.15-51-powerpc
initrd.img-2.6.15-23-powerpc vmlinux-2.6.15-52-powerpc
initrd.img-2.6.15-26-powerpc vmlinux-2.6.24-19-powerpc
initrd.img-2.6.15-27-powerpc vmlinux-2.6.24-19-powerpc-smp
initrd.img-2.6.15-28-powerpc vmlinux.old
initrd.img-2.6.15-29-powerpc


Any help?

[tiresia]

Sorry, but I had not understood your question. If you compiled a new kernel and you want to try it, yes you should change your yaboot.conf in order to boot a different kernel. Once you are done, don't forget to runybin -v

[ubuntubrian]

Thanks for the quick reply Tiresia! I'm glad I cleared that up for you but....
These are old kernels that have been in /boot since Dapper and I've never removed them. there are a couple of things that I'm trying to accomplish.
the first is to see if I can boot one of the older kernels and if so the question is how do I modify my yaboot.conf file? I have read much on it but am still unsure which is why I included my hypothetical configuration in the first post which references a kernel image in /boot.
I have not compiled a new kernel but may try that as I have Mac-On-Linux installed which will not run with my current kernel 2.6.24-19, but people report will with a Gutsy kernel. Compiling that is a whole other matter that I have never even tried but I'm game.
So, to sum up, are these images in /bott actually bootable and if so just how do I edit my yaboot.conf file to use them?
BTW, I was following this which has good info but for a newbie there's too much ambiguity:http://www.linuxchix.org/content/courses/kernel_hacking/lesson4

Many, many thanks!

[tiresia]

First of all, make a backup of your yaboot.conf
sudo cp /etc/yaboot.conf /etc/yaboot.conf-backup

You need to specify in yaboot.conf following:

1. The filesystem path to the kernel image (image=)
2. The related ramdisk image for the kernel you want to load (initrd=)

Since it seems that you want to boot the kernel 'vmlinux-2.6.15-52-powerpc', make a symlink to that kernel with the name 'vmlinux.oldest' (or whatever you want) and a symlink to its ramdisk image with 'initrd.img.oldest' (or whatever you want):

sudo ln -s /boot/vmlinux-2.6.15-52-powerpc /boot/vmlinux.oldest
sudo ln -s /boot/initrd.img-2.6.15-52-powerpc /boot/initrd.img.oldest

Your yaboot.conf should look like this:

image=/boot/vmlinux
label=Linux
read-only
initrd=/boot/initrd.img
append="quiet splash"
root = /dev/hda8

image=/boot/vmlinux.old
label=old
read-only
initrd=/boot/initrd.img.old
append="quiet splash"
root = /dev/hda8

image=/boot/vmlinux.oldest
label=oldest
read-only
initrd=/boot/initrd.img.oldest
append="quiet splash"
root = /dev/hda8

Save the file and run ybin
sudo ybin -v

Restart your computer, at the boot: prompt, hit TAB. Now you should see the three kernels, that you can choose: Linux, old and oldest. Type 'oldest' (or the label you hace choosen to select the vmlinux-2.6.15-52-powerpc kernel).

---

P.S. I'm not sure, that your system will work, but you can try anyway…
I guess you know these links:
http://mac-on-linux.sourceforge.net/wiki/index.php/Main_Page
http://mac-on-linux.sourceforge.net/wiki/index.php/Installation_Instructions
https://help.ubuntu.com/community/MacOnLinuxHowto

[ubuntubrian]

Thanks so much for the clear instructions! this was on some of the wikis, etc. but the actual editing was unclear to me and you cleared it right up tiresia. I realize that the older kernels may not run with Hardy but I can also now install a Gutsy kernel and try that and yes, I am going for MOL as well as trying to get better performance as Hardy is much slower than Dapper was on my TiBook.
Interestingly, it is now suspending and waking fine and if I leave it booted and don't shut down the performance improves over time. Odd...

[ubuntubrian]

BTW, do you run MOL on Hardy tiresia?

[tiresia]

BTW, do you run MOL on Hardy tiresia?
No, unfortunatly I can't, because MOL doesn't run on powerpc64…
I can only use Qemu to emulate an OS, but it does not work with emulate a powerpc architecture (even if it says it does)

[ubuntubrian]

hi Sayad. Is part of your post missing? I don't understand it otherwise.
I have MOL installed and it ran great on Dapper but it will not on Hardy. Actually it's OS X drivers that can't be installed so i guess that OS 9 would run but I don't have that installed.
I have read that various kernel patches and building a kernel allow it to run on Hardy but the simplest is a post that stated that it would run of a Gutsy kernel. I'm not sure how that works yet and if I could just install the drivers once booted into a Gutsy kernel and run MOL or not.
Getting a Gutsy kernel to boot would be a first step.

