# Aimee OS Build Container Images

Prerequisites:

* `buildah`


## Gentoo Stage 3 Image

This image is used to bootstrap the base layer for Aimee OS build images.  To
build it, use the `gentoo-stage3.sh` build script.  This script takes a single
(optional) positional argument: the name of a Gentoo stage 3 tarball to use to
produce the container image.  If none is specified, the latest
`stage3-amd64-nomultilib-openrc` tarball is downloaded and used.

```sh
sh image-build/gentoo-stage3.sh
```


## Base Image

The Aimee OS base build image is a minimal environment based on Gentoo.  It
includes Portage and a basic build toolchain.  Building it requires a Stage 3
image to bootstrap the environment.  By default,
_aimee-os.org/gentoo/stage3-amd64-nomultilib-openrc:latest_ is used, but an
alternative image can be specified using the `-b`/`--base` argument to the
`base.sh` script.

```sh
sh image-build/base.sh
```


## Crossdev Image

This image includes a cross-compilation toolchain, generated by _crossdev_.  It
is built using the `cross.sh` script.  This script takes a `-t`/`--target`
argument, which specifies the toolchain to generate.  The default is
`aarch64-unknown-linux-gnu`.  This image is layered on top of the base image,
which can be specified using the `-b`/`--base` argument.  By default,
_aimee-os.org/build/base:latest_ is used.

```sh
sh image-build/cross.sh
```

## Build Image

The top-level image is based on the Crossdev image, and includes additional
tools for building an Aimee OS project.  It is built using the `build.sh` script.
As with the Crossdev image build script, this script accepts `-t`/`--target`
and `-b`/`--build` arguments, which specify the cross-compilation toolchain and
base image later, respectively.

```sh
sh image-build/build.sh
```

This image is "squashed," meaning it consists of only a single layer.  The Base
and Crossdev image layers are merged into the final layer when the image is
built.  This reduces the final size of the image.