Installing

Installing a prebuilt ASFireWire build (testers)

Note

These instructions track the latest release. If you are installing an older build and something here does not match, check the release notes for that tag — the procedure can change between versions.

Tagged releases attach a prebuilt ASFW.app. This build is ad-hoc signed and NOT notarized, so it can only be loaded on a machine with System Integrity Protection (SIP) disabled. It is intended for experimental testing only — not general use.

To build and sign it yourself instead, see Building and Signing.

Warning

These steps disable SIP, which lowers your Mac's security system-wide. Only do this on a machine you are comfortable using for testing, and re-enable SIP (csrutil enable) when you are done. The build is unsigned/un-notarized and provided as-is; run it only if you understand and accept that.

Caution

Uninstall the extension before re-enabling SIP. With SIP back on, AMFI refuses to launch the ad-hoc-signed dext at every boot. That is expected to be a silent no-load, but it has not been verified on hardware with SIP enabled — don't leave the extension installed in a state where it can never launch.

Recovery, should a boot problem ever occur: Recovery → csrutil disable → boot → systemextensionsctl uninstall - net.mrmidi.ASFW.ASFWDriver → csrutil enable.

Requirements

• An Apple Silicon Mac running macOS 26 (Tahoe)
• An Apple Thunderbolt-to-FireWire adapter

Steps

1. Download ASFW-<version>-adhoc.zip from the Releases page and unzip it.

2. Remove the quarantine flag. Gatekeeper quarantines downloaded apps:

   xattr -dr com.apple.quarantine ASFW.app

3. Disable SIP. See Apple's guide on disabling and enabling System Integrity Protection. Shut down, then boot into Recovery (hold the power button until "Loading startup options" appears → Options → open Terminal), and run:

   csrutil disable

   Reboot back into macOS. Confirm with csrutil status (should report disabled).

4. Enable system-extension developer mode. Runtime toggle, no reboot; requires SIP already off:

   systemextensionsctl developer on

5. Install the driver. Move ASFW.app to /Applications, open it, and use its Install button. Approve the extension in System Settings → General → Login Items & Extensions when prompted.

6. Verify the driver is active:

   systemextensionsctl list

   You should see net.mrmidi.ASFW.ASFWDriver marked [activated enabled].

Uninstall / revert

Remove the extension via the app, or manually (ad-hoc builds have no team ID, hence the -):

systemextensionsctl uninstall - net.mrmidi.ASFW.ASFWDriver

Then re-enable SIP from Recovery with csrutil enable.

Note

Deleting ASFW.app is not a substitute for uninstalling the extension. Uninstall first, confirm with systemextensionsctl list, and only then remove the app and re-enable SIP.

Troubleshooting

More symptoms and workarounds on Troubleshooting.

Missing entitlement com.apple.developer.system-extension.install The build was not signed with its entitlements embedded. That is a packaging bug in the release, not something to fix on your machine — please open an issue rather than changing boot-args.

The extension does not appear in systemextensionsctl list Confirm csrutil status reports disabled and that systemextensionsctl developer on was run after SIP was disabled. Both are required.

The app was not moved to /Applications Move it there and reinstall. Running it from ~/Downloads is not a supported layout.