Linux on Apple PowerMac

For simplicity, and because I have an 'Old World' Mac (Pre G4 and certain early G3s), I chose to implement a dual-OS setup, using a minimalist MacOS install to springboard into Linux with.
This required a fair amount of docs reading and thought before attempted, and after a few false starts (Mostly due to my not reading the docs well enough), managed to get a nicely working Debian Linux system setup.

I began with acquiring the software I needed, which included:

I was also armed with the PowerPC Debian installation manual.

I used HD SC to repartition the internal hard disk (Mine happened to be a 1.08G disk) giving MacOS a generous 28M partition, and leaving the remainder empty space.
(Actually, I used PLI Formatter Pro to go over the disk first and do a full badblocks check... but thats just a matter of circumstance, HDSC can do a low-level format)

I then installed a basic MacOS setup, which comprised of roughly 8 Megs of data.

After this I copied BootX, ramdisk.image.gz and root.bin from disks-powerpc/current/powermac off the mini-install CD.
I decompressed BootX onto the MacOS partition and moved the ramdisk image and kernel (root.bin) into BootXs "Linux Kernels" directory.
Next setup BootX to use the ramdisk.image.gz image to boot from, start Linux.

After you boot into Linux, the Debian installer dbootstrap will start.
The rest of the Debian installation tends to be a lot of hitting the enter key, however one point to note is the partitioning setup.
mac-fdisk shows the empty partition, unlike the usual 'fdisk' of not showing what isn't partitioned... (Technically the empty space is partitioned - its just labelled literally "Empty").
For more details on this, head here for a pretty comprehensive tutorial.

After getting Debian installed I had some issues getting BootX to like kernel images I was making, probably due to being unfamaliar with kernel builds for PPC.
My solution was to use pre-built kernels from the PowerPC Kernel Archives, particularly the Ben Herrenschmidt kernels (linux-benh-devel).
I found that with the kernel installs the keymap would all go to hell, and the trick to getting around this is to add a specific kernel parameter.
For detailed instructions head to TuxPPC's Kernel Install Instructions page, fills in a few gaps.

Thats about it...
Good places to head for help or general interest are: