nixpkgs/nixos/doc/manual/installation/installing-pxe.xml

<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-booting-from-pxe">
 <title>Booting from the <quote>netboot</quote> media (PXE)</title>

 <para>
  Advanced users may wish to install NixOS using an existing PXE or iPXE setup.
 </para>

 <para>
  These instructions assume that you have an existing PXE or iPXE
  infrastructure and simply want to add the NixOS installer as another option.
  To build the necessary files from a recent version of nixpkgs, you can run:
 </para>

<programlisting>
nix-build -A netboot.x86_64-linux nixos/release.nix
</programlisting>

 <para>
  This will create a <literal>result</literal> directory containing: *
  <literal>bzImage</literal> – the Linux kernel * <literal>initrd</literal>
  – the initrd file * <literal>netboot.ipxe</literal> – an example ipxe
  script demonstrating the appropriate kernel command line arguments for this
  image
 </para>

 <para>
  If you’re using plain PXE, configure your boot loader to use the
  <literal>bzImage</literal> and <literal>initrd</literal> files and have it
  provide the same kernel command line arguments found in
  <literal>netboot.ipxe</literal>.
 </para>

 <para>
  If you’re using iPXE, depending on how your HTTP/FTP/etc. server is
  configured you may be able to use <literal>netboot.ipxe</literal> unmodified,
  or you may need to update the paths to the files to match your server’s
  directory layout
 </para>

 <para>
  In the future we may begin making these files available as build products
  from hydra at which point we will update this documentation with instructions
  on how to obtain them either for placing on a dedicated TFTP server or to
  boot them directly over the internet.
 </para>
</section>