MixOS Manual

Packages to be included in the runtime system and available in $PATH.

Type: list of package

Default:

[ ]

Declared by:

Additional arguments passed to each module in addition to ones like lib, config, and pkgs, modulesPath.

This option is also available to all submodules. Submodules do not inherit args from their parent module, nor do they provide args to their parent module or sibling submodules. The sole exception to this is the argument name which is provided by parent modules to a submodule and contains the attribute name the submodule is bound to, or a unique generated name if it is not bound to an attribute.

Some arguments are already passed by default, of which the following cannot be changed with this option:

For NixOS, the default value for this option includes at least this argument:

Type: lazy attribute set of raw value

Default:

{ }

Declared by:

A list of additional packages supplying kernel modules.

Type: list of package

Default:

[ ]

Example:

[ config.boot.kernelPackages.nvidia_x11 ]

Declared by:

List of packages containing firmware files. Such files will be loaded automatically if the kernel asks for them (i.e., when it has detected specific hardware that requires firmware to function). If multiple packages contain firmware files with the same name, the first package in the list takes precedence. Note that you must rebuild your system if you add files to any of these directories.

Type: list of package

Default:

[ ]

Declared by:

Other initrd files to prepend to the initrd MixOS builds. The kernel unpacks the concatenated archives in order, each one either a plain cpio archive or a compressed one.

Since MixOS owns the initrd, this is how CPU microcode gets supplied. Microcode is the one thing here that must be an uncompressed cpio archive, and must come first (see lib.mkOrder), because the kernel scans for it in the raw initrd before unpacking any of it.

Type: list of absolute path

Default:

[ ]

Example:

[ "${pkgs.microcode-intel}/intel-ucode.img" ]

Declared by:

Kernel modules to load during early bootup.

Type: list of string

Default:

[ ]

Declared by:

A kernel package-set containing a kernel attribute and optionally one or more kernel modules (à la pkgs.linuxPackagesFor …).

Type: raw value

Default:

"pkgs.linuxPackages_7_2"

Declared by:

A list of additional patches to apply to the kernel. See NixOS documentation for more information.

Type: list of (attribute set)

Default:

[ ]

Declared by:

Extra module aliases, keyed by alias (shell-style wildcards allowed).

Type: attribute set of string

Default:

{ }

Example:

{
  "usb:v1D6Bp0001d*" = "my_driver";
}

Declared by:

Kernel modules that will not be loaded automatically. Note that this only prevents a module from being loaded by one of its aliases (e.g. by the mdev $MODALIAS rule); modprobing a module by its real name still loads it, use boot.modprobe.install with /bin/false to prevent that as well.

Type: attribute set of boolean

Default:

{ }

Example:

{
  nouveau = true;
}

Declared by:

Commands to run instead of inserting a module into the kernel, keyed by module name.

Type: attribute set of string

Default:

{ }

Example:

{
  nouveau = "/bin/false";
}

Declared by:

Module parameters to use when loading a module, keyed by module name. Definitions from multiple modules are joined with a space.

Type: attribute set of strings concatenated with " "

Default:

{ }

Example:

{
  i915 = "enable_psr=0";
}

Declared by:

Commands to run instead of removing a module from the kernel, keyed by module name.

Type: attribute set of string

Default:

{ }

Example:

{
  mymod = "/bin/rmmod --wait mymod";
}

Declared by:

Soft dependencies to load alongside a module, keyed by module name. Unlike real dependencies, a soft dependency failing to load does not fail the module being loaded.

Type: attribute set of strings concatenated with " "

Default:

{ }

Example:

{
  hid_generic = "pre: hid_multitouch";
}

Declared by:

Weak dependencies of a module, keyed by module name. These are not loaded along with the module, they only record that the modules belong together for tooling that consumes the information.

Type: attribute set of strings concatenated with " "

Default:

{ }

Example:

{
  mymod = "mymod_helper";
}

Declared by:

Attribute set of kernel Kconfig options that must be included in the kernel provided to mixos. Values (from lib.kernel) are asserted against the configured kernel, where lib.kernel.module is satisfied with either ‘y’ or ‘m’. Non-tristate values (lib.kernel.freeform) are asserted for equality, ignoring any quoting of string values. Options marked as optional (lib.kernel.option) are not asserted.

Type: attribute set of raw value

Default:

{ }

Example:

''
  {
    TMPFS = lib.kernel.yes;
    OVERLAY_FS = lib.kernel.module;
    LOG_BUF_SHIFT = lib.kernel.freeform "18";
  }
''

Declared by:

Enable watchdog integration. This ensures if the boot process fails, the system doesn’t hang indefinitely.

Type: boolean

Default:

true

Declared by:

Watchdog timeout.

Type: integer of at least 10

Default:

90

Declared by:

Files to place in /etc, keyed by their path relative to /etc. Each entry is either symlinked into the store or, if a mode is given, copied with that mode.

Type: attribute set of (submodule)

Default:

{ }

Example:

{ "hostname".source = pkgs.writeText "hostname" "my-machine"; }

Declared by:

Copy file to destination with permissions, or symlink if null.

Type: null or string

Default:

null

Example:

"0400"

Declared by:

Path to place in /etc

Type: absolute path

Declared by:

Groups to create in /etc/group.

Type: attribute set of (submodule)

Default:

{ }

Declared by:

Group ID. There is no automatic allocation, so this must be chosen, and kept unique, by hand.

Type: 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Declared by:

Name of the group, as it appears in /etc/group. Defaults to the attribute name.

