iATKOS | United Kingdom

🖥️ Situation

Mac: iMac 2017 (Intel)

Goal: Install macOS Sonoma using OpenCore Legacy Patcher (OCLP).

USB: 64 GB, successfully created with createinstallmedia → Install macOS Sonoma volume shows up and works fine.

✅ What works

I can create the Sonoma installer on the USB (disk2s2 = Install macOS Sonoma).

OCLP runs “Build and Install OpenCore” without errors.

The USB’s EFI partition mounts (disk2s1), and I can access it.

❌ The problem

The EFI partition is empty or missing the OC folder.

No BOOTx64.efi or OC/OpenCore.efi is copied.

So when I reboot and press Option (⌥), my iMac only shows the internal drives (Macintosh HD, MacSSD), never EFI Boot.

Sometimes I just get a gray screen when it tries to boot from USB.

I’ve tried creating the folder manually and renaming OpenCore.efi → BOOTx64.efi, but OCLP doesn’t seem to generate the complete EFI anywhere on my system.

🔎 What I’ve checked

diskutil list → USB detected as /dev/disk2, EFI partition = disk2s1.

Mounted EFI:

sudo diskutil mount /dev/disk2s1

ls -R /Volumes/EFI

→ only shows empty BOOT folder, no OC or other files.

Tried searching for an EFI folder OCLP might have generated in ~/Desktop, ~/Library, or /Applications/OpenCore-Patcher.app → nothing found.

❓ Question

How can I force OCLP to actually copy the full EFI folder (with OC + BOOT) to my USB’s EFI partition?

Or: is there a safe prebuilt EFI package for iMac 2017 + Sonoma that I can copy manually to the USB?