README: extend

README.md

@@ -1,7 +1,24 @@
 # nixos-remote - install nixos everywhere via ssh
 
+nixos-remote makes it possible to install nixos from Linux machines reachable via ssh.
+Under the hood uses a [kexec image](https://github.com/nix-community/nixos-images#kexec-tarballs) to boot
+into a NixOS installer from a running Linux system.
+It then uses [disko](https://github.com/nix-community/disko) to partition and
+format the disks on the target system before it installs the user provided nixos
+configuration.
+
+## Requirements
+
+- x86_64 Linux system with kexec support (most x86_64 machine do have kexec support)
+- At least 2.5GB RAM (swap does not count). If you do not have enough RAM you
+  will see failures unpacking the initrd), this is because kexec needs to load
+  the whole nixos into memory.
+- DHCP: Currently nixos-remote requires that the network of the machine, offers DHCP for
+  dynamic address configuration or else the booted nixos will not have any
+  network set up.
+
 ## Usage
-Needs a repo with your configurations with flakes. for a minimal example checkout https://github.com/Lassulus/flakes-testing.
+Needs a repo with your configurations with flakes. For a minimal example checkout https://github.com/Lassulus/flakes-testing.
 
 Your NixOS configuration will also need a [disko](https://github.com/nix-community/disko) configuration  as we can see in
 our [example](https://github.com/Lassulus/flakes-testing/blob/216b3023c01581359599f5bc9ae48eeee2617627/flake.nix#L13)
@@ -14,7 +31,3 @@ Afterwards you can just run:
 
 The parameter passed to `--flake` should point to your nixos configuration
 exposed in your flake (`nixosConfigurations.your-system` in the example above).
-
-Currently nixos-remote requires that the network of the machine, offers DHCP for
-dynamic address configuration or else the booted nixos will not have any
-network set up.