On an Intel-based Mac that previously used macOS Sierra 10.12.4 or later, you can use Shift-Option-Command-R at startup to install the macOS that came with your Mac, or the closest version still available.
- Supported version: 0.6.5
While you don't need a fresh install of macOS to use OpenCore, some users prefer having a fresh slate with their boot manager upgrades.
- Mac OS High Sierra 10.13 ISO or DMG. Download only the stub installer means web installer is the main reason that only users may be downloading from the app store. The stub installer is mainly little in size. After running the stub installer, the real operating system will begin being introduced.
- Chrome OS is made for Chromebooks that are designed to be lightweight and simple. Google does all of the updates. It’s one of the simplest operating systems you can get. Chromium OS is an unofficial open-source version of Chrome OS, and it can work with all devices including Mac, Linux, and Windows.
- If you happen to have access to a Mac that's running an older version of macOS, log into the Mac App Store with your password and download the Mojave installer on that Mac. Alternatively ask a.
- The installer will be called 'Install macOS High Sierra' or something similar and will have an image of a ridge of mountains on it. As long as the installer is present in the Applications folder, you can proceed.
To start we'll want to grab ourselves a copy of macOS. You can skip this and head to formatting the USB if you're just making a bootable OpenCore stick and not an installer. For everyone else, you can either download macOS from the App Store or with Munki's script.
# Downloading macOS: Modern OS
- This method allows you to download macOS 10.13 and newer, for 10.12 and older see Downloading macOS: Legacy OS
From a macOS machine that meets the requirements of the OS version you want to install, go directly to the App Store and download the desired OS release and continue to Setting up the installer.
For machines that need a specific OS release or can't download from the App Store, you can use the Munki's InstallInstallMacOS utility.
In order to run it, just copy and paste the below command in a terminal window:
As you can see, we get a nice list of macOS installers. If you need a particular versions of macOS, you can select it by typing the number next to it. For this example we'll choose 10:
- macOS 11, Big Sur Note: As this OS is quite new, there's still some issues with certain systems to resolve. For more information, see here: OpenCore and macOS 11: Big Sur
- For first time users, we recommend macOS 10.15, Catalina
- Nvidia GPU Note: Reminder to verify whether your hardware support newer OSes, see Hardware Limitations
This is going to take a while as we're downloading the entire 8GB+ macOS installer, so it's highly recommended to read the rest of the guide while you wait.
Once finished, you'll find in your ~/macOS-Installer/
folder a DMG containing the macOS Installer, called Install_macOS_11.1-20C69.dmg
for example. Mount it and you'll find the installer application.
- Note: We recommend to move the Install macOS.app into the
/Applications
folder, as we'll be executing commands from there. - Note 2: Running Cmd+Shift+G in Finder will allow you to easily jump to
~/macOS-installer
From here, jump to Setting up the installer to finish your work.
# Downloading macOS: Legacy OS
- This method allows you to download much older versions of OS X, currently supporting all Intel versions of OS X(10.4 to current)
# Legacy macOS: Offline method
This method allows us to download full installers from Apple, however is limited to 10.10, Yosemite, so older OSes will need to be grabbed via the 'Online Method' mentioned below.
To start, go to the following link:
Download your desired version and a .pkg file should be provided.
Depending on what OS you're on, you can run this script and head to Setting up the installer however if you receive this error:
This means we'll need to manually extract the installer.
# Extracting the Installer
To start, grab the InstallMacOSX/InstallOS.dmg and mount it:
Next, let's open up terminal window and make a folder on our desktop to break things. Run one at a time:
Now we get to the fun part, extracting the installer(Note this may take a few minutes):
- For El Capitan(10.11) and older:
- For Sierra(10.12):
Next, run the following(one at a time):
- Yosemite:
- El Capitan:
- Sierra:
Once this is done, you can head to Setting up the installer!
# Legacy macOS: Online method
This method allows us to download legacy versions of macOS including 10.7 to current, however these are only recovery installers so require an internet connection inside the installer itself
To start, you'll want to use macrecovery.py instead. This tool is actually already bundled in OpenCorePkg:
Instructions for running are quite simple, choose from one of the below commands depending on which OS you want to download:
From here, run one of those commands in terminal and once finished you'll get an output similar to this:
Once this is done, format your USB as FAT32 with GUID Partition Scheme:
And finally, create folder on the root of this drive called com.apple.recovery.boot
and place the newly downloaded BaseSystem/RecoveryImage files in:
From here, you can skip to Setting up OpenCore's EFI environment
# Legacy macOS: Disk Images
This method instead relies on hosted images either from Apple or Acidanthera, and restoring onto your drive.
# Acidanthera Images
The below installers were pulled from genuine Mac restore disks with their SMBIOS lock removed, contents of OS X itself have not been modified in any way.
# Apple Images
Note that these images require you to have an Apple Developer account to access.
# Restoring the drive
Now comes the fun part, you'll first want to open the dmg you just downloaded and have it mounted. Now open Disk Utility and format your drive as macOS Extended(HFS+) with a GUID partition map:
Next we have 2 options to follow:
- ASR Restore(Apple Software Restore)
- Terminal based, works with SIP enabled
- Disk Utility Restore
- May require SIP disabled in newer OSes
# ASR
Here you'll simply want to open terminal and run the following:
- Note: This may not align with your setup, please change accordingly:
- Change
/Volumes/Mac OS X Install DVD
to what your mounted Disk Image is called - Change
/Volumes/MyVolume
to what your USB is called
- Change
This will take some time but once you're finished, you can skip to Setting up OpenCore's EFI environment
# Disk Utility
Due to some pesky issues with Disk Utility, many restores can fail if SIP is enabled. If you have issues we recommend either using the ASR Method or disable SIP.
Download The Macos Installer (pkg) Hack From The Macrumors Forum
To start, open Disk Utility and you should see both your USB drive and the Disk Image in the sidebar. From here, select restore
This will take some time but once you're finished, you can skip to Setting up OpenCore's EFI environment
If you get an error such as this one during restore:
This likely means SIP needs to be disabled, however we recommend using ASR Method instead.
# Setting up the installer
Now we'll be formatting the USB to prep for both the macOS installer and OpenCore. We'll want to use macOS Extended (HFS+) with a GUID partition map. This will create two partitions: the main MyVolume
and a second called EFI
which is used as a boot partition where your firmware will check for boot files.
- Note: By default, Disk Utility only shows partitions – press Cmd/Win+2 to show all devices (alternatively you can press the View button)
- Note 2: Users following 'Legacy macOS: Online method' section can skip to Setting up OpenCore's EFI environment
Next run the createinstallmedia
command provided by Apple(opens new window). Note that the command is made for USB's formatted with the name MyVolume
:
This will take some time so you may want to grab a coffee or continue reading the guide (to be fair you really shouldn't be following this guide step by step without reading the whole thing first).
You can also replace the createinstallmedia
path with that of where your installer's located (same idea with the drive name).
Pulled from Apple's own site: How to create a bootable installer for macOS(opens new window)
# Legacy Setup
For systems not supporting UEFI boot, see below:
To start, you need the following:
- BootInstall_IA32.tool or BootInstall_X64.tool
- This can be found in OpenCorePkg under
/Utilties/LegacyBoot/
- This can be found in OpenCorePkg under
- Install USB(Created above)
Within your OpenCore build folder, navigate to Utilities/LegacyBoot
. Here you'll find a file called BootInstall_ARCH.tool
. What this does is install DuetPkg to your desired drive.
Now run this tool in terminal with sudo(This tool will likely fail otherwise):
This will give you a list of available disks, choose yours and you will be prompted to write a new MBR. Choose yes[y]
and you'll be finished.
This will provide you with an EFI partition with either a bootia32 or bootx64 file
# Setting up OpenCore's EFI environment
Setting up OpenCore's EFI environment is simple – all you need to do is mount our EFI system partition. This is automatically made when we format with GUID but is unmounted by default, this is where our friend MountEFI(opens new window) comes in:
You'll notice that once we open the EFI partition, it's empty. This is where the fun begins.
# Now with all of this done, head to Setting up the EFI to finish up your work
Attempting to download macOS Catalina from the Mac App Store you may find that a small version of the “Install macOS Catalina.app” file downloads to the “Applications” folder, rather than the complete 8.1 GB installer file.
The tiny (just tens of megabytes) incomplete installer requires an internet connection during usage to download the rest of the Catalina update files. Additionally, it does not allow to create a macOS Catalina USB installer drive for use on multiple computers.
In this tutorial, I’ll show you how to download the complete “Install macOS Catalina.app” file from Apple server using the “macOS Catalina Patcher” app instead of via the Mac App Store.
A similar mini-installer issue occurred previously with some users getting a tiny incomplete macOS High Sierra installer and macOS Mojave installer too and I covered a similar workaround here and here to download the complete installer file from Apple server.
About the app
In this workaround, we’re going to use the macOS Catalina Patcher app from the dosdude1.com. This app is intended for those with unsupported Macs and Hackintosh users, but any Mac user can use the app to be able to download the complete macOS Catalina installer file from Apple server. For our purposes in this particular walkthrough, we will use the app only to download the complete installer file.
Note! This method relies on a third party app from an unverified third party source. If you are not comfortable with using unvetted and unverified software, do not follow this process.
Let’s begin
Downloading the complete “Install macOS Catalina.app” file from Apple server using the “macOS Catalina Patcher” app is a really easy process. Now, step by step guide.
Go to the official website of the “macOS Catalina Patcher” app here and download the app.
The download link is labeled as “Download Latest Version” on that page.
Launch the “macOS Catalina Patcher” app.
Note! By default, macOS preventing apps from unidentified developers or sources from being launched. So you most likely will get an alert message that says: “macOS Catalina Patcher.app can’t be opened because it is from an unidentified developer”. To allow just one specific app to run do the following:
- Hold down the
Control
key and click the app icon. From the contextual menu chooseOpen
. - A popup will appear asking you to confirm this action. Click the
Open
button.
Click the “Continue” button, and then select “Download a Copy”.
Confirm that you want to download the “Install macOS Catalina.app” app to start the download to your hard drive.
Close the “macOS Catalina Patcher” app when the download is complete and locate the “Install macOS Catalina.app” file you downloaded.
Note! The download will be completed when you are prompted to choose an installation method. See the screenshot below.
Conclusion
That’s it, you’re done. Now you have the complete “Install macOS Catalina.app” file downloaded. So simple isn’t it?
How Do I Download The Mac Os Installer
You can confirm that you have the complete “Install macOS Catalina.app” file by getting info on the file. For this simply select the file and click the Spacebar
key (or right-click on the file and choose “Get Info”). The complete installer should be around 8.1 GB rather than the tiny (just tens of megabytes) incomplete installer that requires additional downloads.
Note! Remember, the “Install macOS Catalina.app” file deletes itself automatically after macOS Catalina has successfully installed. Therefore, you may want to make a backup by having previously copied it to external storage.
Let me know in the comments section if you know another way to download the complete “Install macOS Catalina.app” file rather than the tiny incomplete installer.
Mac Os X Installer
I hope this article has helped you learn how to downloaded the complete “Install macOS Catalina.app” file from Apple server. If this article has helped you then please leave a comment
Mac Os Iso
Thanks for reading!
Arthur is a designer and full stack software engineer. He is the founder of Space X-Chimp and the blog My Cyber Universe. His personal website can be found at arthurgareginyan.com.