I have a vintage 20" iMac 5,1 (64-bit Core2Duo / 32-bit EFI) from 2006. These first generation Intel iMacs were absolutely lovely, and have the following specs:
- 2.16 GHz Intel Core 2 Duo 64-bit processor
- 3GB DDR2 SDRAM
- 1680x1050 TFT Display
- Radeon Mobility X1600 accelerated graphics with 128MB GDDR3 RAM
- Built-in Ethernet and 802.11 wireless
- Looks super cool
This used to be a capable deskotp, but it's been a decade since Apple discontinued OS updates, rendering it mostly unusable in 2022. I wanted to keep this iMac from the landfill, so I restored it, replacing the hard drive with an SSD and installing modern 64-bit Linux.
There a few things about this machine that make installing Linux difficult, but I've been able to get everything working. Here's an overview of all the issues I came across.
The iMac 5,1 processor is a 64-bit Core2Duo and will run a 64-bit OS, however Macs of this generation (circa 2006 to 2007 or so) have a bizarre 32-bit EFI and consequently only support 32-bit EFI bootloader images.
The iMac's UEFI software also supports a legacy boot mode that presents a BIOS to the OS. I think this was originally intended for running Windows on the iMac in 2006. This happens to be particularly useful for Linux users in 2022!
The (ancient and unsupported) legacy driver for the Radeon video card does not work properly when booted from EFI on modern kernel versions, requiring the "nomodeset" kernel parameter. This not only disables video acceleration but causes the card to run without power management (hot!), and even breaks sleep functionality. It also makes desktop UI and video playback absurdly slow.
I could be mistaken, but I'm almost positive that many years ago, perhaps around 2015 with a much older kernel, I had hardware video acceleration working in EFI mode on this machine. This is no longer the case in 2022. I have tried getting the legacy Radeon driver to work under EFI boot on both 64-bit and 32-bit kernels and have been unsuccessful. I've pored over countless forums, tried numerous hacks, and have come to the conclusion that this is an unsolved issue. If you want to boot a 2006-07 iMac from EFI, you will have to disable video acceleration using the nomodeset kernel parameter or you will have to track down and fix an ancient bug in the legacy radeon driver in the Linux kernel.
BUT!
If you want video acceleration, sleep/suspend, and power throttling to work properly on the iMac5,1 with 64-bit Linux, there is at lest one way that works: boot in legacy BIOS mode with Grub in the MBR. The legacy Radeon firmware properly identifies the device and with a few configuration settings everything appears to work quite well.
| Boot Method | OS | Radeon driver |
|---|---|---|
| EFI (rEFInd 32) | Linux (32 bit) | unaccelerated (nomodeset) |
| EFI (rEFInd 32) | Linux (64 bit) | unaccelerated (nomodeset) |
| EFI (Grub EFI 32) | Linux (32 bit) | unaccelerated (nomodeset) |
| EFI (Grub EFI 32) | Linux (64 bit) | unaccelerated (nomodeset) |
| Legacy (Grub in MBR) | Linux (64 bit) | works! |
| Legacy (Grub in MBR) | Linux (32 bit) | works! (presumed, untested) |
Another quirk with the iMac 5,1 is that it only supports a maximum of 3GB ram, using two 2GB modules (yes, you read that correctly). 32-bit applications use a bit less RAM than their 64-bit counterparts, so an argument could be made to stick with 32-bit Linux. One issue, however, is that official package support for 32-bit systems is dwindling. Chromium, for example, ended official 32-bit builds in 2020.
Despite being a bit more memory hungry, it seems 64-bit Linux is the best option in 2022.
Don't bother. There was a reasonable argument for this in 2012, but there's no benefit to running MacOS Lion in 2022. Even for web browsing, 2012 Safari is basically unusable.
I recommend purchasing an affordable SATA SSD and replacing the old hard drive. A 500GB Crucial SATA SSD is cheap, everything will run MUCH faster, and you won't have to worry about accidentally losing something important from your old disk. An external USB enclosure for the old drive will allow you to access all the files from your original setup.
Getting a 64-bit installer ISO to boot on this machine has become more complicated over the years. The 64-bit install ISOs for many Linux distributions no longer contain a boot image for 32-bit EFIs, nor do they typically support legacy BIOS booting from a master boot record (MBR). If you try to boot a 64-bit USB ISO and the drive doesn't appear in the boot menu, this is probably the reason!
