Making your Choice
Now that your kernel is configured and compiled and the necessary system
configuration files are filled in correctly, it is time to install a
program that will fire up your kernel when you start the system. Such a
program is called a bootloader.
On Linux/PPC64 we have only yaBoot as a bootloader until grub2 is
For a 64bit userland use yaboot-static instead of yaboot, because yaboot won't
compile on 64bit userland systems. For a 32bit userland use yaboot as you
There are two ways to configure yaBoot for your system. You can use the new and
improved yabootconfig included with yaboot-1.3.8-r1 and
later to automatically set up yaboot. If for some reason you do not want to run
yabootconfig to automatically set up /etc/yaboot.conf or you
are installing Gentoo on a G5 (on which yabootconfig does not always
work), you can just edit the sample file already installed on your system.
Code Listing 1.1: Installing Necessary File System Tools
# emerge hfsutils hfsplusutils
Code Listing 1.1: Installing the bootloader
# emerge --update yaboot-static
# emerge --update yaboot
yabootconfig/ybin won't work on IBM. You have to install yaboot another way:
Using yaboot on IBM hardware
If your root filesystem uses the JFS filesystem, be sure to add ro as a
kernel parameter. JFS must be able to replay its log in read-only mode before it
gets mounted read-write.
Default: Using yabootconfig
yabootconfig will auto-detect the partitions on your machine and will
set up dual and triple boot combinations with Linux, Mac OS, and Mac OS
To use yabootconfig, your drive must have a bootstrap partition, and
/etc/fstab must be configured with your Linux partitions. Both of
these should have been done already in the steps above. To start, ensure that
you have the latest version of yaboot installed by running emerge --update
yaboot-static. This is necessary as the latest version will be available via
Portage, but it may not have made it into the stage files.
Now run yabootconfig. The program will run and it will confirm the
location of the bootstrap partition. Type Y if it is correct. If not,
double check /etc/fstab. yabootconfig will then scan your system
setup, create /etc/yaboot.conf and run mkofboot for you.
mkofboot is used to format the bootstrap partition, and install the
yaboot configuration file into it.
You might want to verify the contents of /etc/yaboot.conf. If
you make changes to /etc/yaboot.conf (like setting the
default/boot OS), make sure to rerun ybin -v to apply changes to the
Now continue with Rebooting your System.
Alternative: Manual yaBoot Configuration
Below you find a completed yaboot.conf file. Alter it at
Code Listing 1.1: /etc/yaboot.conf
Once yaboot.conf is set up the way you want it, you run mkofboot
-v to install the settings in the bootstrap partition. Don't forget
this! Confirm when mkofboot asks you to create a new filesystem.
If all goes well, and you have the same options as the sample above, your next
reboot will give you a simple, five-entry boot menu. If you update your yaboot
config later on, you'll just need to run ybin -v to update the bootstrap
partition - mkofboot is for initial setup only.
For more information on yaboot, take a look at the yaboot project. For now,
continue the installation with Rebooting your System.
Using yaboot on IBM hardware
On IBM hardware you cannot run yabootconfig or ybin. You must proceed with the
- Install yaboot-static
Run dd if=/usr/lib/yaboot/yaboot.chrp of=/dev/sdXX (fill in XX with
your disk and partition for the PReP partition; this was in our example
Next construct your own yaboot.conf file and place into
/etc. (Take a look at the config above, look into the man page
of yaboot.conf or look at the below yaboot.conf
Assuming your boot device in OF is pointing to the harddrive you prep boot
partition is on then it'll just work, otherwise at IPL time, go into the
multiboot menu and set the boot device to the one with your prep boot
- That's it!
Code Listing 1.1: yaboot.conf for IBM hardware
For POWER4, POWER5, and blade-based hardware where the PReP disk partition and
the disk partition that contains your kernel are on the same physical disk, you
can use a simplified yaboot.conf. The following should be
Code Listing 1.1: yaboot.conf for PReP hardware
default = linux
timeout = 100
root = /dev/sda2
To verify that yaboot has been copied to the PReP partition:
Code Listing 1.1: Verifying the yaboot install on PReP
# dd if=/dev/sda1 count=10 | grep ELF
Binary file (standard input) matches
10+0 records in
10+0 records out
A match signifies that yaboot was installed correctly.
Rebooting the System
Exit the chrooted environment and unmount all mounted partitions. Then type in
that one magical command you have been waiting for: reboot.
Code Listing 1.1: Exiting the chroot, unmounting all partitions and rebooting
~# umount /mnt/gentoo/boot /mnt/gentoo/dev /mnt/gentoo/proc /mnt/gentoo
Of course, don't forget to remove the bootable CD, otherwise the CD will be
booted again instead of your new Gentoo system.
Once rebooted in your Gentoo installation, finish up with (Finalizing your Gentoo Installation).