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Make the USB stick

The stick needs two things: the EFI folder you just built, and macOS itself. There are two ways to get the second, and they lead to different sticks.

Where macOS comes from What it costs
Recovery The program downloads it About 700 MB. Boots, connects, and downloads the rest of macOS on the machine being converted. Needs a network card macOS already drives. Any 2 GB stick.
A ready image You download it from this site 12 GB or so of .raw, written with balenaEtcher. Installs with no network at all. 16 GB stick or larger.

Recovery is the shorter road and the one the program can do end to end. An image is the answer when the machine has no network macOS can use during the install, or when the connection is too slow to trust.

With recovery - the program does all of it

  1. Open the Recovery pane, pick the macOS you want, and press download.

    The top row asks for whatever Apple is serving today; the rows under it are named releases. It saves BaseSystem.dmg and BaseSystem.chunklist into a com.apple.recovery.boot folder.

  2. Open the USB stick pane. It lists the removable disks it can see and says, for each, whether it is ready as it stands - FAT32 under GPT with room

  3. or has to be erased first. If it has to be, press format and type the disk's name when it asks.

  4. Press copy. It puts both folders at the root of the stick, side by side:

/Volumes/USB/
├── EFI/                       the folder the builder wrote
└── com.apple.recovery.boot/   BaseSystem.dmg + BaseSystem.chunklist

That is the whole stick. Nothing goes inside EFI that was not already there, and the recovery folder is not inside it either - OpenCore looks for that name beside itself.

Boot from the USB and the OpenCore picker lists macOS Base System. Pick it, and the installer downloads the rest of macOS itself.

The download happens on the machine being converted

Not on the one that made the stick. That machine needs Ethernet, or a Wi-Fi card macOS already drives, while it installs.

The Recovery pane now says which of these you are, before you download anything, reading it off the hardware report:

What it says What it means
This machine can download during the install Wi-Fi has a macOS driver. Nothing else to do.
Use an Ethernet cable for the install Your Wi-Fi has no macOS driver, but your Ethernet does. Recovery works — plug a cable in before you start. This is the common case on laptops with Realtek Wi-Fi.
Recovery cannot finish on this machine Neither card is driven. Use a whole image instead, or fit a supported card.
Not known for this machine No report to read. It will not guess.

With an image

  1. Take a .raw from macOS images and extract it from the zip.

  2. Download balenaEtcher. Click Flash from file and choose the .raw, click Select target and choose the USB drive, then Flash!

    Flashing the image with balenaEtcher

  3. When it finishes, unplug the stick and plug it back in. An EFI partition appears in My Computer.

  4. Copy your EFI folder into that partition, replacing what is there. The USB stick pane will do it if the partition shows up in its list; otherwise drag it across yourself.

Now you can boot from USB.

Before you sign in to anything Apple

Each config.plist ships with a serial number, MLB and UUID of its own, but everyone who downloads the same file shares them, and ROM is a placeholder (11:22:33:44:55:66) because it has to be your own machine's MAC address.

Generate your own with the Post installation steps before signing in to iCloud, iMessage or FaceTime.

Adjust BIOS settings :material-arrow-right: