burrow-pi-img/README.md

#TODO

1. Simplify running a single stage
2. Documentation

#Dependencies

quilt kpartx realpath qemu-user-static debootstrap zerofree pxz

#Config

Upon execution, build.sh will source the file config in the current working directory. This bash shell fragment is intended to set needed environment variables.

The following environment variables are supported:

• IMG_NAME, the name of the distribution to build (required)
• APT_PROXY, proxy/cache URL to be included in the build

A simple example for building Raspbian:

IMG_NAME='Raspbian'

#Stage Anatomy

#Raspbian Stage Overview

The build of Raspbian is divided up into several stages for logical clarity and modularity. This causes some initial complexity, but it simplifies maintenance and allows for more easy customization.

• Stage 0, bootstrap. The primary purpose of this stage is to create a usable filesystem. This is accomplished largely through the use of debootstrap, which creates a minimal filesystem suitable for use as a base.tgz on Debian systems. This stage also configures apt settings and installs raspberrypi-bootloader which is missed by debootstrap. The minimal core is installed but not configured, and the system will not quite boot yet.

• Stage 1, truly minimal system. This stage makes the system bootable by installing system files like /etc/fstab, configures the bootloader, makes the network operable, and installs packages like raspi-config. At this stage the system should boot to a local console from which you have the means to perform basic tasks needed to configure and install the system. This is as minimal as a system can possibly get, and its arguably not really usable yet in a traditional sense yet. Still, if you want minimal, this is minimal and the rest you could reasonably do yourself as sysadmin.

• State 2, lite system. This stage produces the Raspbian-Lite image. It installs some optimized memory functions, sets timezone and charmap defaults, installs fake-hwclock and ntp, wifi and bluetooth support, dphys-swapfile, and other basics for managing the hardware. It also creates necessary groups and gives the pi user access to sudo and the standard console hardware permission groups.

  There are a few tools that may not make a whole lot of sense here for development purposes on a minimal system such as basic python and lua packages as well as the build-essential package. They are lumped right in with more essential packages presently, though they need not be with pi-gen. These are understandable for Raspbian's target audience, but if you were looking for something between truly minimal and Raspbian-lite, here's where you start trimming.

• Stage 3, desktop system. Here's where you get the full desktop system with X11 and LXDE, web browsers, git for development, Raspbian custom UI enhancements, etc. This is a base desktop system, with some development tools installed.

• Stage 4, complete Raspbian system. More development tools, an email client, learning tools like Scratch, specialized packages like sonic-pi and wolfram-engine, system documentation, office productivity, etc. This is the stage that installs all of the things that make Raspbian friendly to new users.