feat: x86-64 live/installer ISO (MAD-846)

.github/workflows/build.yml

@@ -73,11 +73,43 @@ jobs:
             deploy/*.img.info
             deploy/*.deb
 
+  iso:
+    # The x86-64 live/installer ISO (MAD-846, ADR 0013): live-build in a
+    # Debian Trixie container, natively on an x86 runner. Same customise
+    # layer as the Pi image, so the same smoke test covers its rootfs.
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: boxd/go.mod
+
+      - name: Build ISO
+        run: make iso
+
+      - name: Smoke test
+        run: scripts/smoke-test.sh deploy/syncphony-box-*-amd64.iso
+
+      - name: Upload ISO
+        uses: actions/upload-artifact@v4
+        with:
+          name: syncphony-box-iso-${{ github.sha }}
+          compression-level: 0
+          if-no-files-found: error
+          path: |
+            deploy/*.iso
+            deploy/*.iso.sha256
+            deploy/*_amd64.deb
+
   release:
-    # Tags only: publish what the image job built and smoke-tested
-    # (MAD-809/MAD-810, ADR 0011 and 0012).
+    # Tags only: publish what the image and iso jobs built and smoke-tested
+    # (MAD-809/MAD-810/MAD-846, ADR 0011, 0012 and 0013).
     if: startsWith(github.ref, 'refs/tags/v')
-    needs: [tests, image]
+    needs: [tests, image, iso]
     runs-on: ubuntu-latest
     timeout-minutes: 30
     permissions:
@@ -93,7 +125,8 @@ jobs:
 
       - uses: actions/download-artifact@v4
         with:
-          name: syncphony-box-image-${{ github.sha }}
+          pattern: syncphony-box-*-${{ github.sha }}
+          merge-multiple: true
           path: deploy
 
       - name: Check the release inputs
@@ -111,9 +144,13 @@ jobs:
           scripts/changelog-section.sh "${VERSION}" > notes.md
           IMAGE="deploy/syncphony-box-${GITHUB_REF_NAME}-arm64.img.xz"
           DEB="deploy/syncphony-box_${VERSION}_arm64.deb"
-          ls -l "${IMAGE}" "${DEB}"
+          ISO="deploy/syncphony-box-${GITHUB_REF_NAME}-amd64.iso"
+          DEB_AMD64="deploy/syncphony-box_${VERSION}_amd64.deb"
+          ls -l "${IMAGE}" "${DEB}" "${ISO}" "${DEB_AMD64}"
           echo "IMAGE=${IMAGE}" >> "$GITHUB_ENV"
           echo "DEB=${DEB}" >> "$GITHUB_ENV"
+          echo "ISO=${ISO}" >> "$GITHUB_ENV"
+          echo "DEB_AMD64=${DEB_AMD64}" >> "$GITHUB_ENV"
 
       - uses: sigstore/cosign-installer@v3
         with:
@@ -123,7 +160,8 @@ jobs:
         run: |
           set -euo pipefail
           cd deploy
-          sha256sum "$(basename "${IMAGE}")" "$(basename "${DEB}")" > SHA256SUMS
+          sha256sum "$(basename "${IMAGE}")" "$(basename "${DEB}")" \
+            "$(basename "${ISO}")" "$(basename "${DEB_AMD64}")" > SHA256SUMS
           # Keyless: the signature binds SHA256SUMS to this workflow run at
           # this tag (Sigstore's transparency log records it).
           cosign sign-blob --yes --bundle SHA256SUMS.sigstore.json SHA256SUMS
@@ -148,6 +186,7 @@ jobs:
             --notes-file notes.md \
             --verify-tag \
             "${IMAGE}" "${IMAGE}.sha256" "${DEB}" \
+            "${ISO}" "${ISO}.sha256" "${DEB_AMD64}" \
             deploy/SHA256SUMS deploy/SHA256SUMS.sigstore.json \
             imager/os_list.json
 
@@ -170,7 +209,7 @@ jobs:
             git worktree add --orphan -b gh-pages site
           fi
 
