= Getting Spectrum
:page-parent: Build and Run
:page-nav_order: 2

// SPDX-FileCopyrightText: 2022-2023 Alyssa Ross <hi@alyssa.is>
// SPDX-License-Identifier: GFDL-1.3-no-invariants-or-later OR CC-BY-SA-4.0

To get Spectrum, you need to build it from source.  As long as you're
running Linuxfootnote:[Building from other operating systems might
work, but hasn't been tested.  Patches are welcome to support building
from other operating systems, as long as they're not too invasive.]
and have https://nixos.org/download.html[Nix] and https://git-scm.com/[git]
installed, it's very easy to do.

TIP: Before you start, consider setting up the
xref:binary-cache.adoc[Spectrum binary cache], which will save you a
lot of time waiting for builds.

== Trying Spectrum

If you want to try Spectrum out to get a feel for it, without
installing it, you can run it in a development VM with some example
applications.

[source,shell]
----
git clone https://spectrum-os.org/git/spectrum
cd spectrum/host/rootfs
nix-shell --run 'make run'
----

This builds just enough of Spectrum to try it out in a VM, but it will
still take a very long time.

== Installing Spectrum

To install Spectrum on a computer, you can use a USB drive as a
bootable Spectrum installer device.  When booting a system from the
installer device, you will be able to choose whether to try out
Spectrum without installing it on your system (as a live image), or to
install it to your computer's internal storage.

First, you need to build the Spectrum image:

[source,shell]
----
git clone https://spectrum-os.org/git/spectrum
nix-build spectrum/release/combined
----

If you haven't set up the xref:binary-cache.adoc[binary cache], this
will take a very long time.  When it's done, a symbolic link named
"result" will appear in the current directory, pointing to the
installer image.  Write that image to a USB drive, for example using
`dd` (command line) or
https://gitlab.com/bztsrc/usbimager[`usbimager`] (graphical, available
in Nixpkgs).  Boot your system from the USB drive, and you should see
a menu allowing you to choose between "Try Spectrum" and "Install
Spectrum".

NOTE: While it's possible to install Spectrum to your internal
storage, at this point in Spectrum's development there is not much
reason to, as OS updates are not yet implemented, and persistent
storage is not yet exposed to VMs.  Using the "Try Spectrum" option to
boot Spectrum will let you try out everything in Spectrum, without
having to go through the additional step of reinstalling Spectrum
every time you want to use a newer version.

CAUTION: Do not use Spectrum for anything important or sensitive as it is not
yet suitable for real-world use.  Many important security properties are
currently missing, and there is no procedure for updating to
new versions—you have to reinstall the OS.