[ubuntubrian]

Ah well, that didn't work! Installing the Gutsy kernel caused a requested restart, which I did. That created some major errors with the package manager and I had to uninstall the Gutsy kernel and Update Manager requested an update. I did the update, which were kernel updates and some odds and ends, and my sound died. I also lost the "old" yaboot option and by uninstalling the Gutsy kernel I'm left with a link to it from these commands:

Code:

sudo ln -s /boot/vmlinux-2.6.15-52-powerpc /boot/vmlinux.oldest

Code:

sudo ln -s /boot/initrd.img-2.6.15-52-powerpc /boot/initrd.img.oldest



and this is what remains:

lrwxrwxrwx 1 root root 35 2008-08-29 10:37 vmlinux.oldest -> /boot/vmlinux-2.6.22-15-powerpc-smp


I don't know why the link switched to the 22.15 kernel but that isn't installed anymore. I'd like to remove the link. I created another link to the 15.52 kernel named "Dapper".

Thanks for any help!

[ubuntubrian]

Scary! My yaboot.conf is in tough shape now. I installed an earlier kernel (yes, since last post) from Synaptic as I thought that that shouldn't be an issue. I cleaned up my /boot file by creating links to the older images using:
sudo cp /etc/yaboot.conf /etc/yaboot.conf-backup
then:
sudo ln -s /boot/vmlinux-2.6.15-52-powerpc /boot/vmlinux.dapper
sudo ln -s /boot/initrd.img-2.6.15-52-powerpc /boot/initrd.img.dapper
sudo ln -s /boot/initrd.img-2.6.24-18-powerpc-smp /boot/initrd.img.2.6.24-18-smp
sudo ln -s /boot/vmlinux-2.6.24-18-powerpc-smp /boot/vmlinux.2.6.24-18-smp

I edited my yaboot.conf and ran
sudo ybin -v


I had installed the image for 2.6.24-19-powermac-smp during the previous update and had fortunately added it to my yaboot.conf. After this I decided to give up rather than further bork my set up and so I uninstalled the 2.6.24-18 and 2.6.24-16 kernels, images and headers through Synaptic as I had used it to install them. Should be safe.
I did the uninstall thinking that I at least still had the vmlinux boot option as well as the 2.6.24-19-smp.
Here's my current yaboot.conf:
image=/boot/vmlinux
label=Linux
read-only
initrd=/boot/initrd.img
append="quiet splash"

root = /dev/hda8
image=/boot/vmlinux.old
label=old
read-only
initrd=/boot/initrd.img.old
append="quiet splash"
root = /dev/hda8

image=/boot/vmlinux-2.6.24-19-powerpc-smp
label=24.19-smp
read-only
initrd=/boot/initrd.img-2.6.24-19-powerpc-smp
append="quiet splash"
root = /dev/hda8


