Why Mountain Lion Deserves Its Own Wireless Guide

Why Mountain Lion Deserves Its Own Wireless Guide

macOS 10.8 Mountain Lion occupies an odd spot in the Hackintosh timeline. It shipped with a revised IO80211Family kext that dropped support for several older Broadcom and Atheros chipsets that worked perfectly under Lion (10.7). At the same time, it predates the strict hardware whitelisting that Apple introduced in later versions. For a user building a retro Hackintosh around a Sandy Bridge or Ivy Bridge platform, Mountain Lion can be both the most practical and the most frustrating macOS version to get wirelessly connected — if you pick the wrong card. Here's a chipset-by-chipset breakdown of what actually works, what requires patching, and what will never see a Wi-Fi menu.

Native Support: The Short List

Mountain Lion’s IO80211Family.kext (version 5.0.0) retains native drivers for a handful of AirPort Extreme chipsets. These cards appear as built-in Wi-Fi with no extra kexts or injectors:

• Atheros AR9280 (PCIe, 2.4/5 GHz, 802.11a/b/g/n) — the most reliable choice. Works out of the box with full signal strength reporting and no sleep wake instability.
• Atheros AR9285 (PCIe, 2.4 GHz only) — works natively but limited to 2.4 GHz. Useful for mini-PCIe slots in older laptops, but avoid if you need 5 GHz.
• Broadcom BCM4322 (AirPort Extreme BCM94322) — tested with Lenovo and Dell OEM cards. Native support in Mountain Lion, but only if the card’s subsystem ID is Apple-compatible or spoofed. Realtek-based BCM4322 variants may fail.
• Broadcom BCM94360 (PCIe, 802.11a/b/g/n) — the 3×3 MIMO version. Works natively, but requires a compatible PCIe adapter. Some clones with incorrect VID/PID may need a device-id injection.

All of these cards will appear in System Information under Network as “Wi-Fi” with the driver listed as “com.apple.driver.AirPort.Atheros” or “AirPort.Brcm4360”. No extra kexts are required.

Cards That Work with a Patch (and Their Caveats)

A few chipsets that shipped with Lion drivers were removed from Mountain Lion’s kext but can be re-enabled with a simple plist edit or a small injector kext. This is not a hack — it is restoring a driver that Apple left in the bundle but disabled at the I/O Kit level.

Atheros AR9287

Present in many Dell and HP laptops from 2010–2011. The AR9287 uses the same Atheros driver family as the AR9280, but Mountain Lion’s IO80211Family.kext does not list its PCI device ID (0x002E). To enable it, add the device ID to the AirPortAtheros40.kext/Contents/Info.plist under IOPCIMatch. After a kext cache rebuild and reboot, the card appears as a supported AirPort. No side effects reported.

Broadcom BCM43224

Found in some early 2011 MacBook Pro models — ironically, Apple shipped this chip in their own hardware but later dropped it from Mountain Lion’s driver list. The BCM43224 uses the AirPortBrcm4331 driver. To enable, add the device ID (0x4353) to the same kext’s Info.plist. Some users report intermittent Bluetooth coexistence issues on 2.4 GHz bands; switching to 5 GHz resolves it.

Broadcom BCM94331

This is a rare PCIe card used in some Mac Pros. It works in Mountain Lion with the same patch as the BCM43224, but only if the card is recognised as a third-party device. If the system sees it as an Apple-branded card, it may trigger a kernel panic on wake from sleep. The workaround is to use a SSDT that renames the device to AirPort_Brcm43xx and disables the power management. This is covered in our Creating a Custom SSDT for Legacy Hackintosh LPC, SMBus, and GPIO Controllers guide, though the focus there is on LPC, the same methodology applies to AirPort power control.

Chipsets That Will Never Work (and Why)

Some cards are frequently suggested for older versions but fail under Mountain Lion:

If you own any of these, the only reliable option is a USB Wi-Fi adapter with a compatible chipset (see below).

USB Wi-Fi Adapters: A Cautious Approach

For users who cannot replace an internal card, USB adapters offer a fallback, but they come with caveats. Mountain Lion’s IOUSBFamily is less tolerant of non-standard configurations than later versions. The only chipset families with reliable, free kexts are:

• Ralink RT2870/RT3070 — The open-source rt2800usb driver works in Mountain Lion, but only with adapters that use the Ralink reference design. Many cheap clones use a different USB ID and require manual editing of the Info.plist. Maximum throughput: 150 Mbps on 2.4 GHz.
• Realtek RTL8187L — The VoodooWiFi kext (a fork of the Realtek Linux driver) supports this old chipset. It works for basic connectivity but drops connection under load. Do not use for file transfers.
• Zydas ZD1211 — The zd1211.kext from the Zydas project works in 32-bit kernel mode only. Mountain Lion boots 64-bit by default, so you must force a 32-bit kernel with arch=i386 boot argument, which breaks many other kexts. Not recommended.

All USB Wi-Fi adapters in Mountain Lion lose connection after sleep unless you unplug and replug. This is a known limitation of the USB stack in 10.8. Do not rely on them for a “set it and forget it” build.

Configuration Steps: From Installation to Verification

After installing a supported card, follow these steps to ensure full functionality:

1. Check device ID: Run ioreg -l | grep -i "IO80211" in Terminal. If the card is not listed, the driver is not loaded.
2. Inject device ID (if needed): Edit the Info.plist inside /System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AirPortAtheros40.kext (or AirPortBrcm4331.kext). Add your card’s PCI device ID to the IOPCIMatch array. Example: <string>0x002E168C</string> for AR9287.
3. Rebuild kext cache: sudo touch /System/Library/Extensions && sudo kextcache -u / && sudo reboot.
4. Verify subsystem: Open System Information → Network → Wi-Fi. If the card is listed as “Third-Party” but the driver is “AirPort” (not “AppleAirPort”), it will work. If it shows “No Wi-Fi Hardware Installed”, the patch failed.
5. Test sleep/wake: Put the system to sleep and wake it. Check that Wi-Fi reconnects. If it does not, add darkwake=0 to boot-args, or disable wake on Wi-Fi in Energy Saver.

Risks and Backup Practices

Editing system kexts in /System/Library/Extensions is inherently risky. A wrong plist change can cause a kernel panic at boot. Always create a backup of the original kext before modifying, and keep a bootable USB installer with the same macOS version ready to repair. If you use a patched kext, reapply it after every macOS update (including security updates, which Mountain Lion no longer receives, but point releases like 10.8.5 may still appear).

For users who prefer a less invasive approach, consider using a supported native card rather than patching. The AR9280 can be found for under $10 on the used market, and it eliminates every driver-related headache.

Final Check: Ethernet as a Fallback

Before committing to a wireless solution, ensure your motherboard’s Ethernet controller works natively in Mountain Lion. If you end up with a problematic Wi-Fi card, you can always fall back to wired networking while debugging. Most Intel ICH10R, RTL8111, and Realtek 8168 chips work with the built-in drivers. The combination of a working Ethernet port and a native AR9280 Wi-Fi card makes for the most stable Mountain Lion Hackintosh you can build today.