More docs

README.md

@@ -1,9 +1,9 @@
 # Iconograph
 
-Iconograph ("icon") is a system for building and deploying Linux system images.
+Iconograph ("icon") is a system for building and deploying Unbut system images.
 It allows you to distribute your software intended to run on real hardware or
 inside a container as a single unit with its system dependencies, and to roll
-forward and backward in a secure, repeatable manner.
+forward and backward in a secure, repeatable, staged manner.
 
 ## Setup
 
@@ -12,3 +12,23 @@ sudo apt-get install --assume-yes git grub-pc xorriso squashfs-tools openssl pyt
 git clone https://github.com/robot-tools/iconograph.git
 cd iconograph
 ```
+
+## Image creation
+
+### Overview
+
+Icon creates images by merging the kernel and boot system of a desktop live CD
+with a server/custom filesystem. You'll need to download the desktop live CD
+ISO for the version that you're building. You can get them [http://mirror.pnl.gov/releases/](here).
+
+### Serving
+
+Images are fetched via HTTP. You should write images to a directory accessible
+via HTTP.
+
+### Simple image build
+
+```bash
+# Must run as sudo to mount/umount images, tmpfs, and overlayfs
+sudo server/build_image.py --image-dir=/output/path --release=trusty --source-iso=path/to/ubuntu-14.04.4-desktop-amd64.iso
+```