Upon rebooting I hit tab and had the options of "Linux", "Old" and "24.19-smp". Only the 24.19-smp would boot (in which I have no sound at all).
Here's my /boot file:
brianokeefe@ubuntu:/boot$ ls -l
total 203264
-rw-r--r-- 1 root root 208261 2005-10-10 08:47 abi-2.6.12-9-powerpc
-rw-r--r-- 1 root root 244963 2006-04-04 13:02 abi-2.6.15-20-powerpc
-rw-r--r-- 1 root root 245179 2006-04-21 11:09 abi-2.6.15-21-powerpc
-rw-r--r-- 1 root root 248384 2006-05-07 11:03 abi-2.6.15-22-powerpc
-rw-r--r-- 1 root root 248749 2006-05-23 08:10 abi-2.6.15-23-powerpc
-rw-r--r-- 1 root root 249098 2006-09-08 14:15 abi-2.6.15-26-powerpc
-rw-r--r-- 1 root root 249098 2006-12-08 11:13 abi-2.6.15-27-powerpc
-rw-r--r-- 1 root root 249098 2007-07-18 17:14 abi-2.6.15-28-powerpc
-rw-r--r-- 1 root root 249098 2007-09-24 11:41 abi-2.6.15-29-powerpc
-rw-r--r-- 1 root root 249098 2008-02-12 10:16 abi-2.6.15-51-powerpc
-rw-r--r-- 1 root root 249098 2008-07-11 07:44 abi-2.6.15-52-powerpc
-rw-r--r-- 1 root root 427444 2008-08-20 15:50 abi-2.6.24-19-powerpc
-rw-r--r-- 1 root root 430520 2008-08-20 15:52 abi-2.6.24-19-powerpc-smp
-rw-r--r-- 1 root root 46759 2005-08-30 16:01 config-2.6.12-8-powerpc
-rw-r--r-- 1 root root 46817 2005-10-10 08:25 config-2.6.12-9-powerpc
-rw-r--r-- 1 root root 57616 2006-04-04 11:44 config-2.6.15-20-powerpc
-rw-r--r-- 1 root root 57780 2006-04-21 10:44 config-2.6.15-21-powerpc
-rw-r--r-- 1 root root 57939 2006-05-07 09:44 config-2.6.15-22-powerpc
-rw-r--r-- 1 root root 57999 2006-05-23 07:45 config-2.6.15-23-powerpc
-rw-r--r-- 1 root root 58003 2006-09-08 13:50 config-2.6.15-26-powerpc
-rw-r--r-- 1 root root 57992 2006-12-08 10:50 config-2.6.15-27-powerpc
-rw-r--r-- 1 root root 57992 2007-07-18 16:49 config-2.6.15-28-powerpc
-rw-r--r-- 1 root root 57992 2007-09-24 11:18 config-2.6.15-29-powerpc
-rw-r--r-- 1 root root 57992 2008-02-12 09:53 config-2.6.15-51-powerpc
-rw-r--r-- 1 root root 57992 2008-07-11 07:21 config-2.6.15-52-powerpc
-rw-r--r-- 1 root root 72382 2008-08-20 15:50 config-2.6.24-19-powerpc
-rw-r--r-- 1 root root 72101 2008-08-20 15:52 config-2.6.24-19-powerpc-smp
-rw-r--r-- 1 root root 5871736 2005-09-15 20:33 initrd.img-2.6.12-8-powerpc
-rw-r--r-- 1 root root 7314502 2006-04-25 13:02 initrd.img-2.6.12-9-powerpc
-rw-r--r-- 1 root root 7799808 2006-04-28 00:09 initrd.img-2.6.15-20-powerpc
-rw-r--r-- 1 root root 7802526 2006-05-05 22:42 initrd.img-2.6.15-21-powerpc
-rw-r--r-- 1 root root 8072411 2006-05-26 07:38 initrd.img-2.6.15-22-powerpc
-rw-r--r-- 1 root root 8072698 2006-05-29 16:07 initrd.img-2.6.15-23-powerpc
-rw-r--r-- 1 root root 8091421 2006-09-15 00:00 initrd.img-2.6.15-26-powerpc
-rw-r--r-- 1 root root 8091066 2006-12-14 11:11 initrd.img-2.6.15-27-powerpc
-rw-r--r-- 1 root root 8092300 2007-10-28 15:38 initrd.img-2.6.15-28-powerpc
-rw-r--r-- 1 root root 8145517 2007-12-17 11:54 initrd.img-2.6.15-29-powerpc
-rw-r--r-- 1 root root 8146270 2008-02-15 16:10 initrd.img-2.6.15-51-powerpc
-rw-r--r-- 1 root root 8146256 2008-07-15 16:22 initrd.img-2.6.15-52-powerpc
lrwxrwxrwx 1 root root 38 2008-08-30 22:30 initrd.img.2.6.24-18-smp -> /boot/initrd.img-2.6.24-18-powerpc-smp
-rw-r--r-- 1 root root 9618353 2008-08-29 14:11 initrd.img-2.6.24-19-powerpc
-rw-r--r-- 1 root root 9480443 2008-08-08 14:09 initrd.img-2.6.24-19-powerpc.bak
-rw-r--r-- 1 root root 9694652 2008-08-29 14:12 initrd.img-2.6.24-19-powerpc-smp
-rw-r--r-- 1 root root 9694448 2008-08-17 14:04 initrd.img-2.6.24-19-powerpc-smp.bak
lrwxrwxrwx 1 root root 34 2008-08-30 22:28 initrd.img.Dapper -> /boot/initrd.img-2.6.15-52-powerpc
lrwxrwxrwx 1 root root 38 2008-08-29 10:38 initrd.img.oldest -> /boot/initrd.img-2.6.22-15-powerpc-smp
-rw-r--r-- 1 root root 822631 2005-08-30 17:09 System.map-2.6.12-8-powerpc
-rw-r--r-- 1 root root 822587 2005-10-10 08:47 System.map-2.6.12-9-powerpc
-rw-r--r-- 1 root root 667637 2006-04-04 13:03 System.map-2.6.15-20-powerpc
-rw-r--r-- 1 root root 667637 2006-04-21 11:09 System.map-2.6.15-21-powerpc
-rw-r--r-- 1 root root 667637 2006-05-07 11:03 System.map-2.6.15-22-powerpc
-rw-r--r-- 1 root root 667985 2006-05-23 08:10 System.map-2.6.15-23-powerpc
-rw-r--r-- 1 root root 660829 2006-09-08 14:16 System.map-2.6.15-26-powerpc
-rw-r--r-- 1 root root 660335 2006-12-08 11:13 System.map-2.6.15-27-powerpc
-rw-r--r-- 1 root root 661511 2007-07-18 17:14 System.map-2.6.15-28-powerpc
-rw-r--r-- 1 root root 661564 2007-09-24 11:42 System.map-2.6.15-29-powerpc
-rw-r--r-- 1 root root 661564 2008-02-12 10:16 System.map-2.6.15-51-powerpc
-rw-r--r-- 1 root root 661564 2008-07-11 07:44 System.map-2.6.15-52-powerpc
-rw-r--r-- 1 root root 839034 2008-08-20 15:50 System.map-2.6.24-19-powerpc
-rw-r--r-- 1 root root 859699 2008-08-20 15:52 System.map-2.6.24-19-powerpc-smp
-rw-r--r-- 1 root root 4134082 2005-08-30 17:09 vmlinux-2.6.12-8-powerpc
-rw-r--r-- 1 root root 4134050 2005-10-10 08:47 vmlinux-2.6.12-9-powerpc
-rw-r--r-- 1 root root 4258251 2006-04-04 13:02 vmlinux-2.6.15-20-powerpc
-rw-r--r-- 1 root root 4258176 2006-04-21 11:09 vmlinux-2.6.15-21-powerpc
-rw-r--r-- 1 root root 4258176 2006-05-07 11:03 vmlinux-2.6.15-22-powerpc
-rw-r--r-- 1 root root 4262734 2006-05-23 08:10 vmlinux-2.6.15-23-powerpc
-rw-r--r-- 1 root root 4208331 2006-09-08 14:15 vmlinux-2.6.15-26-powerpc
-rw-r--r-- 1 root root 4207807 2006-12-08 11:13 vmlinux-2.6.15-27-powerpc
-rw-r--r-- 1 root root 4209188 2007-07-18 17:14 vmlinux-2.6.15-28-powerpc
-rw-r--r-- 1 root root 4209237 2007-09-24 11:41 vmlinux-2.6.15-29-powerpc
-rw-r--r-- 1 root root 4209237 2008-02-12 10:16 vmlinux-2.6.15-51-powerpc
-rw-r--r-- 1 root root 4209233 2008-07-11 07:44 vmlinux-2.6.15-52-powerpc
lrwxrwxrwx 1 root root 35 2008-08-30 22:31 vmlinux.2.6.24-18-smp -> /boot/vmlinux-2.6.24-18-powerpc-smp
-rw-r--r-- 1 root root 5137620 2008-08-20 15:50 vmlinux-2.6.24-19-powerpc
-rw-r--r-- 1 root root 5355247 2008-08-20 15:52 vmlinux-2.6.24-19-powerpc-smp
lrwxrwxrwx 1 root root 31 2008-08-30 22:27 vmlinux.Dapper -> /boot/vmlinux-2.6.15-52-powerpc
lrwxrwxrwx 1 root root 35 2008-08-29 10:37 vmlinux.oldest -> /boot/vmlinux-2.6.22-15-powerpc-smp


I hadn't made a link for the 2.6.24-19-powermac-smp image, just added it to my yaboot.conf as you see above. Luckily it booted.
The question is why did "Linux" disappear from /boot and no longer be a boot option? How do I get it back? How do I clean up /boot to something functional (moreso at least).
thanks for any help!