Type: string

Default:

"‹name›"

Declared by:

Whether to enable hardware accelerated graphics drivers.

Type: boolean

Default:

false

Example:

true

Declared by:

The mesa package to use.

Type: package

Default:

pkgs.mesa

Declared by:

Additional packages to add to the driver lookup path. This is how OpenCL, VA-API and VDPAU drivers are made available, among others.

Type: list of package

Default:

[ ]

Example:

[ pkgs.intel-media-driver ]

Declared by:

Entries for busybox init’s /etc/inittab, keyed by a name used only for ordering with deps. Actions run in the order listed under action, not in the order entries are declared here.

Type: attribute set of (submodule)

Default:

{ }

Declared by:

Whether to enable this process.

Type: boolean

Default:

true

Declared by:

sysinit actions are started first, and init waits for them to complete. wait actions are started next, and init waits for them to complete. once actions are started next (and not waited for).

askfirst and respawn are started next. For askfirst, before running the specified process, init displays the line “Please press Enter to activate this console” and then waits for the user to press enter before starting it.

shutdown actions are run on halt/reboot/poweroff, or on SIGQUIT. Then the machine is halted/rebooted/powered off, or for SIGQUIT, restart action is exec’ed (init process is replaced by that process). If no restart action specified, SIGQUIT has no effect.

ctrlaltdel actions are run when SIGINT is received (this might be initiated by Ctrl-Alt-Del key combination). After they complete, normal processing of askfirst / respawn resumes.

Type: one of “sysinit”, “wait”, “once”, “respawn”, “askfirst”, “shutdown”, “restart”, “ctrlaltdel”

Declared by:

Names of other init entries this one must be ordered after. Ordering only applies within a single action: every name listed here must name an enabled entry with the same action as this one, or evaluation fails.

Type: list of string

Default:

[ ]

Example:

[
  "mount-state"
]

Declared by:

Specifies the process to be executed and it’s command line.

Type: string or package

Example:

"/bin/echo 'hello, world'"

Declared by:

This field is used by BusyBox init to specify the controlling tty for the specified process to run on. The contents of this field are appended to “/dev/” and used as-is. There is no need for this field to be unique, although if it isn’t you may have strange results. If this field is left blank, then the init’s stdin/out will be used.

Type: string

Default:

"null"

Example:

"tty1"

Declared by:

Rules to be interpreted by mdev, placed in /etc/mdev.conf.

Type: strings concatenated with “\n”

Declared by:

The mixos package to use.

Type: package

Default:

"pkgs.mixos"

Declared by:

/etc/os-release contents.

Type: open submodule of attribute set of (atom (null, bool, int, float or string))

Default:

{ }

Declared by:

The ID field of /etc/os-release, identifying the operating system.

Type: string

Default:

"mixos"

Declared by:

The VERSION_ID field of /etc/os-release.

Type: string

Default:

config.mixos.package.version

Declared by:

UUID of the erofs image, fixed for reproducibility.

Type: string

Default:

"cb67e325-87bc-4235-b2fd-cd5d54efe14b"

Declared by:

Whether to enable the mixos test backdoor service.

Type: boolean

Default:

false

Example:

true

Declared by:

The pkgs module argument.

Type: Nixpkgs package set

Default:

{ }

Declared by:

Long-running processes to supervise, keyed by service name. Each one becomes a service directory under /var/service, run by the runsvdir started from init.

Type: attribute set of (submodule)

Default:

{ }

Declared by:

Whether to enable this service.

Type: boolean

Default:

true

Declared by:

Specifies the process to be executed for this service.

Type: absolute path

Example:

/bin/httpd

Declared by:

Whether to enable persistence of state.

Type: boolean

Default:

false

Example:

true

Declared by:

The filesystem type of the state device.

Type: string

Example:

"ext4"

Declared by:

Program to initialize state, for example for formatting disks, creating device-mapper devices, etc. This program will run on every boot, thus it should be idempotent if the backing device has already been initialized.

Type: null or absolute path

Default:

null

Example:

pkgs.writeScript "state-init" "mkfs.ext4 /dev/sda"

Declared by:

The mount options to use when mounting the state device. Available options can usually be found in fs/<fstype>/super.c of the kernel source. In addition, any of the MOUNT_ATTR_* names can be used with name lowercased and the “MOUNT_ATTR_” prefix removed (see <linux.mount.h>).

Type: list of string

Default:

[ ]

Declared by:

The device being mounted.

Type: string

Example:

"/dev/sda"

Declared by:

Attribute set of derivations used to set up the system.

Type: open submodule of lazy attribute set of unspecified value

Default:

{ }

Declared by:

Users to create in /etc/passwd.

Type: attribute set of (submodule)

Default:

{ }

Declared by:

The GECOS field of the user’s /etc/passwd entry.

Type: string

Default:

""

Declared by:

ID of the user’s primary group. This is the raw ID rather than a name, so it must match the id of the intended entry in groups.

Type: 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Declared by:

Names of supplementary groups the user is a member of, on top of the primary group named by gid.

Type: list of string

Default:

[ ]

Declared by:

The user’s home directory. Nothing creates it, so a directory that does not otherwise exist stays missing.

Type: string

Default:

"/var/empty"

Declared by:

Name of the user, as it appears in /etc/passwd. Defaults to the attribute name.

Type: string

Default:

"‹name›"

Declared by:

The user’s login shell.

Type: absolute path

Default:

"/bin/nologin"

Declared by:

User ID. There is no automatic allocation, so this must be chosen, and kept unique, by hand.

Type: 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Declared by: