OC4VM - recoveryOS Image Maker

Introduction

This is a utility to download the recovery image, recoveryOS, for macOS from Apple's servers and create a bootable virtual disk file that can be used to start an Internet installation of macOS.

Pre-requisites

Python 3

The tool is written in Python 3 and so Python must be installed on the host computer. Python 3.10 was used for the development of the tool, so 3.10 or a later version should be installed.

• Linux - Use your distro package manager
• macOS - brew install python3
• Windows - Recommended way is to install Python 3.10+ from the Microsoft App Store, or use Chocolatey or Scoop.

qemu-img

You will need to have qemu-img utility, from QEMU, on the path.

• Linux - These can be installed from Linux repos, for example Debian based distros

  sudo apt install -y qemu-utils

• macOS - use brew package manager to install on macOS

  brew install qemu

• Windows - use Chocolatey or Scoop to install on Windows

  choco/scoop install qemu

Instructions

1. Unzip the archive maintaining the folder structure
2. Open a console/shell in the folder with the tool
3. Run the tool: python3 recovery-vmdk.py
4. The menu will be displayed and just select the macOS version you want using the number on the menu.

OC4VM recoveryOS Image Maker
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(c) David Parsons 2022-24

Create a recoveryOS virtual image
1. Catalina
2. Big Sur
3. Monterey
4. Ventura
5. Sonoma

After downloading the DMG fie you are then prompted to select the virtual formats you want created from the base image.

Convert the recoveryOS virtual image
1. VMware VMDK
2. QEMU QCOW2
3. Micorsoft VHDX
4. Raw image
5. All
0. Exit

The tool will download the BaseSystem.dmg for the macOS version you selected and convert it to a virtual disk format.

After the tool has finished there will be 3 or more files present in the folder. For example if downloading Sonoma and selecting all virtual disk formats there will be:

• sonoma.dmg
• sonoma.chunklist
• sonoma.vmdk
• sonoma.qcow2
• sonoma.vhdx
• sonoma.raw

The .dmg and .chunklist files are the original files downloaded from Apple and can be removed if not needed.

Occasionally you may get this error:

ERROR: "HTTP Error 403: " when connecting to http://osrecovery.apple.com/InstallationPayload/RecoveryImage

Just re-run the command and it should work.

Acknowledgements

This tool wraps several other great open source software. Thanks to the authors of those tools.

• macrecovery.py - https://github.com/acidanthera/OpenCorePkg
• qemu - https://www.qemu.org
• qemu-img for Windows - https://cloudbase.it/qemu-img-windows