Debian Trixie on an M1 Mac

When I visited home over the summer holidays, a family member mentioned that they didn’t really like the MacBook they purchased a few years ago. Having used Windows at work for decades, they just wanted the same experience on their personal device. I had brought my laptop home that originally came with Windows, but had since installed Debian. I offered to trade (and re-install Windows), in part because the one thing that bothered me about my (cheaper) laptop, was the screen. They accepted, and so I had a fresh M1 MacBook, and was curious if I could get Debian Trixie up and running.

Going Bananas

Debian maintains an excellent wiki page on running the operating system on M1 macs. I would say that the installation process was easier but scarier than other Debian installations I had done. Instead of downloading and flashing an .iso, all you need to do is run a single command from the mac terminal (which uses the Asahi Linux installer).

curl -L https://bananas.debian.net/install | sh

This command will guide you through all steps that you need to complete, however, it has some scary warnings. This is the final message you are presented with before the shutdown:

Please read the following instructions carefully. Failure to do so will leave your new installation in an unbootable state.

  1. Wait 25 seconds for the system to fully shut down.
  2. Press and hold down the power button to power on the system.
    • It is important that the system be fully powered off before this step, and that you press and hold down the button once, not multiple times. This is required to put the machine into the right mode.
  3. Release it once you see ‘Loading startup options…’ or a spinner.
  4. Wait for the volume list to appear.
  5. Choose ‘Debian 13’
  6. You will briefly see a ‘macOS Recovery’ dialog.
    • If you are asked to ‘Select a volume to recover’, then choose your normal macOS volume and click Next. You may need to authenticate with your macOS credentials.
  7. Once the ‘Debian installer’ screen appears, follow the prompts.

If you end up in bootloop or get a message telling you that macOS needs to be reinstalled, that means you didn’t follow the above properly.

Yikes! I made it through successfully to the other side, but I would be lying if I said I wasn’t sweating a bit through the process. macOS also presents you with some security warnings, which are presumably about the problem outlined below.

No LUKS Encryption

One of the requirements of most workplaces that support Bring Your Own Device (BYOD) is full disk encryption. While the Debian installer supports setting up LUKS encryption, the installation process from the Asahi script did not. Overall, the installation process was much simpler, for two reasons. It didn’t go through the steps for setting up a root user, and it didn’t go through the steps to setup partitions. It just took care of it in the way that it wanted. This could be because there was no easy way for the Asahi Linux team to integrate custom partitions, or they just wanted to make the process as smooth as possible for the user.

There is a blog post by David Alger that is often referenced to set LUKS up manually (though it was done on Fedora). I’m currently debating whether this is worth the effort.

Fallback option: running a virtual machine

The other option, and the one that I had been experimenting with over the past week, was running Debian through a virtual machine using UTM. The performance is slightly worse than the Asahi Linux option, and you have to deal with jumping through the macOS login screen and some shortcuts not working, but at least you would get the macOS security features out of the gate.

Conclusion

First, I wanted to say a huge congratulations and thank you to the Asahi Linux and Debian Bananas team, none of this is intended to take away from all the hard work that they have put in to make Linux available on Apple Silicon in the first place. If you want cool things, sometimes you have to put in the work. If anyone reading this has installed any distribution on an M series Mac, I would love to hear how it has been going for you. This post was written just a few hours after finishing the installation process, and so I don’t have a long-term perspective yet.