-          scripts/apt-repo.sh site/apt "${DEB}"
+          scripts/apt-repo.sh site/apt "${DEB}" "${DEB_AMD64}"
           cp packaging/apt/syncphony-box-archive-keyring.asc site/apt/
           mkdir -p site/imager
           cp imager/os_list.json site/imager/os_list.json

.gitignore

@@ -1,4 +1,4 @@
 deploy/
 .build/
 # Built by ./build.sh into the pi-gen stage, never committed.
-stage-syncphony/00-packages/files/
+stage-syncphony/*/files/

CHANGELOG.md

@@ -8,6 +8,14 @@ Add to `## [Unreleased]` as you go; rename it when you tag.
 ## [Unreleased]
 
 ### Added
+- **The box on any x86-64 PC.** Each release also has
+  `syncphony-box-<version>-amd64.iso`, a hybrid ISO for a USB stick or
+  DVD, UEFI or legacy BIOS (Secure Boot off). Boot **Syncphony Box** to
+  run the box from the stick (a `syncphony-data` partition on the stick
+  keeps its pairing), or **Install Syncphony Box to disk** to install it,
+  with the same read-only root, `/data`, setup and nightly updates as a
+  Pi. Thermals come from the PC's thermal zones, `audio=` picks a PC's
+  HDMI/DisplayPort or analog outputs, and there's no HDMI-CEC.
 - **Releases you can flash from Raspberry Pi Imager.** A `v*` tag builds
   the image, smoke-tests it and publishes a GitHub Release with the
   `.img.xz`, its checksum, a cosign-signed `SHA256SUMS` and the notes
@@ -37,6 +45,8 @@ Add to `## [Unreleased]` as you go; rename it when you tag.
 ### Changed
 - The image is smaller: documentation, man pages and translations are
   stripped (copyright files stay).
+- The Pi image and the x86 ISO are built from one shared customisation
+  layer (`rootfs/`), so they can't drift apart.
 
 ## [0.1.0]
 

Makefile

@@ -1,8 +1,12 @@
-.PHONY: image clean test lint reset
+.PHONY: image iso clean test lint reset
 
 image:
 	./build.sh
 
+# The x86-64 live/installer ISO (MAD-846): live-build in a Debian container.
+iso:
+	./build-iso.sh
+
 test: .build/boxd
 	@command -v bats >/dev/null 2>&1 || { echo "bats is required (e.g. apt install bats)"; exit 1; }
 	@command -v go >/dev/null 2>&1 || { echo "go is required (https://go.dev/dl/)"; exit 1; }
@@ -28,5 +32,5 @@ reset: .build/boxd
 
 clean:
 	rm -rf deploy .build
-	rm -rf stage-syncphony/00-packages/files
+	rm -rf stage-syncphony/*/files
 	-docker rm -v pigen_work >/dev/null 2>&1 || true

README.md

@@ -4,7 +4,9 @@ A flashable Raspberry Pi image that turns a Pi plugged into a TV into the
 room's big screen and its speaker — a kiosk for an existing
 [Syncphony](https://github.com/madeofpendletonwool/Syncphony) server. Flash
 the image with [Raspberry Pi Imager](https://www.raspberrypi.com/software/),
-plug the Pi into the TV, and it boots straight into the room.
+plug the Pi into the TV, and it boots straight into the room. An old PC or
+a mini-PC works too: boot the [x86-64 ISO](#on-a-pc-x86-64) from a USB
+stick and install it.
 
 The box is **client only**: it runs no Syncphony server. Point it at yours.
 
@@ -68,11 +70,52 @@ sha256sum --check --ignore-missing SHA256SUMS
 tagged source. (Imager checks the image against the listing's SHA-256 on
 its own while writing.)
 
