10.2 operating-system Reference

This section summarizes all the options available in operating-system declarations (see Using the Configuration System).

Data Type: operating-system

This is the data type representing an operating system configuration. By that, we mean all the global system configuration, not per-user configuration (see Using the Configuration System).

kernel (default: linux-libre)

The package object of the operating system kernel to use²⁴.

hurd (default: #f)

The package object of the Hurd to be started by the kernel. When this field is set, produce a GNU/Hurd operating system. In that case, kernel must also be set to the gnumach package—the microkernel the Hurd runs on.

Warning: This feature is experimental and only supported for disk images.

kernel-loadable-modules (default: ’())

A list of objects (usually packages) to collect loadable kernel modules from–e.g. (list ddcci-driver-linux).

kernel-arguments (default: %default-kernel-arguments)

List of strings or gexps representing additional arguments to pass on the command-line of the kernel—e.g., ("console=ttyS0").

bootloader

The system bootloader configuration object. See Bootloader Configuration.

label

This is the label (a string) as it appears in the bootloader’s menu entry. The default label includes the kernel name and version.

keyboard-layout (default: #f)

This field specifies the keyboard layout to use in the console. It can be either #f, in which case the default keyboard layout is used (usually US English), or a <keyboard-layout> record. See Keyboard Layout, for more information.

This keyboard layout is in effect as soon as the kernel has booted. For instance, it is the keyboard layout in effect when you type a passphrase if your root file system is on a luks-device-mapping mapped device (see Mapped Devices).

Note: This does not specify the keyboard layout used by the bootloader, nor that used by the graphical display server. See Bootloader Configuration, for information on how to specify the bootloader’s keyboard layout. See X Window, for information on how to specify the keyboard layout used by the X Window System.

initrd-modules (default: %base-initrd-modules)

The list of Linux kernel modules that need to be available in the initial RAM disk. See Initial RAM Disk.

initrd (default: base-initrd)

A procedure that returns an initial RAM disk for the Linux kernel. This field is provided to support low-level customization and should rarely be needed for casual use. See Initial RAM Disk.

firmware (default: %base-firmware)

List of firmware packages loadable by the operating system kernel.

The default includes firmware needed for Atheros- and Broadcom-based WiFi devices (Linux-libre modules ath9k and b43-open, respectively). See Hardware Considerations, for more info on supported hardware.

host-name

The host name.

hosts-file

A file-like object (see file-like objects) for use as /etc/hosts (see Host Names in The GNU C Library Reference Manual). The default is a file with entries for localhost and host-name.

mapped-devices (default: '())

A list of mapped devices. See Mapped Devices.

file-systems

A list of file systems. See File Systems.

swap-devices (default: '())

A list of UUIDs, file system labels, or strings identifying devices or files to be used for “swap space” (see Memory Concepts in The GNU C Library Reference Manual). Here are some examples:

(list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))

Use the swap partition with the given UUID. You can learn the UUID of a Linux swap partition by running swaplabel device, where device is the /dev file name of that partition.

(list (file-system-label "swap"))

Use the partition with label swap. Again, the swaplabel command allows you to view and change the label of a Linux swap partition.

(list "/swapfile")

Use the file /swapfile as swap space.

(list "/dev/sda3" "/dev/sdb2")

Use the /dev/sda3 and /dev/sdb2 partitions as swap space. We recommend referring to swap devices by UUIDs or labels as shown above instead.

It is possible to specify a swap file in a file system on a mapped device (under /dev/mapper), provided that the necessary device mapping and file system are also specified. See Mapped Devices and File Systems.

users (default: %base-user-accounts)

groups (default: %base-groups)

List of user accounts and groups. See User Accounts.

If the users list lacks a user account with UID 0, a “root” account with UID 0 is automatically added.

skeletons (default: (default-skeletons))

A list of target file name/file-like object tuples (see file-like objects). These are the skeleton files that will be added to the home directory of newly-created user accounts.

For instance, a valid value may look like this:

`((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
  (".guile" ,(plain-file "guile"
                         "(use-modules (ice-9 readline))
                          (activate-readline)")))

issue (default: %default-issue)

A string denoting the contents of the /etc/issue file, which is displayed when users log in on a text console.

packages (default: %base-packages)

A list of packages to be installed in the global profile, which is accessible at /run/current-system/profile. Each element is either a package variable or a package/output tuple. Here’s a simple example of both:

(cons* git                     ; the default "out" output
       (list git "send-email") ; another output of git
       %base-packages)         ; the default set

The default set includes core utilities and it is good practice to install non-core utilities in user profiles (see Invoking guix package).

timezone

A timezone identifying string—e.g., "Europe/Paris".

You can run the tzselect command to find out which timezone string corresponds to your region. Choosing an invalid timezone name causes guix system to fail.

locale (default: "en_US.utf8")

The name of the default locale (see Locale Names in The GNU C Library Reference Manual). See Locales, for more information.

locale-definitions (default: %default-locale-definitions)

The list of locale definitions to be compiled and that may be used at run time. See Locales.

locale-libcs (default: (list glibc))

The list of GNU libc packages whose locale data and tools are used to build the locale definitions. See Locales, for compatibility considerations that justify this option.

name-service-switch (default: %default-nss)

Configuration of the libc name service switch (NSS)—a <name-service-switch> object. See Name Service Switch, for details.

services (default: %base-services)

A list of service objects denoting system services. See Services.

essential-services (default: ...)

The list of “essential services”—i.e., things like instances of system-service-type and host-name-service-type (see Service Reference), which are derived from the operating system definition itself. As a user you should never need to touch this field.

pam-services (default: (base-pam-services))

Linux pluggable authentication module (PAM) services.

setuid-programs (default: %setuid-programs)

List of <setuid-program>. See Setuid Programs, for more information.

sudoers-file (default: %sudoers-specification)

The contents of the /etc/sudoers file as a file-like object (see local-file and plain-file).

This file specifies which users can use the sudo command, what they are allowed to do, and what privileges they may gain. The default is that only root and members of the wheel group may use sudo.

Scheme Syntax: this-operating-system

When used in the lexical scope of an operating system field definition, this identifier resolves to the operating system being defined.

The example below shows how to refer to the operating system being defined in the definition of the label field:

(use-modules (gnu) (guix))

(operating-system
  ;; ...
  (label (package-full-name
          (operating-system-kernel this-operating-system))))

It is an error to refer to this-operating-system outside an operating system definition.