Users updating to Big Sur against their better judgement will find themselves unable to modify system configurations after the update. Post read-only protection in Catalina, Apple has added additional write-protection to system files, that they cannot be modified.
Some additional steps now need to be followed to disable a particular system extension:
- Disable FileVault – this can take a long time particularly if the MacOS system is undergoing Kernel panic. My experience also shows that if your old Mac is being slower than usual, turning off FileVault helps tremendously with speed.
- Boot into Recovery mode (cmd + R), and run
csrutil authenticated-root disable
- A restart is required for the change to take effect. Next step is to mount a local drive and make a snapshot of system settings (to be modified and used for system); if doing this in Recovery mode, then no need for sudo
mount -uw /Volumes/Macintosh\ HD
- navigate to directory under /Volumnes/Macintosh \HD/Systems/Library/Extensions/ (note in my case, direct cd to /Systems/Library/Extensions/ shows that the directory remains read-only, so full directory is needed)
- Modify the Extension as usually do (see my previous article)
- Bless the settings by taking a snapshot (MacOS will use the snapshot as boot settings), by running:
bless –folder /Volumes/Macintosh\ HD/System/Library/CoreServices –bootefi –create-snapshot
- Reboot the system