========================
Wireless drivers and HAL
========================

The wireless-radio slice of the vendor driver/HAL layer — split out from the
general HAL catalogue (:doc:`/userspace/drivers-hals`) because it belongs
next to the Bluetooth firmware/protocol pages in this section
(:doc:`bluetooth`, :doc:`bluetooth-audio-latency-bug`). Covers Bluetooth,
WLAN, and the present-but-disabled NFC/GNSS/FM/ANT+ HALs.

Everything here is from ``vendor_a.img`` (``lib/modules/``, ``bin/hw/``,
``lib64/hw/``, ``etc/vintf/manifest.xml``) read with ``7z``, cross-checked
against ``kernel_config.txt``. No code was executed.

Loadable kernel module
=======================

.. list-table::
   :header-rows: 1
   :widths: 26 74

   * - Module
     - Role / hardware
   * - ``qca_cld3_wlan.ko``
     - the WLAN driver (~10.5 MB) — loads ``wlanmdsp.mbn`` + ``bdwlan.*`` board
       data (:doc:`/userspace/firmware-blobs`), paired with the ``wifi@1.0`` HAL

HAL services and implementations
=================================

.. list-table::
   :header-rows: 1
   :widths: 26 40 34

   * - HAL
     - Implementation
     - Hardware / cross-ref
   * - ``wifi@1.0-service`` + ``hostapd`` / ``wpa_supplicant``
     - (uses ``qca_cld3_wlan.ko``)
     - WLAN (:doc:`/userspace/firmware-blobs`)
   * - ``bluetooth@1.0-service-qti``
     - ``bluetooth@1.0-impl-qti``, ``bluetooth_audio``, ``bluetooth_sar``,
       ``btconfigstore``
     - QCA BT (:doc:`bluetooth`)

The ``bluetooth_audio`` entry above is not just a static binding: static
disassembly of ``btaudio_offload_if.so`` / ``libbluetooth_audio_session_qti.so``
against the Bluetooth Mainline APEX turned up a two-bug chain — a confirmed
permanent latency-value staleness bug, plus an inferred 10⁵ unit-scaling bug
that wraps through a 16-bit field — behind a real logged symptom — see
:doc:`bluetooth-audio-latency-bug`.

Present HALs for disabled features
====================================

As with the SoC-fabric leftovers (:doc:`/soc/absent-hardware`), several radio
HALs ship from the Qualcomm/vendor reference image for features this device
does not enable — declared unavailable in
``android.hardware.onyx_unavailable_features.xml`` (:doc:`/display/stack`)
even though the HAL is on disk:

- **NFC** — ``vendor.nxp.hardware.nfc@2.0-service`` is present; NFC is declared
  unavailable.
- **GNSS/GPS** — ``gnss@2.1-service-qti`` + ``vendor.qti.gnss@4.3-impl`` present;
  ``location.gps`` declared unavailable.
- **FM radio / ANT+** — ``vendor.qti.hardware.fm@1.0-impl`` and
  ``com.dsi.ant@1.0-impl`` present; no evidence either is wired.

Their presence is confirmed on disk; the reason is most plausibly
reference-design baggage rather than something this device actually uses —
an inference from the fact that they ship unused, not confirmed from any
build note; the authoritative
"what this device actually has" signal is the unavailable-features list plus
the DTB population, not the HAL inventory.

Provenance
==========

:Source: ``artifacts/super/vendor_a.img`` — ``lib/modules/{*.ko,modules.load}``
   (module set + boot load order), ``bin/hw/*`` and ``lib64/hw/*`` (HAL
   service and implementation libraries), ``etc/vintf/manifest.xml`` (HAL
   declaration); ``artifacts/boot_a/kernel_config.txt``.
:Method: ext4 image listed/extracted read-only with ``7z``; modules counted
   from ``modules.load``; HAL from ``bin/hw`` / ``lib64/hw`` names and the
   VINTF manifest. No code executed.
:Cross-refs: :doc:`bluetooth` (BT firmware), :doc:`bluetooth-audio-latency-bug`
   (the two-bug chain behind ``bluetooth_audio``), :doc:`/userspace/firmware-blobs`
   (WLAN/BT firmware), :doc:`/userspace/drivers-hals` (the rest of the HAL/module
   catalogue), :doc:`/soc/absent-hardware` (present-but-disabled HALs generally).