EFI Boot Partition Appearing in Startup Manager

If you’re encountering the specific issue where the EFI boot partition appears in the Startup Manager while dual-booting Windows and macOS on a MacBook, it’s likely due to both operating systems having their own EFI partitions.

This is not necessarily an error; it’s a normal behavior when dual-booting on Mac hardware. The Startup Manager shows all available boot options, which may include multiple EFI partitions corresponding to each operating system. But first a short note on EFI Boot.

What is EFI Boot on macOS?

EFI (Extensible Firmware Interface) is a modern replacement for the older BIOS (Basic Input/Output System) firmware used in most computers. It is a firmware interface that provides a standardized way for the operating system to interact with the hardware.

It uses an EFI System Partition (ESP) on the storage device, containing boot loader programs. These loaders start the OS. UEFI (Unified Extensible Firmware Interface) is the standard that governs this process. It’s an improvement over the older BIOS system.

The EFI boot process involves the following key components:

1. EFI Firmware

This is the firmware program that is stored in a memory chip on the computer’s motherboard. It initializes the hardware components during startup and hands control over to the operating system.

2. EFI System Partition (ESP)

This is a special partition on a storage device (usually the system drive) that contains bootloader programs and other essential files necessary for booting the operating system. The ESP is formatted with the FAT32 file system, making it readable by both EFI firmware and the operating system.

3. Boot Loader

The boot loader is a small program stored in the EFI system partition. It is responsible for loading and starting the operating system. Different operating systems (like Windows, macOS, and Linux) have their own bootloaders.

4. Boot Manager

The EFI firmware contains a built-in boot manager, which is responsible for presenting a menu of available boot options to the user during startup. This menu allows the user to select which operating system to boot into.

5. UEFI

UEFI (Unified Extensible Firmware Interface) is a standard specification that defines the software interface between the operating system and the firmware. It provides enhanced features compared to traditional BIOS, including support for larger storage devices and improved security.

6. GPT

GUID Partition Table (GPT) is a partitioning scheme for modern storage devices. It is part of the UEFI standard and allows for more partitions and larger partition sizes compared to the older MBR (Master Boot Record) scheme.

Overall, the EFI boot process provides a more flexible and capable system for booting operating systems compared to the older BIOS system. It has become the standard on most modern computers, particularly those released after the mid-2000s.

How To Fix EFI Boot Partition Appearing in Startup Manager?

Okey now that we understand what is EFI Boot. Now we are going to fix the EFI Boot appearing in Startup Manager. To fix the issue of the EFI Boot Partition appearing in the Startup Manager, follow these steps:

Method 1: Check Boot Options

Restart your Mac or MacBook and hold the Option to access the Startup Manager.

From there, select the desired operating system from the available boot options.

Method 2: Set Default Boot Option

Setting the default boot option ensures your preferred operating system starts automatically if no choice is made during startup.

In macOS, go to System Preferences > Startup Disk. Here, you can select the preferred operating system. This will become the default choice at startup.

In Windows, use the Boot Camp Control Panel to set the default. This prioritizes one OS over the other, resolving issues with multiple EFI partitions. This preference remains until manually changed, streamlining the boot process.

Method 3: Reorder Boot Entries

By changing the order of boot entries, you can fix the EFI Boot appearing in Startup Manager. In the Startup Manager, use the arrow keys to move up or down through the list of boot options. This can help you set the default boot option.

Method 4: Remove Unnecessary Boot Entries

Removing unnecessary boot entries involves cleaning up the list of available boot options in the EFI firmware. This can help prevent confusion and streamline the startup process.

However, it’s important to proceed with caution, as deleting the wrong entry can potentially render your system unbootable. Here’s a detailed explanation of how to perform this task:

NOTE: It’s important to exercise caution while performing this operation. Deleting the wrong entry can potentially lead to boot problems. If you’re uncertain about a specific entry, it’s best to seek other methods. Additionally, always back up important data before making any significant changes to your system configuration.

• Restart your computer and access the EFI shell. The method for doing this can vary depending on your system, but it typically involves pressing a specific key (like F2, F12, DEL, or ESC) during startup to enter the UEFI/BIOS settings.
• Once in the EFI shell, use the command “bcfg boot dump” (which can vary by system) to list the available boot entries.
• Examine the list of boot entries to identify which ones are unnecessary or duplicates. Pay close attention to the labels or descriptions to differentiate between them.
• Use the command to delete a specific boot entry. The command might look something like “bcfg boot rm <bootnum>”, where “<bootnum>” is the number associated with the entry you want to remove.
• Confirm the deletion when prompted. Be absolutely sure that you’re deleting the correct entry.

After removing the unnecessary entries, exit the EFI shell and restart your computer.

Method 5: Check Disk Utility (macOS)

Checking Disk Utility in macOS involves using a built-in tool to inspect the disk partitions, including the EFI system partition. This can help identify and correct any issues related to multiple EFI partitions. Here’s a step-by-step guide:

NOTE: This method helps ensure that there are no unnecessary or conflicting EFI partitions on your system. However, exercise caution and be absolutely certain before making any changes, as modifying partitions can potentially lead to data loss or system instability.

• Open Disk Utility in macOS. You can search for it in Spotlight or find it in the Utilities folder within Applications.
• Select the disk that contains the macOS installation (usually labeled something like “Macintosh HD”).
• View partition information and inspect the partition layout to see if there are multiple EFI partitions listed. They will be labeled as “EFI” and may have different sizes.
• Identify which one corresponds to each operating system.
• Select the EFI partition and click the Verify Disk button. Disk Utility will check for any errors or inconsistencies on the partition.
• If Disk Utility finds any issues, click Repair Disk to attempt to fix them.

After the repair process is complete, close Disk Utility and restart.

Method 6: Reinstall the Boot Loader

If you’ve recently installed or reinstalled an operating system, it’s possible that the bootloader was installed in the wrong location. You may need to reinstall the bootloader to the correct EFI partition.

Boot from Installation Media (Insert the installation USB/DVD).

Access Recovery/Repair Mode by holding Command+R while the system reboots.

Follow the on-screen prompts and choose Reinstall macOS.

     bootrec /fixmbr

     bootrec /fixboot

     bootrec /rebuildbcd

After completion, remove the media and restart.

Method 8: Check Boot Order in UEFI/BIOS

Checking the boot order in the UEFI/BIOS settings ensures that the correct drive or partition is set as the primary boot device. This helps prevent the EFI Boot Partition from appearing in the Startup Manager. Here’s how to do it:

• Restart and access the UEFI/BIOS settings. This is usually done by pressing a specific key (like F2, F12, DEL, or ESC) during startup.
• Now look for a section related to boot. This might be labeled as Boot, Boot Options, Boot Order, or something similar.
• Here you will see a list of available boot devices. Use the provided instructions (usually indicated at the bottom of the screen) to change the boot order.
• Use the appropriate keys to move the desired boot device to the top of the list. This ensures that the system will attempt to boot from that device first.
• Save and Exit.
• Let your computer restart normally.

After the restart, access the Startup Manager and verify if the list of boot options is now correct.

By setting the correct boot order, you ensure that the UEFI firmware attempts to boot from the correct drive or partition, reducing the likelihood of the EFI Boot Partition appearing in the Startup Manager.

In conclusion, encountering the EFI Boot Partition in the Startup Manager, especially when dual-booting macOS and Windows on a Mac, can be resolved through various methods. From checking boot options to reordering entries, and even delving into the UEFI/BIOS settings, these steps offer effective solutions. Remember to proceed with caution, especially when dealing with system configurations.