quine-linux/README.md

# quine-linux

Quine distro of Linux based on uBlue Aurora

## Building

`Containerfile` builds a custom bootc image on top of `ghcr.io/ublue-os/aurora:stable`,
layering in everything under `overlay/`, plus a `kmod-builder` stage that
compiles the CS8409 mic-fix kernel module (see
[Hardware-specific patches](#hardware-specific-patches) below).

[`Taskfile.yml`](Taskfile.yml) (requires [`task`](https://taskfile.dev)) is
the supported way to drive all of this — run `task` with no arguments to
list what's available. Notably:

- `task build-image` — builds the image locally (`podman build`, as root).
- `task build-iso` — builds a bootable install ISO from that image via
  `bootc-image-builder`, landing in `output/bootiso/install.iso`.
- `task test:stage` / `task test:boot` — stage the locally-built image as
  this machine's next boot target (`bootc switch`), optionally rebooting
  into it immediately. The fast way to test a change — especially the
  kernel module — against the real running system, without building an ISO
  or reinstalling anything.
- `task revert` — rolls back to the previously-booted deployment and
  reboots, undoing a `test:boot` switch (or any other deployment change) if
  something's wrong.

Equivalently, by hand:

```sh
podman build -t quine-linux -f Containerfile .
```

An ISO can then be generated from the built image with `bootc-image-builder`.

## overlay/

Files here mirror their path on the root filesystem and are baked into the
image via `COPY overlay/ /` in the Containerfile.

- `overlay/etc/...` — local/admin config. On the ostree-based image, content
  shipped here becomes the default `/etc` and is still locally overridable
  (3-way merged on upgrade), same as any package-installed `/etc` file.
- `overlay/usr/lib/systemd/...` — vendor-shipped units. `/usr` is replaced
  wholesale on each image build/upgrade, so anything here always matches the
  image and isn't meant to be hand-edited on a running system.

### overlay/etc/gitconfig

System-wide git config so every user on the box gets `main` as the default
init branch, not `master`.

### overlay/etc/systemd/system/rpm-ostree-cleanup.{service,timer}

Weekly, runs as root via systemd (not cron/sudoers): `rpm-ostree cleanup -rb`
(drops rollback deployment and any pending deployment). Enabled at build time
via `RUN systemctl enable` in the Containerfile.

### overlay/etc/systemd/journald.conf.d/size-cap.conf

Continuous 500M journal retention cap instead of a periodic vacuum job.

### overlay/usr/lib/systemd/user/disk-cleanup.{service,timer}

Weekly, runs as the user, no privilege needed: `podman system prune -af`,
`flatpak uninstall --unused -y`, clears `~/.cache`. Auto-enabled for every
user via `overlay/usr/lib/systemd/user-preset/90-quine-linux.preset` — no
manual `systemctl --user enable` needed.

### overlay/etc/systemd/system/cs8409-intmike-power-fixup.service

Hardware-specific fixup for the iMac19,2 internal mic (see below).

## Hardware-specific patches

`docs/` and `patches/` hold write-ups and out-of-tree kernel module patches
for hardware quirks on the machines this image runs on, that don't fit
anywhere else in this repo:

- [`docs/imac19-2-mic-fix.md`](docs/imac19-2-mic-fix.md) — the internal mic
  on iMac19,2 capturing near-silence despite maxed gain; root cause, fix,
  and current verification status.
- `patches/snd-hda-codec-cs8409/` — the vendored driver source and patch
  backing that fix, built into `Containerfile`'s `kmod-builder` stage.