https://github.com/petronijus/nexusq-reloaded
postmarketOS port of the Google Nexus Q (steelhead) on a mainline Linux 6.12 kernel — TI OMAP4460
https://github.com/petronijus/nexusq-reloaded
arm device-port linux-kernel mainline-linux nexus-q omap4 postmarketos
Last synced: about 17 hours ago
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postmarketOS port of the Google Nexus Q (steelhead) on a mainline Linux 6.12 kernel — TI OMAP4460
- Host: GitHub
- URL: https://github.com/petronijus/nexusq-reloaded
- Owner: petronijus
- License: gpl-2.0
- Created: 2026-02-25T20:07:29.000Z (4 months ago)
- Default Branch: main
- Last Pushed: 2026-06-19T17:22:45.000Z (10 days ago)
- Last Synced: 2026-06-19T17:33:16.231Z (10 days ago)
- Topics: arm, device-port, linux-kernel, mainline-linux, nexus-q, omap4, postmarketos
- Language: Shell
- Size: 1.1 MB
- Stars: 1
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Nexus Q Reloaded -- postmarketOS Port
Port of the Google Nexus Q (codename **steelhead**) to postmarketOS using a
mainline Linux 6.12 LTS kernel.
## Hardware
| Component | Chip | Driver | Bus |
|-----------|------|--------|-----|
| SoC | TI OMAP4460 (Cortex-A9 x2) | omap4 | - |
| Audio Codec | TI TWL6040 | snd-soc-omap-abe-twl6040 | McPDM (I2C1) |
| Audio Amp | TI TAS5713 25W Class-D | snd-soc-tas571x | McBSP2 (I2C4) |
| WiFi | Broadcom BCM4330 | brcmfmac | SDIO (MMC5) |
| Bluetooth | Broadcom BCM4330 | hci_bcm | UART2 |
| NFC | NXP PN544 | pn544_i2c | I2C3 |
| Ethernet | SMSC LAN9500A | smsc95xx | USB EHCI |
| HDMI | OMAP4 DSS + TPD12S015A | omapdrm | DSS |
| LEDs | AVR MCU + LP5523 | leds-lp5523 | I2C2 |
| PMIC | TI TWL6030 | twl-core | I2C1 |
## Status
**postmarketOS (systemd) boots; the device is daily-usable.** SSH over USB gadget
and WiFi (BCM4330), HDMI desktop, TAS5713 amp, LED ring + rotary keys, and a full
host-built rootfs. Since the 2026-06-10 snapshot below, several "dead" verdicts were
overturned:
- **Dual-core SMP works** (since v1.2.0; re-confirmed `nproc=2` on 2026-06-28) —
the old "single-core, SMP disabled" status is obsolete.
- **CPU frequency scaling 350→1200 MHz** (v1.4.0), governor `conservative`.
- **On-board Ethernet (LAN9500A) is NOT dead hardware** — fixed in v1.1.0/v1.3.0;
currently **down again** on cpufreq builds (a v1.4.0 boot-timing regression, fix
tracked for 1.4.1), not a hardware fault.
- The shipping kernel is built with **GCC 15.2** (Alpine, via pmbootstrap) and
boots — the historical "GCC 13.3.Rel1 only" constraint applied to an early
hand-cross-compiled build, not this path.
- **armv7 python3 works on the device (v1.6.0, flash-verified).** The long-standing
crash (`python3 -S -c ''` → rc 139 in `Py_Initialize`, taking down `onboard` /
`blueman` / `sleep-inhibitor` / `gdb`) was a **flash bug, not a build bug**:
`raw2simg.py` emitted all-zero blocks as `DONT_CARE`, which the Nexus Q's non-erasing
U-Boot left as **stale eMMC data**, re-corrupting libpython's should-be-zero regions
on-device — fixed by writing a **byte-exact all-RAW sparse**. v1.6.0 ships a plain
default-linker (bfd) `python3` rebuild that supersedes Alpine's broken `-r2`, with a
build-integrity gate (`scripts/verify-libpython-clean.py`) + ship gate kept as a
safety net. (A qemu-user build-corruption theory and a gold-linker workaround were
tried and **dropped as unnecessary** — 6/6 default-linker builds were gate-clean.)