+### On a PC (x86-64)
+
+Any 64-bit PC or mini-PC with 2 GB of RAM and a disk of 8 GB or more
+([ADR 0013](docs/adr/0013-x86-iso.md)). Turn **Secure Boot off** in the
+firmware settings; UEFI and legacy BIOS both work.
+
+1. **Download** `syncphony-box-<version>-amd64.iso` from the
+   [release](https://github.com/madeofpendletonwool/syncphony-box/releases)
+   and write it to a USB stick (Imager's **Use custom**, balenaEtcher,
+   or `sudo dd if=syncphony-box-<version>-amd64.iso of=/dev/sdX bs=4M
+   conv=fsync`). It's a hybrid ISO, so a DVD works too.
+2. **Boot the PC from the stick**, plugged into the TV. The menu has two
+   entries:
+   - **Syncphony Box** runs the box from the stick, with nothing
+     installed. Good for trying it. Its changes live in RAM, so it
+     forgets its setup and pairing at power-off, unless the stick has a
+     `syncphony-data` partition (below).
+   - **Install Syncphony Box to disk** erases a disk you pick and installs
+     the box on it. It offers an optional admin user (sudo, for SSH and
+     maintenance; a PC has no Imager to make one). When it's done, remove
+     the stick; the PC restarts into the box.
+3. **Point it at your server and pair**, as in steps 5 and 6 above. The
+   setup QR, the hotspot, updates and the read-only root all work as on
+   a Pi. There is no HDMI-CEC: most PC graphics can't send it.
+
+**Keeping a live stick's pairing.** Add a partition labelled
+`syncphony-data` to the stick, in the free space after the ISO, and the
+live box keeps its setup and pairing there:
+
+```sh
+# /dev/sdX is the stick with the ISO already written to it.
+echo ',,L' | sudo sfdisk --append /dev/sdX
+sudo mkfs.ext4 -L syncphony-data /dev/sdX4   # the ISO has 3; this is the 4th
+```
+
+Remove the stick before booting an installed box: both would offer a
+`syncphony-data` partition.
+
 ## Supported hardware
 
 - Raspberry Pi 4 or Pi 5, 2 GB RAM or more
 - 16 GB+ SD card
-- arm64 only. Pi 3, Pi Zero 2 W and armhf are not supported.
+- On a Pi, arm64 only. Pi 3, Pi Zero 2 W and armhf are not supported.
+- Or an x86-64 PC: 2 GB RAM, an 8 GB+ disk, Secure Boot off
+  ([On a PC](#on-a-pc-x86-64)). The ISO carries firmware for Intel and
+  AMD graphics; NVIDIA graphics are untested.
 - A case with a heatsink or a fan. A long party with the visualizer on
   warms a Pi in a closed case past its soft temperature limit, and the
   firmware silently halves the CPU first (the box logs temperature and
@@ -100,6 +143,13 @@ The result lands in `deploy/`:
   package. The image installs it, and boxes update to newer ones from the
   apt repo.
 
+`make iso` builds the x86-64 ISO the same way, with Debian's live-build
+in a privileged `debian:trixie` container (native on an x86 host,
+emulated and slow on an arm64 one): `syncphony-box-<version>-amd64.iso`,
+its `.sha256`, and the `_amd64.deb`. Both images run the same
+customisation (`rootfs/customise.sh`) inside their build chroots, so a
+change to the box lands in both ([ADR 0013](docs/adr/0013-x86-iso.md)).
+
 `make clean` removes build output and the leftover pi-gen build container.
 
 `make test` runs the unit tests — the bats suite (`tests/`) that pins the
@@ -117,8 +167,11 @@ loop-mounts the built image and checks packages, enabled units, the locked
 first user, the first-boot seed files, the kiosk session, the boot
 config file, the audio stack, boxd, and the read-only-root layout: three
 partitions, the overlay wired into the initramfs, and every persistent
-path on /data), and uploads the image as a workflow artifact. Pushing a
-`v*` tag also releases it; see [docs/releasing.md](docs/releasing.md).
+path on /data), and uploads the image as a workflow artifact. An x86
+runner builds the ISO alongside it and runs the same smoke test against
+the ISO's root filesystem, plus its boot menu (UEFI and BIOS), its
+initramfs and the installer. Pushing a `v*` tag releases both; see
+[docs/releasing.md](docs/releasing.md).
 
