I ran out of space on my 2020 Macbook Pro M1. I'm not sure what it says about what kind of person I am, but to me that just meant I had to factory reset it. And if I was factory resetting it, I might as well boot it with Linux.

I spent some time (less than a week) on the Asahi Fedora Remix. Before this, I was using Nix Darwin, but Nix isn't available on Fedora.

The folks in the nix community put together some solid documention about booting NixOS on Apple Silicon. I figured it was worth a shot.

Installation#

The only significant change that I made was the initial install. Since I had already installed Fedora, I figured I could just install NixOS right onto that disk partition.

I built the ISO from scratch, made some configuration changes as per the nixos-apple-silicon docs, & installing the OS went sideways...

Power outage#

During the initial install, my machine died. Forgot to plug it in. Luckily, all of the changes were already written to disk, so I could just install from the /etc/nixos/configuration.nix file after mounting the disk again. After some time, the install went through fine.

Restart... And nothing :(

Das U-Boot Purgatory#

More specifically, I was stuck in the boot menu. Naturally, this was caused by me going off-script, installing NixOS over the Fedora install.

Now I've been a Linux enjoyer for while, but I haven't played much with any boot menus. From what I can tell, however, I needed to point to the new /boot partition I made for NixOS. Simple enough.

In U boot, we can printenv, which tells us everything we need to know.

The docs for the bootflow command can be found here

The bootcmd was bootflow scan -b. Hmmm...

With a bootflow list, we can see what we're working with:

Seq  Method   State   Uclass   Part   Name                       FileName
-------------------------------------------------------------------------------------------
0    efi_mgr  ready   (none)      0   <NULL>
1    efi      ready   nvme        4   nvme@27bccc000.blk#1.boot  /EFI/BOOT/BOOTARG64.EFI
-------------------------------------------------------------------------------------------

This looks promising. This issue is, it doesn't mean anything to me. It seemed clear that the <Null> and missing FileName were issues. So I tried booting off of the first bootflow and that did the trick.

bootflow select 1
bootflow boot

So it seems like we needed to boot the 1st bootflow instead of the 0th. This aligns with the docs for the -b option:

-b

    Boot each valid bootflow as it is scanned. Typically only the first bootflow matters, since by then the system boots in the OS and U-Boot is no-longer running. bootflow scan -b is a quick way to boot the first available OS. A valid bootflow is one that made it all the way to the loaded state. Note that if -m is provided as well, booting is delayed until the user selects a bootflow.

That means we needed to change the bootcmd to the following:

setenv bootcmd "bootflow scan ; bootflow select 1 ; bootflow boot"

Then saveenv, naturally.

Attempt II#

I also have a 2020 Mac Mini with the M1 chip. I figured I can't have just one of them on Asahi & the other on MacOS, that'd be cruel. Also, I already had the bootable USB for NixOS on Asahi.

This time around it was much smoother because there wasn't an existing Fedora partition.

Configuration#

Thanks to the reproducibility of Nix, I was able to reuse the majority of my configuration from the previous host. The code for this can be found in my nixos-config repo.