LineageOS 18.1 (Android 11) — Huawei MediaPad M3 Lite 10 (bach)

Unofficial Android 11 port for bach (BAH-AL00 / L01 / L09 / W09), built on surdu_petru's LineageOS 17.1 (Huawei-Dev). Branch: eleven.

Developer-stage port. Boots and runs as a daily driver; all three camera functions work after a small set of /vendor overlays — read How it installs and docs/CAMERA.md before flashing.

Spec
SoC	Qualcomm MSM8937, Snapdragon 435 (octa-core A53) / Adreno 505
Display	10.1″ IPS, 1200×1920 (16:10)
RAM/Storage	3/4 GB · 32/64 GB + microSD
Cameras	8 MP rear (AF, 1080p30) · 8 MP front
Battery	6660 mAh

How it installs — system + boot only

This tree builds system + boot only. It deliberately keeps the device's existing LineageOS 17.1 /vendor (A10 blobs, VNDK-29) and 3.18-kernel userspace untouched, so it is flashed over an existing LOS 17.1 install (surdu_petru's) — not standalone. There is no vendor image and no blob extraction here: the A10 vendor is reused, with a few A11-compat overlays (see camera notes). Hence BoardConfig.mk keeps PRODUCT_EXTRA_VNDK_VERSIONS := 29 and the kernel ships prebuilt.

Status

Area	State
Boot / system / UI	stable daily driver
Cameras (rear + front)	live preview + 8 MP stills + 1080p/30 video, via the bundled Open Camera (needs the kernel fix + stats-blob patch + /vendor overlays below)
Wi-Fi / Bluetooth / sensors / touch	working
Audio	working. Speaker: a clean flash has the raw harsh-at-high-volume treble — the de-harsh fix is a separate rootless app (BachSpeakerEQ), not yet bundled in the ROM, so it must be installed and is wiped by a clean reflash.

Caveats

• SELinux is enforcing since the 20260618 release (androidboot.selinux=enforcing). Earlier builds ran permissive as a bring-up shortcut. Two device allows carry the reused A10 vendor: vndservicemanager → cameraserver (binder) and the Huawei sensor HAL's oeminfo socket.
• The camera /vendor overlays are bundled since 20260618 — the release is a self-contained system + boot + vendor zip, clean-installable from a full wipe. No hand-application needed.
• TWRP note: the system partition mounts at /system_root/system, not /system.

Build

1. Init + sync a LineageOS 18.1 tree, then add .repo/local_manifests/bach.xml:

   <?xml version="1.0" encoding="UTF-8"?>
   <manifest>
     <remote name="superheher" fetch="https://github.com/superheher" />
     <project name="android_device_huawei_bach" path="device/huawei/bach" remote="superheher" revision="eleven" />
     <project name="android_kernel_huawei_bach" path="kernel/huawei/bach" remote="superheher" revision="eleven-cve" />
   </manifest>

   then repo sync.

2. source build/envsetup.sh && breakfast bach && mka bacon

   • Kernel ships prebuilt as prebuilt/Image.gz-dtb (the verified v2fix build) via TARGET_PREBUILT_KERNEL. To build from source instead, drop that line from BoardConfig.mk (source = the kernel repo above; TARGET_KERNEL_CONFIG := bach_defconfig).

   Known issue — the from-source system image does not boot. Since June 2026 a build from this tree hangs on the boot splash, in both permissive and enforcing variants. The boot ramdisk is byte-identical to the last known-good build and the vendor is unchanged, so the regression is in system; the cause is still unidentified and a full m clobber rebuild is the next experiment. Published releases are therefore hand-assembled from the last system image proven to boot — see publish*/BUILD_PROVENANCE.md. A consequence worth knowing: system.prop cannot reach a released device, so its properties are routed through /vendor/build.prop instead (both files deliver every namespace; /vendor wins duplicates).

3. Flash the release zip in TWRP — it is self-contained (system + boot + vendor) and installs over an existing build keeping /data, or from a full wipe. The camera /vendor overlays and the stats-blob patch are already inside it; docs/CAMERA.md documents what they are and why.

Camera (the hard part)

App vs. stack: the fixes here are at the camera stack level (kernel + HAL/daemon), so any app benefits. But the stock LineageOS camera app is too strict for this old HAL — it won't even preview — so Open Camera (FOSS) is bundled as the camera app and replaces the stock one (via LOCAL_OVERRIDES_PACKAGES), so it's the sole, default camera.

The closed A8.1/A10 camera stack runs under A11 strict-Treble (on the reused A10 /vendor) via a chain of /vendor overlays plus two original fixes. Full write-up, exact files and root-cause in docs/CAMERA.md. In short:

• A11-compat /vendor overlays: a minimal stub libandroid.so, VNDK-29 camera HIDL libs copied into /vendor/lib, the A10 vendor.qti.hardware.camera.device@1.0.so, VNDK-29 libgui / kept libcrypto.
• Kernel fix isp: req_frm_ver2 (kernel repo) — fixes still-capture (was green/empty: "Invalid bufq").
• Stats-blob 2-byte patch (patch-blobs.sh) — neutralizes an AEC use-after-free that SIGSEGV-crashed the camera daemon in video mode (froze preview, broke recording). Enables 1080p video + reliable preview.
• (Optional) patches/frameworks_av-bach-jpeg-shim.patch — capture-reliability shim; not required once the kernel fix is in.

Credits

surdu_petru / Huawei-Dev — original bach bring-up (LOS 14 → 17.1). This Android 11 port stands on that work.