Troubleshooting macOS Installation Issues: EFI Partition Confusion at 29 Minutes

Guide: Resolving the 29-Minute Restart Issue During macOS Installation

If your 100% configured EFI partition works fine once copied to the system drive but causes a reboot at the 29-minute mark during installation, it's likely due to a configuration issue in your initial EFI setup. There are a few common causes for this problem, and we’ll walk through them with step-by-step solutions.

Potential Causes for the 29-Minute Restart Issue

1. Incompatible or Incorrect Kexts:

   • During the installation phase, macOS relies on a minimal set of drivers (kexts) to get the system running. Once installed, more kexts can be loaded, allowing the system to boot. A fully configured EFI might include drivers that are incompatible or too aggressive for the installation phase, especially with certain hardware.

2. Boot Arguments and Kernel Panic:

   • Specific boot arguments in your config.plist might cause kernel panics during the installation phase but work after the system is installed. For example, certain graphics, CPU, or ACPI fixes might only be necessary after the installation has been completed and the system is booting for the first time.

3. Missing or Overcomplicated Configuration:

   • Sometimes a perfectly configured EFI might not be ideal during the initial installation, as the installer expects a simpler environment to boot the system without complex fixes or changes. If there are too many advanced settings in the config.plist, this could interfere with the installation process, leading to restarts.

4. File System or APFS Issues:

   • If you're using an unsupported file system or the APFS container isn’t set up correctly, macOS may fail during installation or restart unexpectedly.

Step-by-Step Troubleshooting and Fixes

Step 1: Revert to Minimal EFI During Installation

1. Create a Minimal EFI Partition:

   • Remove unnecessary kexts and settings from your config.plist. Ensure only the basic kexts (like Lilu.kext, WhateverGreen.kext, and VirtualSMC.kext) are present, along with essential boot arguments (-v, dart=0, npci=0x3000).
   • Use a minimal config.plist for the installation phase, avoiding complex configurations.

2. Boot with Minimal EFI:

   • Boot into OpenCore (or Clover) with this minimal EFI partition and try installing macOS again.
   • If this works, you can proceed to the next step.

Step 2: Identify the Cause of Restart at 29 Minutes

1. Check Verbose Output:

   • Boot into verbose mode (-v boot argument) to check the system log and look for errors or kernel panics at the point where it restarts. This can provide insight into what is failing during the installation.

2. Remove Over-Advanced Fixes:

   • After installation, once macOS is installed but not bootable, check the config.plist for over-advanced fixes that may not be necessary during installation (e.g., some ACPI patches, specific IGPU fixes, or specific framebuffer settings).
   • Remove any settings that could be too complex for the installation phase and leave only the essential configurations.

Step 3: Revert and Reconfigure EFI Post-Installation

1. Install macOS Using Minimal EFI:

   • After installation completes (or after the system restarts), go back into the System EFI Partition.
   • Copy your fully configured 100% EFI folder into the System EFI partition from your USB.

2. Post-Installation Configuration:

   • Once macOS successfully boots, you can now test the more advanced fixes, kexts, and configurations. This ensures that the 100% EFI works once the installation phase is complete.

3. Check for Updates and Kernel Panic Logs:

   • If macOS still doesn’t boot after switching back to your complete EFI, check the system logs for any kernel panics or errors. These logs will help pinpoint if there’s an issue with a specific driver or configuration.

Example of Minimal EFI Configuration for Installation

Here’s an example of a minimal config.plist to use during the installation:

xml
Copy code
<key>PlatformInfo</key>
<dict>
    <key>Generic</key>
    <dict>
        <key>SystemProductName</key>
        <string>iMac20,1</string> <!-- Example SMBIOS -->
        <key>SystemSerialNumber</key>
        <string>XXXXXXXXXXXXX</string>
        <key>MLB</key>
        <string>XXXXXXXXXXXXX</string>
    </dict>
</dict>

<key>boot-args</key>
<string>-v dart=0 npci=0x3000</string> <!-- Simple boot args -->

In this example, we’ve left out advanced fixes and additional kexts. After macOS is installed and booting properly, you can add your additional fixes back into the EFI.

Conclusion

If your fully configured EFI works after installation but fails during the process, it is likely caused by one or more of the following:

• Incompatible or unnecessary kexts during installation.
• Overly complex boot arguments or configurations that are not required for the initial installation phase.
• APFS or file system issues during installation.

By simplifying the EFI during the installation process and applying more advanced settings post-install, you should be able to resolve the 29-minute restart issue and ensure a smooth installation and boot process.