Ath12kWifi

Start with the adaptation procedure for board inputs, source changes, build integration and verification order.

Ath12kWifi implements an ath12k-based Wi-Fi stack with PCI, MHI, QRTR, and board-supplied interfaces. The source includes QCC2072, QCN9274, and WCN7850 hardware definitions.

Field	Value
Repository	UniXNU/Ath12kWifi
Function	ath12k Wi-Fi transport and driver integration
Board inputs	PCI access, interrupts, firmware and board callbacks
Hardware verification	Record device-specific results in the device page

Read the component README and nw_board interfaces before selecting it. The catalog records its source revision, OS requirements, build command, and outputs. Use the component's host checks and the board's network verification procedure.

State on sheng (WCN7850)

Ath12kWifi compiles the Linux ath12k, MHI and QMI sources over its own compatibility layer (shim/) and adds a station layer (src/nw_sta.c: scan, join, WPA2-Personal, data path). The board interface is include/nw_abi.h. tools/prepare.sh fetches and patches the driver sources. UniXNU-sheng powers the chip, trains PCIe0 and attaches the module to iPadOS as en0 (package/WifiProbe.cpp: power, PCIe0, firmware, DMA, MSI, module thread; package/WifiNet.cpp: en0 and the system's Wi-Fi requests).

Status: joins WPA2-Personal, gets DHCP, Safari loads pages. Throughput is low.

Boot argument	Meaning
`sheng-wifi=5`	Start Wi-Fi. Without it the module never runs.
`sheng-wifi-aj=0`	No join at boot; Settings joins.

iPadOS 27 service startup

The sheng board DTS exports WCN7850 as /arm-io/wlan using unixnu,adt-name = "wlan". The stock 24A446 com.apple.wifid job checks _LimitLoadToDeviceTree before launchd loads it. Without a matching node, the kernel's join.txt path can still connect and exchange packets while Settings shows an empty Wi-Fi page and cannot enable the switch. /chosen/mac-address-wifi0 and the IOService network objects do not satisfy this device-tree condition.

The 27 payload defaults include sheng-wifi=5. After changing the DTS, rebuild the payload and boot image, then inspect the ADT inside the image. Host checks confirm the node satisfies the startup condition; starting wifid, enabling the Settings switch and scanning still require a device test. Remove sheng-autoreset from a manual test image's boot arguments.

Facts

Each of the six PMU rails needs RPMh mode, voltage and enable requests. Without the mode request two rails stay off and the link never trains.
PCIe0 reaches L0 at Gen2 x1. The endpoint reads 17cb:1107.
Firmware c2-00259 hangs in its demand pager. Firmware c7-00108 works and is used.
The firmware reports a zero MAC. The board supplies one made from the chip ID.
For development the firmware is read from the spare oops partition.
6 GHz is left out of the scan: its 59 passive channels took most of an 11 s scan.
A firmware beacon miss is ignored while frames still arrive within 5 s.
Join and the four-way handshake complete in about 100 ms.
Without HT and VHT in the association the link ran phymode 11g, about 20 Mbit/s. With the access point's width (80 MHz) but this radio's capability in the peer entry, 596 of 863 transmitted frames were never acknowledged. With the access point's own capability almost every frame is acknowledged.
The access point sends some frames at VHT MCS 10/11. The driver drops them (about 70 per run).
With the chip's MSIs on an unwatched page, a thread polled the module every 1 ms. Routing them through PCIe0's own MSI receiver to SPI 141 lets the thread sleep between interrupts: 16 vectors, a few tens of interrupts per second when idle.
Speed test (5 GHz, 80 MHz, -73 dBm): about 12 Mbit/s down, 24 Mbit/s up, under 1 % transmit loss. DHCP gives an address within 31 s of boot.
The system Wi-Fi daemon takes over from the boot join and scans until a manual join. The system cannot store the network password (keychain error -25291).
The hot processes are coreduetd and one other system process, not the Wi-Fi thread.

Guesses

The throughput limit is in the receive path to ifnet_input (one copied frame per call) or in the TCP window.
The daemon leaves the boot join because the network is not stored as known.
The heat comes from system daemons and the GPU path.

Plan

Count frames per second at each receive stage during a speed test.
Pass received frames to the stack in chains, without the extra copy.
Load the firmware from files instead of oops, then restore oops.
Later: 6 GHz, Wi-Fi 6/7 capability, power save.

Build

unixnu build kernel compiles the module with UniXNU-sheng's scripts/build-ath12k-wifi.py, from drivers/Ath12kWifi in UniXNU-sheng or ATH12K_WIFI_DIR.

4.8 KiB Raw Blame History