 ## boxd
 
@@ -386,11 +439,19 @@ the box from booting; bad values are logged and fall back to defaults.
 | `audio` | `hdmi`, `hdmi2`, `analog`, `usb` | `hdmi` | where the sound goes (`analog` is the Pi 4's jack — a Pi 5 has none; use `usb` for a DAC) |
 | `resolution` | e.g. `1920x1080@60` | auto | forces the HDMI mode (takes a reboot; the box reboots once on its own) |
 | `rotate` | `0`, `90`, `180`, `270` | `0` | rotates the screen (takes a reboot) |
-| `cec` | `on`, `off` | `on` | switch the TV's input when music starts (HDMI-CEC; the remote's keys drive the box too — [docs/hardware.md](docs/hardware.md) for the TV matrix) |
+| `cec` | `on`, `off` | `on` | switch the TV's input when music starts (HDMI-CEC; the remote's keys drive the box too — [docs/hardware.md](docs/hardware.md) for the TV matrix). Pi only |
 | `cec_standby` | `on`, `off` | `off` | put the TV in standby once the room has been idle (only ever a TV the box switched on itself) |
 | `cec_standby_minutes` | `1`–`240` | `30` | how many idle minutes before that standby |
 | `auto_update` | `on`, `off` | `on` | install updates every night around 04:00 ([Updates](#updates)) |
 
+On a PC box, `syncphony.txt` is on the `SB-BOOT` partition (the EFI
+system partition, also at `/boot/firmware`), and `resolution`/`rotate`
+go into `/boot/firmware/cmdline.cfg`, which GRUB reads. `audio=hdmi` and
+`hdmi2` are the first and second HDMI/DisplayPort outputs; `analog` is
+the headphone/line-out jack. In the live session (from the USB stick)
+the file is in RAM, or on the stick's `syncphony-data` partition, and
+`resolution`/`rotate` don't apply.
+
 On every boot, `syncphony-box-config.service` runs `boxd config apply`:
 it parses the file into `config.env` (kept on `/data`; `/etc/syncphony-box/config.env`
 is a symlink to it) before the kiosk starts; `resolution` and `rotate`
@@ -490,19 +551,27 @@ has its own page: [docs/testing.md](docs/testing.md).
 
 ```
 pi-gen/               pi-gen submodule (pinned, never edited)
+rootfs/               the shared customise layer both images run inside
+                      their chroot: package lists, the .deb, the steps
+                      (ADR 0013)
 packaging/root/       every file of the syncphony-box .deb, laid out as
                       it installs (units, kiosk wrapper, scripts, ...)
 packaging/debian/     the .deb's control template and postinst
 packaging/apt/        the updater's apt source and the repo's public key
 packaging/imager/     the Imager listing's icon
-stage-syncphony/      custom pi-gen stage: installs the .deb, then the
-                      image-only changes (cmdline, fstab, /data links, ...)
+stage-syncphony/      custom pi-gen stage: runs rootfs/customise.sh, then
+                      the Pi's boot partition (cmdline, config.txt, ...)
+x86/live/             live-build config and hooks for the x86 ISO
+x86/root/             the ISO's own files: the installer, its units and
+                      GRUB templates, the live session's /boot/firmware
 boxd/                 the box's Go helper daemon (bridge, config, screens,
                       watchdogs, CEC, Wi-Fi setup hotspot)
 config                pi-gen build configuration
 build.sh              wraps pi-gen's build-docker.sh (builds boxd and the
                       .deb first, then appends the /data partition)
-Makefile              make image / make test / make lint / make clean
+build-iso.sh          builds the x86 ISO with live-build in a container
+Makefile              make image / make iso / make test / make lint /
+                      make clean
 scripts/add-data-partition.sh  the /data partition post-export step
 scripts/smoke-test.sh no-hardware image checks (used by CI)
 scripts/build-deb.sh  builds the syncphony-box .deb