No luck getting the old Sample USB Audio config to work under 12.4
Steps:
- Looked up my Realtek USB device vendor and product IDs in ioreg and coverted from hex to decimal
— cross-checked the ids provided in another user's Sample with a linux USB vendor database to be sure I'm getting the codes right.
- Edited the Sample.kext/Contents/Info.plist to add IDs and rename config
— cross checked various top level boilerplate config keys with a more modern kext and updated
- Placed Sample.kext in /Library/Extensions (Since SSV hardening, /S/L/E is off limits)
- chown -R root:wheel /L/E/Sample.kext & touch /L/E
- Disabled SIP in OC and verified SIP status
The config change doesn't take.
It's not clear to me if kmutil (kext manager command) should show "loaded" status for codeless kexts, but the kext is not reported as loaded. If I load it by hand, the command runs quietly.
I played around with locally signing the kext and System Report > Extensions reports different signing status...
Overall: FAIL
Maybe the way of massaging USB audio devices is just out of date.
This old Apple document has additional description of USB audio, but its developer links have rotted.
TN2274: details Apple's support for USB audio to help developers design class compliant devices that work seamlessly with the Mac.
developer.apple.com
Next step, look more carefully at Xcode support for Audio Plugins.
