Linux on a colorful iMac

My fiance’s parents have an older iMac — one of the colorful CRT ones. We are trying to install Linux on it.
Here are some more details about the particular machine from The Debian PowerPC installer page suggests that our iMac is a “new world” PowerPC iMac, and that Debian should install just fine. Now, this particular system runs at 333 MHz and has only 32 MB of RAM, i.e., not much. I crossed my fingers and inserted the installer CD, and powered on the iMac while holding down the ‘c’ key to boot from CD. The ‘yaboot’ prompt greeted me, it loaded the kernel, and then tried to load the initial ram disk. At that point the screen’s background changed from black to white and the system dropped to an Apple firmware prompt (pretty cool actually, that’s never happened to me with a PC). The following error message appeared:

Error: Can’t allocate initial device-tree chunk
This Ubuntu forum post suggests that numerous people have seen this issue, and that it can be resolved by installing the “Alternate” version of Xubuntu 6.06.1. Unfortunately, this didn’t solve my problem. It seems that 32 MB is just not enough RAM for these stock distributions. Here is another thread about somebody else who had the same problem.

I decided to try an older version of Debian, and it worked! I successfully installed Debian Sarge for PPC from the netinst CD.

I had some problems formatting the hard drive during the install. Specifically, formatting worked fine, but the resulting partitions couldn’t be mounted. I believe this to have been a problem with the necessary kernel modules not being available. These modules were unavailable because, on a system with so little RAM (32 MB), the Debian installer doesn’t automatically load all components. I experimented with different combinations of what appeared to be the right installer components (sorry, I didn’t keep more careful records), rebooting several times. In the end I used the ‘partman’ automatic partitioning module to setup the partitions, and it just worked. 🙂

I also had to enable specific installer components to get the ‘bmac’ ethernet driver to work. Once those were enabled, the network configured successfully using DHCP.

The installer booted with a v2.4 kernel. At the end of the install, it wanted to install a v2.6 kernel. I nervously accepted, and the resulting system booted perfectly during the first reboot without the CD. Cool!

I was able to get X working using `aptitude install x-window-system`, accepting all the defaults, and then adding one line to the “Device” section of my XF86Config-4:
BusID “PCI:0:18:0”
I got the hint for that line from this page, and the actual numbers from `cat /proc/pci`.

I installed the xfce window manager, and Mozilla Firefox. Both worked. We’re up and running. 🙂

The system ran out of memory trying to compile scilab from source, but I killed the X server and did the compile from a tty. It worked. 🙂


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