Projects can now set a `buildvm` variable in their `config` file to
specify a unique name for their build VMs. This allows multiple
projects to have running VMs simultaneously.
If a project does not provide a name, the build VM will be called
`aimeebuild`.
Very large packages cannot be built with `PORTAGE_TMPDIR` on a tmpfs
mount, unless the VM has a tremendous amount of RAM. The performance
improvement is negligible anyway, so let's not bother.
It turns out that QEMU microvms have a very limited number of I/O ports
available for e.g. attached disks and shared filesystems. To conserve
ports, we'll use a single volume for both distfiles and binpkgs cache
directories.
In effort to support different builds of Aimee OS using the same
scripts, without necessarily having to fork this repository, the build
system now supports a `CONFIGDIR` setting. When this variable is set,
files defining the target environment, such as the lists of packages to
install, the kernel configuration, the Portage configuration, etc. are
found in the path it specifes.
The reference build, for the Home Assistant Yellow board, is configured
in the `yellow` directory. To build it, run:
```sh
CONFIGDIR=yellow ./vm-build.sh
```
This script uses the `ocivm` tool to launch a QEMU micro VM to build
the operating system. This is necessary to produce an SELinux-enabled
system, since container runtimes interfere with the SELinux policy
build and filesystem labeling processes.
Dustin