To make it as clear as possible, your install media needs to either:
- boot in legacy MBR mode
- or contain a 32-bit EFI image
So, your ISO boot options are:
- use a 32-bit distribution, which will support one of the above out of the box
- hack the 64-bit ISO of your desired distribution to boot in MBR mode
- use a 64-bit distribution that supports 32-bit EFIs, such as Debian's "multi-arch" ISO
The first is straighforward. Just look for the i386 version when downloading the installer ISO.
Matt Gadient has detailed instructions for converting 64-bit DVD ISOs to boot in MBR legacy mode. If you have a working DVD drive, this might be an option.
Debian has a "multi-arch" ISO that contains both 32-bit and 64-bit EFI images. This is both official and current (though maybe I should be concerned that it's not linked from the downloads page)... I'll be using this and preparing a USB thumb drive from another computer.
The WiFi driver firmware is closed-source and not available on the official install media. The simplest option is to use ethernet during install and install the 802.11 drivers afterward.
The only way to get the iSight working is to lift the firmware off a MacOS installation (though you can probably find the file online somewhere). Details are below, but you'll want to make sure you have a copy of the driver before wiping your old hard disk. In my case, I've replaced my OS X drive with an SSD. This has the additional benefit that I can access all of my old files from the old disk, if necessary.
With all that out of the way, here are the complete instructions for welcoming your 2006 iMac into the year 2022.
Before you do anything else, copy the proprietary iSight firmware to a safe place. You'll need this file after you install Linux in order to get the camera working. It's on your iMac's drive at the following location:
/System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBVideoSupport.kext/Contents/MacOS/AppleUSBVideoSupport
Should you miss this step, you'll probably have luck finding a copy of this file online. That said, I worry about some of those links eventually disappearing from the internet, so best not to skip this step.
We're going to reformat whatever's in your machine, so back up your iMac's drive -- or better, replace it with an SSD and keep the original as a backup.
I recommend replacing the original ATA hard disk with a new SATA SSD for performance reasons alone. A Crucial MX500 is a good choice. It's currently under $70 on Amazon and probably cheaper when you read this. You'll also need a 2.5" to 3.5" adapter to mount it in the old drive's space.
iFixit has a decent guide for replacing the drive. I think they also sell the necessary tools if you don't have them. You'll need a long, slender driver and variously sized torx bits.
Note: it's really hard getting the case off. There are hidden latches at the top that you're supposed to be able to depress by pushing a plastic card into a slot at the back of the machine. It took me a very long time to finally get the latch to disengage. Take your time and be patient -- it'll eventually come free. I believe there's a less invasive way to pull the latches using a strong neodymium magnet, but I don't have one and can't confirm it works. It's worth a shot if you have a strong magnet, because the card-latch trick is a real pain.
Note 2: take this opportunity to use some compressed air and a vacuum to thourougly clean things out. The computer is a decade and half old and full of dust bunnies. This will help with ventilation and can prevent overheating and premature component failure.
You can also buy a cheap external enclosure to access files on the old disk via USB.
External 3.5" SATA USB Enclosure
Download the latest Debian multi-arch network install ISO here (currently, debian-11.4.0-amd64-i386-netinst.iso "Bullseye"): https://cdimage.debian.org/debian-cd/current/multi-arch/iso-cd/
The multi-arch network install ISO (amd64-i386-netinst) should have a 32-bit EFI boot image and (unlike the i386 version) it will install the 64-bit kernel and user-space software.
Use your favorite disk imaging method or just use the unix 'dd' to write the ISO to a USB stick.
NOTE: make sure to replace sdX with you actual usb device. Be careful not to accidentally use the device for your computer's main drive!
dd if=debian-11.4.0-amd64-i386-netinst.iso of=/dev/sdX bs=1M status=progress
Boot your iMac with the USB drive plugged in and hold down the option key. It should appear as an EFI bootable removable disk. Grub will load and you can begin the Debian installer. My USB stick takes absolutely forever to boot, so be patient even if it appears to be locked up.
The network installer requires internet access to download and install packages. However, drivers for WiFi aren't installed yet. You can install these from USB somehow, but I'd recommend just plugging your computer into ethernet during this portion of installation.
Connect to ethernet, and tell Debian to ignore/skip any proprietary drivers during installation.
It's proabably also advisable to use a USB mouse until after installation when the wireless drivers are known to be working.