Verified on a fresh flash (no live-patch): `libpython3.14.so.1.0` md5
`79a0d4ace1358bb2d94c8a4d72479da9`, `python3` rc 0. See `CHANGELOG.md` and
`docs/2026-06-28-session-findings.md`.
See `CHANGELOG.md` for the per-milestone record and `HANDOFF.md` for technical
notes and root-cause analysis.
See `PLAN.md` for the hardware status map and the prioritized roadmap
(TAS5713 amplifier first).
## Quick Start
```bash
# Build inside Docker
./docker-build.sh
# Or: build boot image manually (requires arm-none-eabi-gcc cross compiler)
# See docker-build.sh for the full build procedure
```
## Project Structure
```
kernel/
dts/omap4-steelhead.dts Device tree source
configs/steelhead_defconfig Kernel configuration
patches/0001-*.patch TAS5713 driver support
patches/0002-*.patch TAS5713 DT binding
patches/0003-*.patch Steelhead DTS in kernel tree
pmos/
device-google-steelhead/ postmarketOS device package
linux-google-steelhead/ postmarketOS kernel package
firmware-google-steelhead/ BCM4330 firmware package
build-and-flash.sh Automated build and flash script
```
## Flashing
The Nexus Q has hardware-triggered fastboot mode (cover mute LED during
power-on). The device is **unbrickable** as long as the `bootloader`
partition is never overwritten.
### Partition Layout
| Partition | Size | Usage |
|-----------|------|-------|
| boot | 8 MB | Kernel + embedded initramfs + DTB (6.7 MB fits) |
| system | 1 GB | Not used (too small for rootfs) |
| userdata | 13 GB | **Rootfs target** |
### Flash Commands
```bash
# Flash kernel to boot partition (ramdisk-less, must fit the 8 MB boot partition):
fastboot flash boot output/nexusq-boot-v1.6.0.img
# Flash rootfs to userdata partition. The -S 100M chunking is REQUIRED: the 2012
# U-Boot has a ~150 MB download buffer and fails SILENTLY on a larger blob.
# The v1.6.0 sparse is all-RAW (byte-exact) -- U-Boot never erases userdata, so the
# image must write every block (zeros included), not skip them as DONT_CARE.
fastboot -S 100M flash userdata output/nexusq-rootfs-v1.6.0-sparse.img
# Then power-cycle WITHOUT holding mute sensor to boot normally.
```
**IMPORTANT:**
- Always do a **full power cycle** (unplug power) between flash operations
- **Do NOT use `fastboot boot`** (RAM boot) -- it is unreliable on this U-Boot
- NEVER flash the `bootloader` partition
## Testing Pipeline
1. `make dtbs_check` -- validate device tree
2. `pmbootstrap kconfig check` -- validate kernel config
3. `pmbootstrap build` -- cross-compile
4. `pmbootstrap qemu` -- QEMU boot test (vexpress-a9)
5. `fastboot flash boot nexusq-boot-v*.img` -- flash kernel (ramdisk-less, <=8 MB)
6. `fastboot -S 100M flash userdata nexusq-rootfs-v*-sparse.img` -- flash rootfs
## Releases
Versioning is tag-only (milestone-based). Images are built locally (the kernel
and rootfs aren't built in GitHub CI) and attached to the GitHub release:
- `nexusq-boot-vX.Y.Z.img` -- kernel + initramfs boot image
- `nexusq-rootfs-vX.Y.Z-sparse.img` -- postmarketOS rootfs (Android sparse)
End-user flashing is in [INSTALL.md](INSTALL.md); build steps in `HANDOFF.md`;
version history in [CHANGELOG.md](CHANGELOG.md).
## License
[GPL-2.0](LICENSE) -- this repository carries Linux kernel patches, a device
tree and a defconfig, which are derivative works of the Linux kernel (GPLv2).