115 lines
3.8 KiB
ReStructuredText
115 lines
3.8 KiB
ReStructuredText
Getting Started
|
|
###############
|
|
|
|
Liminix is very configurable, which can make it initially daunting
|
|
especially if you're learning Nix or Linux or networking concepts at
|
|
the same time. In this section we build some "worked example" Liminix
|
|
images to introduce the concepts. If you follow the examples exactly,
|
|
they should work. If you change things as you go along, they may work
|
|
differently or not at all, but the experience should be educational
|
|
either way.
|
|
|
|
|
|
.. warning:: The first example we will look at runs under emulation,
|
|
so there is no danger of bricking your hardware
|
|
device. For the second example you may (if you have
|
|
appropriate hardware and choose to do so) flash the
|
|
configuration onto an actual router. There is always a
|
|
risk of rendering the device unbootable when you do this,
|
|
and various ways to recover depending on what went wrong.
|
|
We'll write more about that at the appropriate point
|
|
|
|
|
|
Requirements
|
|
************
|
|
|
|
You will need a reasonably powerful computer running Nix. Devices
|
|
that run Liminix are unlikely tohave the CPU power and disk space to
|
|
be able to build it in situ, so the build process is based around
|
|
"cross-compilation" from another computer. The build machine can be
|
|
any reasonably powerful desktop/laptop/server PC running NixOS.
|
|
Standalone Nixpkgs installations on other Linux distribuions or MacOS
|
|
also ought to work (but I haven't tested that configuration)
|
|
|
|
|
|
Running in Qemu
|
|
***************
|
|
|
|
Clone the Liminix git repository and change into its directory
|
|
|
|
|
|
.. code-block:: console
|
|
|
|
git clone https://gti.telent.net/dan/liminix
|
|
cd liminix
|
|
|
|
Now build Liminix
|
|
|
|
.. code-block:: console
|
|
|
|
nix-build -I liminix-config=./examples/hellonet.nix \
|
|
--arg device "import ./devices/qemu" -A outputs.default
|
|
|
|
In this command ``liminix-config`` points to the configuration for the
|
|
device (services, users, filesystem, secrets) and ``device`` is the
|
|
file for your hardware device definition. ``outputs.default`` tells
|
|
Liminix to build the appropriate image output appropriate to
|
|
flash to the hardware device: for the qemu "hardware" it's an alias
|
|
for ``outputs.vmbuild``, which creates a directory containing a root
|
|
filesystem image and a kernel.
|
|
|
|
.. tip:: The first time you run this it may take several hours,
|
|
because it builds all of the dependencies including a full
|
|
MIPS gcc and library toolchain. Once those intermediate build
|
|
products are in the nix store, subsequent builds will be much
|
|
faster - practically instant, if nothing has changed.
|
|
|
|
Now you can try it:
|
|
|
|
.. code-block:: console
|
|
|
|
nix-shell --run "mips-vm ./result/vmlinux ./result/rootfs"
|
|
|
|
This starts the Qemu emulator to run the Liminix configuration you
|
|
just built. It connects the Liminix serial console and the `QEMU
|
|
monitor <https://www.qemu.org/docs/master/system/monitor.html>`_ to
|
|
stdin/stdout. Use ^P (not ^A) to switch to the monitor.
|
|
|
|
You should now see Linux boot messages and after a few seconds be
|
|
presented with a login prompt. You can login on the console as
|
|
``root`` (no password) and poke around to see what processes are
|
|
running. Run ``shutdown`` to shut it down cleanly, or press ^P then
|
|
type ``exit`` at the monitor to stop it suddenly.
|
|
|
|
To see that it running an ssh service we need to connect to its
|
|
emulated network. Start the machine again, if you had stopped it,
|
|
and open up a second terminal on your build machine. We're going to
|
|
run another virtual machine attached to the virtual network, which will
|
|
request an IP address from our Liminix system and give you a shell
|
|
you can run ssh from.
|
|
|
|
|
|
|
|
|
|
- using modules
|
|
|
|
- link to module reference
|
|
|
|
- creating custom services
|
|
|
|
- longrun or oneshot
|
|
- dependencies
|
|
- outputs
|
|
|
|
- creating your own modules
|
|
|
|
- hacking on Liminix itself
|
|
|
|
- contributing
|
|
|
|
- external links and resources
|
|
|
|
- module reference
|
|
|
|
- hardware device reference
|