Some Macs need extra help booting Linux. Here's the
how and why of booting Linux on different Macs.
I've received some emails (below) about this, so I
thought I would post a quick article to explain how and why Linux boots
on different type of Macs.
Unfortunately, "Old World" Macs cannot boot a Linux install
CD. Due to the way that Open Firmware 1.x & 2.x work, the Mac
must have the Classic Mac OS installed (not OS X). It only
needs to be a very basic installation that includes any extensions for
an installed processor upgrade's backside cache.
Once the Mac OS is running, the BootX program is used to reboot the
system into Linux. Whenever you shutdown Linux or reboot your Mac, the
Mac OS will start, and then you have to use BootX to start Linux once
again.
The "New World" boot loader, yaboot, doesn't yet have support for
Old World Macs. (Although this is in the works, it's not ready - and
unfortunately may never be ready. More on that when I get the
info.)
"Old World" Macs are any Macs with beige colored cases (and usually
PCI expansion slots). This includes all the pre-G3 PowerPC machines and
the PowerBook G3 "Kanga", the G3 Wallstreet Series I and
Series II, and the
original Beige G3s.
This doesn't include NuBus Power Macs, because while they have a
PowerPC processor, they don't have an Open Firmware BIOS. Support for
these machines is limited due to the lack of Open Firmware and lack of
drivers for some of the hardware.
The NetBSD Project has a
bootloader called "quik" that will boot an "Old World" Mac directly
without having the Mac OS installed. "quik" is also able to boot Linux.
However, it's not very easy to set up due to some issues with the way
Open Firmware was implemented on many of the "Old World" Macs. I'll
eventually cover installing NetBSD and will go over using "quik" at
that time.
"New World" Macs started with the colored iMacs and include all the
Power Macs since the Blue & White G3s
and the Lombard
PowerBooks. These machines are able to boot a Linux install CD
directly and are able to boot directly into Linux. They don't have to
have the Mac OS installed.
Most Linux distributions available for the PowerPC support the "New
World" Macs.
Intel Macs have limited support for Linux, but this is something
that will improve as the machines mature. Someone had Linux running on
the new MacBook Pros before Windows was up and running on
them.
Since Low End Mac is more about older Macs, I will probably not be
covering these machines (unless I end up getting one, which is unlikely
anytime soon).
The primary video card in you're Mac must have an Open
Firmware BIOS on it. However, once Linux has started, most PC-based PCI
cards will be recognized by Linux and can be usable even if they are
not usable with the Mac OS.
I apologize for not going over this sooner, and I hope that this
clears things up. I will be posting a list of which Linux Distributions
support which types of Macs and the major features of each distro
soon.
Linux on the Low End
Mailbag
Problem Booting Ubuntu LiveCD
From Dan Palka:
I tried using an Ubuntu LiveCD
for PowerPC on my G4-upgraded 8600,
but it just ignored it completely. My PowerBook G4 and iMac G3 booted
from the Ubuntu CD fine, though.
Any ideas?
REPLY
Hi Dan. The problem is that the "Old World" Macs cannot boot a Linux
CD. You'll have to get the BootX program from here:
http://penguinppc.org/historical/benh/BootX_1.2.2.sit
The program has to be run from Classic Mac OS. It will not
run from OS X.
You'll also have to copy the appropriate kernel and initrd files
onto the Mac OS hard drive. The yaboot boot loader that is used on the
"New World" Macs will not work on your 8600.
I have been in contact with someone who will hopefully be rewriting
yaboot to work with the "Old World" Macs, but this hasn't happened yet.
Further, there are some issues with the Open Firmware in those Macs,
which you can get more info on from the NetBSD Support
Page.
My next article will deal with how to obtain and install BootX and
how to get the Linus installer up and running. It will also go over how
(and why) to set up your hard drive for Linux. It should be up on
Wednesday. I'll be going over openSuSE v10.0,
but I'm planning to do a review/install of Ubuntu soon.
Toying with PPC Linux
From James Taylor:
Hello,
I just thought I'd drop a line to let you know how informative and
helpful your article is (and will be, as I see it's an ongoing set),
and I look forward to more information as you progress.
I have an aging G4/733 (well,
it's not that aging), and I have been toying with the idea for
quite some time of converting it to Linux. I still use OS X on my
main G5 machine (but in the future, even this machine might become
Linux as PPC becomes a memory in Apple's lineup). Your series is going
to be the impetus for me to give Linux a go on PPC. (I have used Linux
off and on in the PC realm since downloading the 30 or so floppy images
for Slackware 0.99 back in college. I never got X working, but it was a
great console-based connection to the school's Unix machines. We used
SLiRP to fake a connection to the HPUX boxes via modems.)
I flirted with Windows for a time, but I recently donated my last
Windows machine to a woman whose HP died. Now all my PCs are Linux
("sort of" servers), and my Macs are my primary computers. (I am a
software engineer by profession, so I tend to have an entirely too high
machine-to-person ratio.)
Anyway, thanks again for the article.
REPLY
Hi James. Thanx for the praise.
Right now I'm working on helping people install Linux onto the "Old
World" machines, because they require a little more work in order to
them to get them running properly. I'm going to cover the "New World"
machines soon.
It's easier to get Linux installed and running on them, but there
are still some other considerations for them compared to installing
Linux on a PC. Most Linux distributions offer more support for the "New
World" machines with Yellow Dog Linux being a
PowerPC only distro.
The only computers I run Windows on are really old machines with
very little RAM. 
