Booting a PowerBook from a LiveCD image on an USB-Stick

I have an old Apple PowerBook G4 with a broken CD/DVD drive. For most practical purposes, the broken drive is no issue. However, if you’re going to re-install the laptop, it becomes one. Luckily, the PowerBook is able to boot from USB…

At first, I tried following the instructions on "LiveUSB on PPC" found in Gentoo’s Wiki, but that didn’t work out at first. I then found a blog entry titled "Creating a bootable USB Stick with Mac OS X in 10 easy steps&quot. Combining the two lead to success, so here’s what I did:

  • I downloaded the latest PowerPC release of Finnix, a &quot self-contained, bootable Linux CD distribution&quot from the project’s front page.

  • I re-named the ISO image from finnix-ppc-105.iso to finnix-ppc-105.dmg. Also, I displayed the file’s information in Finder by right-clicking on the file icon and selecting "Show Information&quot. I doubt that this step is required but it certainly didn’t do any harm.

  • From a shell, aka "Terminal Window&quot, I used the command diskutil list to find the device path to my USB drive. In my case, it was /dev/disk6.

  • I then unmounted the drive by running

    $ diskutil unmountDisk /dev/disk6

  • Using good, old dd(1), I wrote the disk image to the USB drive:

    $ sudo dd if=finnix-ppc-105.dmg of=/dev/disk6 bs=1m
  • Finnally, I unmounted the drive by running:

    $ diskutil eject /dev/disk6

In order to boot the PowerBook from the USB drive, I had to drop into Open Firmware. In case you didn’t know it, this is done by holding down Cmd+Option+o+f right after the computer is turned on.

The next step was to find the device node of the bootable USB drive. To do this, I browsed the device tree for any USB node that had a disk child node.

> dev /
> ls

In my case, the USB drive was at /pci@f2000000/usb@1b,1/disk@1.

The instruction found on the Gentoo wiki assign the cd alias to that node, so I did that, too, by running:

> devalias cd /pci@f2000000/usb@1b,1/disk@1

This allowed me to finally boot from the USB drive like this:

> boot cd:,\:tbxi