By default, Debian might want to format the drive with a GPT partitioning scheme. This is not what you want for legacy BIOS mode. Instead, you'll want to manually partition the drive with legacy "msdos" style partitions.
The first partition will hold necessary boot files: the kernel, init ramdisk, and grub. In an MBR partitioning scheme, the MBR sits right in front of this partition as well. I think it only needs to be in the first 2GB for the legacy bootloader to find it, but it's recommended to place this partition first. It doesn't need to be large. I configured mine with 500MB.
Creating a generous partition for swap, since it's difficult to resize this later. I recommend 2 times the maximum size of RAM you'll ever be likely to install. If you ever want to enable hibernation, this will make that task easy.
The final partition can fill the remainder of the disk. It will be formatted ext4 and will be the root filesystem mounted on /.
| Partition | Size | Type | Flags | Mount point |
|---|---|---|---|---|
| /dev/sda1 | 500MB | ext4 | boot | /boot |
| /dev/sda2 | 8GB | swap | ||
| /dev/sda3 | +100% | ext4 | / |
The Debian installer should install Grub to the MBR if your drive was formatted correctly. It may warn you that the system booted in EFI mode but you are installing in legacy MBR mode. That's what you want, so you can safely allow it to proceed.
Reboot and remove the USB drive. When the iMac chimes, hold down the option key. You should see a hard disk icon appear, with the strange word "Windows" written beneath. Close your eyes, imagine "Linux" and hit enter to boot into the Grub menu.
NOTE: If you don't see the disk or Grub doesn't load... It's possible the drive wasn't correctly partitioned or grub failed to install correctly to the MBR. Reboot with the USB install disk and choose "Graphical Rescue Mode" mode in the Grub "Advanced Options". Select your root partition (Ie. /dev/sda3 or wherever you put /). From here you can inspect your drive's partition information. If you screwed up, recreate the correct partition table and start the installation process over.
If the partition information looks alright, it might just be that grub didn't install correctly. In the recovery menu, you can "Execute a shell in /dev/sda3". At the shell prompt, run grub-install /dev/sda to attempt to reinstall grub correctly to the MBR. Exit, reboot, and hit option again to select to boot from the hard disk.
At the Grub menu, press "e" to edit the boot parameters and add the "nomodeset" kernel parameter to the linux line. This will likely be needed on the first boot until a couple of changes are made in the next steps.
Log in with your user account, and run "su -" in a terminal window to become the root user. Run the following to give your user account sudo permissions:
adduser YOURUSERNAME sudo
Later, when you're done with installing everything and you've confirmed sudo is working, you might consider disabling login on the root account with:
sudo passwd -l root
Wayland has very serious glitching issues with this video hardware once acceleration is working. Oddly, the mouse cursor appears fine, but the background textures in gdm and other user interface elements are glitchy and smeared about the screen. There must be something Wayland is using that is not supported by the hardware. XOrg runs almost perfectly, however, so you can just disable Wayland and pretend you didn't see this.
Edit /etc/gmd3/daemon.conf and remove the comment from the following line:
WaylandEnable=false
Add the non-free and contrib sources to the apt package manager. You can do this by checking a couple boxes in the "Software and Updates" application, or you can edit /etc/apt/sources.list and add "non-free contrib" at the end of every deb and deb-src line (after "main"). It'll look something like this:
deb http://deb.debian.org/debian/ bullseye main non-free contrib
deb-src http://deb.debian.org/debian/ bullseye main non-free contrib
deb http://security.debian.org/debian-security bullseye-security main non-free contrib
deb-src http://security.debian.org/debian-security bullseye-security main non-free contrib
deb http://deb.debian.org/debian/ bullseye-updates main non-free contrib
deb-src http://deb.debian.org/debian/ bullseye-updates main non-free contrib
Save and then update your packages:
apt-get update
apt-get dist-upgrade
Finally, we can install the video driver firmware and wireless drivers.
apt-get install firmware-amd-graphics
apt-get install firmware-b43-installer
Now edit /etc/default/grub and change the GRUB_CMDLINE_LINUX_DEFAULT to add "radeon.dpm=1 radeon.modeset=1 radeon.pcie_gen2=0". Mine looks like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet radeon.dpm=1 radeon.modeset=1 radeon.pcie_gen2=0"
What those are for:
- radeon.modeset=1 enables kernel modesetting on the video card, essentially the opposite of nomodeset (and probably enabled by default if things are working).
- radeon.dpm=1 ensures that display power management is running.
