Linux on iMac 8,1

Introduction

This is intended to be an installation guide for Intel iMac users with alot of information pulled from Ubuntu Help. At this time, this is for the 64bit major variations of the Intel iMac, that don’t have the T2 chip.

Older information is available in these pages: https://wiki.ubuntu.com/iMacIntel https://help.ubuntu.com/community/iMacCoreDuo

Basic instructions

Here I present my preferred method of installation

  1. Get your Ubuntu Live CD or USB flash drive ready. The Live CD should work, but if you have trouble, try the Alternate Install CD. If you have a Core2 Duo Mac (as oppossed to the Core Duo), it is capable of using the AMD64 (64bit) CD otherwise you have to use the standard version.
  2. It is highly recommended that you install rEFIt. rEFIt is a user friendly interface to the Mac EFI that will cause a boot menu (to select between OS X/Ubuntu) to appear on every boot. You can make Ubuntu boot by default by uncommenting the ‘legacyfirst’ option and change the menu timeout in the “refit.conf” file (described on the above website).
  3. At this point you need to make room for Ubuntu by shrinking the OS X partition. This can be done with various tools:
    • In OS X Leopard (10.5.x), the Disk Utility is able to ‘add’ a partition to the durrent disk without completely repartitioning the hard drive. To use this method, start Disk Utility, (Applications > Utilities) Select the Hard drive to partition, and click the ‘+’ button to add a partition. You can then resize the partition to suit the amount of space you would like to use for Ubuntu. Don’t worry about the partition format (Mac OSX, UFS, etc), we will be reformatting the partition later.
    • gParted can shrink your OS X partition as well, but it is not able to “grow” or increase the size of a partition once it have been resized.
  4. Hold down “C” to boot from the CD or the Option key to boot from a usb. The USB should be listed as “efi boot”
  5. You should get a boot menu to select the type of boot you would like. Choose to start Ubuntu (NOTE: you can start the LiveCD, or you can choose to start the installer, choose to start the live environment).
  6. Once you get to the desktop, start gParted: System > Administration > Partition Editor
    • It should be plainly visible that there is an EFI partition at the beginning of the disk, followed by the HFS+ (OS X) partition, and lastly, the new partition you created.
    • Select the last partition and delete it. Make sure to click the Apply button to actually remove the partition. This will leave you with free space to install to. Exit gParted.
    • Once back to the desktop, double-click in the install icon to start the installer. When prompted, choose to install to the “largest, continuous free space”. This will allow the installer to create a root and swap partition for you. If you would like to have more control over the partitioning, you can choose to “manually partition”.

I personally had the best installation method buy using a large partition mounted to “/” or root, and about 4-8GB as a smaller partion for swap. The installer did ask where to place the bootloader, and I had the bootloader placed in “/”. Your experience may vary, so make sure you check the Ubuntu forums for help on a problem not outlined in this guide.

Due to a bug in the installer, you will likely not be able to boot into your installed system after the installation has finished. This can be corrected by completing the steps at the following post: http://ubuntuforums.org/showthread.php?t=767677. Its more in depth, and has you run rEFIt, or manually installing the grub file. I didn’t have these issues, but I am only dual booting, so again, make sure to read all documentation you can.

If you Dual-Boot or Triple-Boot:

  1. If you haven’t already, boot into OSX and install rEFIt. If you do not get the rEFIt menu when starting up your Mac, you may need to run a command in the OSX terminal to get it to work. See the manual install instructions.
  2. Once you reboot into the rEFIt menu, choose to start the partition tool. It will ask if you want to sync your partitions. Say yes. after rebooting, you should be able to select the Linux icon in rEFIt and it will boot into your Ubuntu install.

Fix Non-Functioning Hardware

WiFi / Airport

Broadcom released a driver for these cards that will be available in Intrepid 8.10. It is still available in proprietary drivers in Bionic Beaver 18.04 http://ubuntuforums.org/showthread.php?t=914697

Graphics / Video

Check 3D acceleration

To make sure your graphics are working properly, we need to make sure that 3D acceleration is working. You can check this with the command:
glxinfo |grep direct
You should see in the output “direct rendering: yes”

Intel Graphics

For iMac users with Intel graphics (some early white Intel iMacs), everything should be working out-of-the-box. If you have have any problems, be sure that your xorg.conf is set to use the ‘intel’ driver rather than the any of the other specialized Intel drivers like ‘i810’.

nVidia Graphics

For nVidia graphics, the 2D open-source driver gives you basic support out-of-the-box. If you want to run 3D applications, select System > Hardware Drivers > nVidia accellerated graphics driver (version 185) as recommended. This provides OpenGL support for Compiz.

