## How the build process works

The following process is followed to build images:

 * Iterate through all of the stage directories in alphanumeric order

 * Bypass a stage directory if it contains a file called
   "SKIP"

 * Run the script `prerun.sh` which is generally just used to copy the build
   directory between stages.

 * In each stage directory iterate through each subdirectory and then run each of the
   install scripts it contains, again in alphanumeric order. **These need to be named
   with a two digit padded number at the beginning.**
   There are a number of different files and directories which can be used to
   control different parts of the build process:

     - **00-run.sh** - A unix shell script. Needs to be made executable for it to run.

     - **00-run-chroot.sh** - A unix shell script which will be run in the chroot
       of the image build directory. Needs to be made executable for it to run.

     - **00-debconf** - Contents of this file are passed to debconf-set-selections
       to configure things like locale, etc.

     - **00-packages** - A list of packages to install. Can have more than one, space
       separated, per line.

     - **00-packages-nr** - As 00-packages, except these will be installed using
       the `--no-install-recommends -y` parameters to apt-get.

     - **00-patches** - A directory containing patch files to be applied, using quilt.
       If a file named 'EDIT' is present in the directory, the build process will
       be interrupted with a bash session, allowing an opportunity to create/revise
       the patches.

  * If the stage directory contains files called "EXPORT_NOOBS" or "EXPORT_IMAGE" then
    add this stage to a list of images to generate

  * Generate the images for any stages that have specified them

It is recommended to examine build.sh for finer details.