Reverting and Updating MacBook Air 2017 and iMac 2017 – Using OpenCore Legacy Patcher (OCLP) for macOS Sonoma

If you want to revert your MacBook Air 2017 back to macOS Sonoma without OCLP, and later update your iMac 2017 from Ventura to Sonoma with a fresh start on OCLP, here’s a structured approach to make this process as safe and clear as possible.

Step 1: Downgrade MacBook Air 2017 from Sequoia to Sonoma (Without OCLP)

Since your MacBook Air 2017 supports macOS Sonoma natively, you can remove OCLP and reinstall Sonoma without using legacy patches.

1. Backup Your Data:

   • Use Time Machine or another backup solution to ensure all data is saved.

2. Create a macOS Sonoma Installer USB:

   • Download macOS Sonoma from the App Store on another Mac if available.
   • Use CreateInstallMedia in Terminal to create a bootable USB:

     bash
     Copy code
     sudo /Applications/Install\ macOS\ Sonoma.app/Contents/Resources/createinstallmedia --volume /Volumes/YourUSBDrive
     

3. Erase the Drive:

   • Insert the USB installer into your MacBook Air.
   • Restart and hold Option (⌥) during boot to select the USB as the boot device.
   • Once in the macOS installer, open Disk Utility.
   • Select your main drive and choose Erase, formatting it as APFS with GUID Partition Map.

4. Reinstall macOS Sonoma:

   • Follow the on-screen instructions to install Sonoma without OCLP.
   • After installation, restore data from your backup if needed.

Step 2: Remove Legacy Patcher from MacBook Air 2017 (If Needed)

Since Sonoma is supported natively on your MacBook Air 2017, OCLP should no longer be necessary. To completely remove any residual files from OCLP:

1. Remove EFI Partition with OCLP:

   • Reboot your MacBook and hold Option (⌥) to select your boot drive.
   • If OCLP has installed a custom EFI, you may need to reset it.
   • You can remove any OCLP EFI partitions manually by remounting your EFI partition in Terminal (optional).

2. Reset NVRAM/PRAM:

   • Restart and hold Option + Command + P + R until the startup sound plays twice. This will clear any boot arguments left by OCLP.

Step 3: Update iMac 2017 from Ventura to macOS Sonoma Using OCLP

For the iMac 2017, you’ll start fresh with OCLP for macOS Sonoma.

1. Prepare macOS Sonoma Installer with OCLP:

   • Download the latest version of OCLP from GitHub.
   • Download macOS Sonoma from the App Store and create a bootable installer using CreateInstallMedia as described above.

2. Install macOS Sonoma:

   • Insert the bootable USB installer into your iMac.
   • Restart the iMac and hold Option (⌥) to boot from the USB drive.
   • Open Disk Utility to ensure your disk is in APFS format, then proceed with the macOS installation.

3. Use OpenCore Legacy Patcher:

   • After installing Sonoma, open OCLP on your iMac.
   • Apply Post-Install Patches to ensure all drivers and components function correctly with Sonoma.

Notes and Best Practices

• Troubleshooting: If you encounter issues, you can use the OCLP community forums or GitHub issues page, especially if patches don’t apply correctly or hardware isn’t functioning as expected.
• Stability: Sonoma is still being tested on older hardware, so minor bugs may occur. Keep OCLP updated to take advantage of new fixes.
• Backups: Always keep backups before making significant OS changes, especially when using OCLP.

By following these steps, you should have your MacBook Air 2017 running a clean, unpatched version of macOS Sonoma and your iMac 2017 upgraded to Sonoma with OCLP. Let me know if you have specific questions or encounter issues along the way!