ATI Graphics

For ATI graphics, you will need to install the proprietary graphics drivers. This can be done with the Driver Manger in System > Adminstration > Driver Manager. When installed correctly, reboot, and an additional check is to run
fglrxinfo
The output should tell you that the provider is ATI and not MESA.

I have the ATI Radeon 2400XT in my iMac, and it installed the graphic drivers automatically, but again your experiences may vary.

If you have issues with the driver in the Ubuntu repos, you can alternately try Envy or even download the driver from ATI’s website and install manually.

Sound

If you have an aluminum iMac and you do not have sound :
open /etc/modprobe.d/options.conf :
sudo nano /etc/modprobe.d/options.conf
and add “options snd-hda-intel model=imac24” or “options snd-hda-intel model=imac20” to the file and save ( ctrl+o and ctrl+x to exit )
then reboot.

Will Tinsdeall (Ubuntu 10.10 – Clean install, 27″ iMac Intel i7): Just open a terminal to run ‘alsamixer’ from the command-line. Ensure “Front speaker” is turned up and unmuted, using arrow keys and ‘M’ for mute toggle. (Best to open up Rhythmbox and play some music while doing this, changes are instant)

Eläimen.Varmuus: With Ubuntu 8.10 (amd 64) and iMac rev. early 2008 the first step was enough. I edited only /etc/modprobe.d/options.

Some of the Aluminum iMacs need a patch to get functioning sound. An ubuntuforums user, ‘nicfagn’ has created many patches and posted them in the forums. Many of the fixes have made it into the latest ALSA driver, so downloading and compiling the latest ALSA source code may work as well. Here is a link to a patch that many have found useful.

Tiziano Faion: If you have an Aluminium Imac setting in /etc/modprobe.d/alsa-base the option model=mbp3 make sound work without patching anything.

Klaus Doblmann: If your microphone doesn’t work (no mic-boost switch), set the model to “mbp3” instead of “imac24”.

Jonas Westerlund: If you only get sound from the internal speakers, “options snd-hda-intel model=mbp3″ fixes that at least on the 2008 24” aluminum model.

Matthew Fernandez: For a 2010 iMac you shouldn’t need to patch anything. Append “options snd-hda-intel model=mbp55” to /etc/modprobe.d/alsa-base.conf. Restart. Then enter alsamixer in a terminal window and unmute the Front Speaker channel (left and right arrows to switch channels, up and down to change volume, M to mute and unmute).

Gary Watts: For my 2009 24″ iMac, adding “options snd-hda-intel model=lenovo-sky” to /etc/modprobe.d/imac.conf (or indeed anything.conf) got sound working. Special thanks to zacbarton for his advice at http://ubuntuforums.org/showthread.php?t=1443020

Warren Harrison: For those unhappy with the audio quality (compared to OS X), install the Pulse Audio Equalizer (http://exploreubuntu.wordpress.com/2010/04/18/equalizer-for-pulse-audio/) and choose the “laptop” EQ preset. This significantly reduces the mid-range frequencies and brings the audio into closer parity with OS X-native quality.

iMac 27″ & ubuntu 11.04

Since kernel 2.6.38, the HD audio model imac27 is available.

The following line must be inserted at the end of the file /etc/modprobe.d/alsa-base.conf

  • options snd-hda-intel model=imac27

force reload alsa configuration

  • sudo alsa force-reload

then unmute and adjust volume of front speaker and Surround Speaker with the help of :

  • alsamixer

Seen at http://ubuntuforums.org/showthread.php?t=1043568 and http://www.mjmwired.net/kernel/Documentation/sound/alsa/HD-Audio-Models.txt

iSight

https://help.ubuntu.com/community/AppleiSight

This shouldn’t be required, as the iSight drivers are in the kernel with newer releases of Ubuntu.

Aluminium keyboard

Users are reporting problems with the aluminium keyboard. The keyboard is still partially functional so long as the keypad on the right is not used. If you have problems with the main keyboard try pressing F6 to turn off num-lock. PLEASE add your comment to the launchpad bug tracker.

Magic Mouse

https://help.ubuntu.com/community/AppleMagicMouse

Extras

Compiz

Compiz (Desktop Effects) can be enabled after enabling 3D acceleration by installing the appropriate graphics drivers as shown above.