- radeon.pcie_gen2=0 this one forces the card to run in pcie gen1 mode. Without this setting I had numerous video compositing and text glitches in gnome.
I don't much care for the background image at boot. You can disable it by adding the line:
GRUB_BACKGROUND=""
When you're done changing things, you need to run:
sudo grub-update
Copy the AppleUSBVideoSupport file (that you saved earlier) to your home directory. The following command with install the isight-firware-tools, which will extract the firmware from this file and install it to the correct place.
sudo apt-get install isight-firmware-tools
During installation, it will prompt you for the location of AppleUSBVideoSupport. Change this to /home/YOURUSERNAME/AppleUSBVideoSupport (or to whatever location you placed the file). If you make a mistake, you can run sudo ift-extract -a [path_to_AppleUSBVideoSupport] with the correct path.
After reboot, you can use the pre-installed "Cheese" program to test your camera. Frankly, the camera quality is not that great. Ah well.
Reboot your iMac and almost everything should be working now. Here are some things to confirm:
- Xorg should have booted properly. If the screen looks really corrupted, see above about disabling Wayland.
- Run
sudo dmesg |grep drmand confirm the accelerated video card driver is now functioning. You should see a message about modesetting being enabled, as well as a bunch of other information about the graphics card (detected as an RV530). - WiFi should be working. You can unplug from Ethernet now and configure your WiFi settings.
- Bluetooth should be working. Set up your wireless mouse, etc.
- Suspend should work correctly. The light on the iMac will "breathe" when the machine is in suspend mode and hitting the power button once should reanimate everything.
NOTE: if you forgot to disable Wayland your screen is probably a glitchy mess at this point. You'll need to switch to a text console with ctl-alt-F3 to get anything done. Wayland glitches when video acceleration is finally working on this hardware, and the screen will be incomprehensible. See disabling Wayland above.
The default theme is perfect for my other computers, but the 2006 iMac is particularly enjoyable with a few updates.
apt-get install git gnome-tweaks gnome-shell-extension-dashtodock
There are a lot of options but the defaults are a pretty nice BigSur-like theme for gnome. More details and examples are on the author's github: https://github.com/vinceliuice/WhiteSur-gtk-theme
git clone https://github.com/vinceliuice/WhiteSur-gtk-theme.git
cd WhiteSur-gtk-theme
sudo ./install.sh
You can similarly tweak the look of Firefox, the dash to dock extension, and the gdm login screen:
sudo ./tweaks.sh -f -g -d
Just a few other tweaks from the same theme author. These make your icons and backgrounds snazzy.
Icons:
git clone https://github.com/vinceliuice/WhiteSur-icon-theme.git
cd WhiteSur-icon-theme
sudo ./install.sh
Desktop and login backgrounds:
git clone https://github.com/vinceliuice/WhiteSur-wallpapers.git
cd WhiteSur-wallpapers
sudo install-wallpapers.sh
Cursors:
git clone https://github.com/vinceliuice/WhiteSur-cursors.git
cd WhiteSur-cursors
sudo install.sh
- Enable extensions.
- In extensions, enable Dash to dock
- Position on bottom
- Set to use default theme
- In appearance settings, select:
- Themes: WhiteSur-light
- Cursor: WhiteSur-cursors
- Icons: WhiteSur
- Background: /usr/share/backgrounds/WhiteSur-light.jpg
- Lock Screen Image: /usr/share/backgrounds/WhiteSur-light.jpg
- Window Titlebars:
- Enable Maximize and Minimize buttons
- Placement: Left
You might need to reboot before all of these changes take effect and look consistent.
NOTE: Gnome Tweaks is a little glitchy with left button placement enabled. You need to stretch the window wider every time you run it or it awkwardly collapses the menu content. Fortunately, I haven't seen other apps with this issue.
The gdm logo setting is in /etc/gdm3/greeter.dconf-defaults. Edit this file and look for the "[org/gnome/login-screen]" section. Add the following line to remove the logo from the login screen:
logo=''
That's about everything. Reboot and enjoy your new 2022 iMac 5,1. Web Browsing, Email, Multimedia -- all the things!
Performance-wise, it's an enjoyable computer in 2022. It's showing it's age in a few places, of course: you might encounter an occasional video driver glitch. Fullscreen youtube is not great. However, Youtube works quite well in a window or theater mode. Aside from these small gripes, it's a fun computer to use. Thanks to the SSD upgrade, many things even seem faster than when this iMac was new.
