diff --git a/.gitignore b/.gitignore
index f592fe2..f02c58a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,5 @@
-/build
 apidoc.md
 apidoc.html
-psychos/
 *.cpio
 *.af
+/target
diff --git a/README.md b/README.md
index 7ead303..269ddcf 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,25 @@
 
 A lightweight, multi-user operating system for OpenComputers
 
+## Building
+
+### The kernel
+
+The kernel can be built using luapreproc:
+
+    ./luapreproc.lua module/init.lua kernel.lua
+
+### The boot filesystem
+
+A boot filesystem contains several things:
+
+ - The kernel, as init.lua
+ - The exec/ directory, as this contains all executables
+ - The lib/ directory, containing libraries
+ - The service/ directory, containing system services
+
+This has been automated in the form of build.sh, pending a real makefile.
+
 ## Documentation
 
 To generate function documentation, run:
diff --git a/build.sh b/build.sh
index c9ef01b..95b59eb 100755
--- a/build.sh
+++ b/build.sh
@@ -1,7 +1,5 @@
-#!/usr/bin/env bash
-mkdir build
-cd module
-cat sched.lua syslog.lua vt100.lua fs.lua iofs.lua loadfile.lua vt-task.lua io.lua dispmanager.lua init.lua > ../build/psychos.lua
-cd ..
-echo '_OSVERSION="PsychOS 2.0a0"' >> build/*
-echo sched\(\) >> build/*
+#!/bin/sh
+rm -r target/*
+mkdir target
+lua luapreproc.lua module/init.lua target/init.lua
+cp -r exec/ service/ lib/ target/