NixOS on MBP

This is a repo that will house notes and scripts related to getting NixOS running on a newer generation (late 2013+) MacBook Pro laptop (Retina).

Preparing Installation Media

Contrary to other reports on the internet (in the wild) you do not need to prerpare your bootable USB installer on another Linux distro.

You should be using 16.03 or 16.09 images at this point!

As of 2016-10-15 here are the latest nixos image download locations:

• NixOS 16.09

Download the minimal ISO from the link above.

The command I used on my NixOS box was the following, though on OSX you should be able to use /dev/disk2 or similar after unmounting the USB drive in OSX.

When preparing your USB install drive on Linux run:

sudo dd bs=4M if=path/to/nixos-minimal-16.09-x86_64-linux.iso of=/dev/sdc

When preparing your USB install drive on OS X or BSD-based distributions run:

sudo dd bs=4m if=path/to/nixos-minimal-16.09-x86_64-linux.iso of=/dev/disk2

Before Installing

You will need to resize your OSX partition. I did this by booting into the OSX Recovery partition and using the Disk Utility from there.

To boot into the Recovery partition you hold down the Cmd+R keys on boot startup until you see it enter Recovery mode.

Boot USB Drive

Boot from the USB drive by holding down the Option key during the boot startup tone until you see options of devices to boot from.

You will likely need to choose the second option called 'EFI Boot'.

Preparing Partitions in Stage2

If you are unsure on how to configure your partitions consult the man gdisk. I suggest the following basic setup (this is what I did):

$ sudo gdisk -l /dev/sda

GPT fdisk (gdisk) version 0.8.8

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 490234752 sectors, 233.8 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): XXXXXXXXXXXXXXXXXXXXXXXX
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 490234718
Partitions will be aligned on 8-sector boundaries
Total free space is 6 sectors (3.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
   2          409640        98957655   47.0 GiB    AF05  Customer
   3        XXXXXXXX       XXXXXXXXX   620.0 MiB   AB00  Recovery HD
   4       XXXXXXXXX       XXXXXXXXX   170.0 GiB   8300  nixosroot
   5       XXXXXXXXX       XXXXXXXXX   16.0 GiB    8200  nixosswap

I did this with the following commands after stage2 loaded in the NixOS installer:

# cryptsetup luksFormat /dev/sda4
# cryptsetup luksOpen /dev/sda4 nixosroot
# mkfs.ext4 /dev/mapper/nixosroot
# mkswap -L nixosswap /dev/sda5

If you do not already have a vfat filesystem for boot images you will need to run the following command (I didn’t need to do this):

# mkfs.vfat /dev/sda1

Now we need to mount the new or existing filesystems:

# mount /dev/mapper/nixosroot /mnt
# mkdir /mnt/boot
# mount /dev/sda1 /mnt/boot
# swapon /dev/disk/by-label/nixosswap

Make sure you mount /dev/sda1 under /mnt/boot.

After that run: nixos-generate-config --root /mnt

After this you may want to modify the configuration.nix to include gummiboot.

Then run: nixos-install

Configuration Post-Install

My /etc/nixos/configuration.nix for the MBP can be found at etc/nixos/configuration.nix.

Some parts of note that are required for the MBP are:

Boot Options

Use gummiboot. I got gummiboot working straight away.

{
  # Other stuff up here....

  boot.loader.grub.enable = false;
  boot.loader.systemd-boot.enable = true;
  # Whether or not the installation process should modify EFI boot variables
  boot.loader.efi.canTouchEfiVariables = true;
  # If you rely on a dirty /tmp dir you are doing it wrong. Your laptop will
  # never be cattle.
  boot.cleanTmpDir = true;
  # This gets your audio output and input (mic) working
  boot.extraModprobeConfig = ''
    options libata.force=noncq
    options resume=/dev/sda5
    options snd_hda_intel index=0 model=intel-mac-auto id=PCH
    options snd_hda_intel index=1 model=intel-mac-auto id=HDMI
    options snd_hda_intel model=mbp101
    options hid_apple fnmode=2
  '';

  # some other stuff below here
}

See the full base configuration at configuration.nix.

Tidbit: Audio

If you use xmonad and you want to attach your Fn keys to the appropriate audio behaviors you are accustomed to on OSX/Darwin then you can take a look at my xmonad.hs file.

For those just interested in the raw commands here they are below:

$ amixer -q set Master toggle # mute/unmute
$ amixer -q set Master 5%- # decrease volume by 5%
$ amixer -q set Master 5%+ # increase volume by 5%

Tidbit: Brightness / Visual Tempurature

Some of you may be familiar with OSX apps that changes your brightness and screen tone based on the time of day.

On Linux the best one I could find was redshift which is configurable in NixOS via the builtin module.

Here is an excerpt from my latest /etc/nixos/configuration.nix file for redshift configs:

  services.redshift.enable = true;
  services.redshift.brightness.day = "0.8";
  services.redshift.brightness.night = "0.4";
  services.redshift.latitude = "0.0000";
  services.redshift.longitude = "0.0000";

For the raw commands to use to increase or decrease brightness see below:

$ cat /sys/class/backlight/acpi_video0/brightness # echos current brightness level
10
$ cat /sys/class/backlight/acpi_video0/max_brightness # echos max brightness level
100
$ echo 25 | sudo tee /sys/class/backlight/acpi_video0/brightness # sets brightness to 25/100
$ cat /sys/class/backlight/acpi_video0/brightness
25

HTH!