EFI Partition – How to Change Name and Logo

bootefipartitionssd

I've installed Windows again but this time on a external SSD.
it's all working fine, but when holding the alt/option key it's giving me Macintosh HD and EFI partition.
how can I change this name "EFI Partition" and its logo?
the logo is a orange one.
and I also want it to show up in system preferences startup selector on mac OSX.
it's only showing me Macintosh HD.

Best Answer

The icon displayed in the Mac Startup Manager can be changed by putting a icon set file named .VolumeIcon.icns in the root folder of the EFI partition used by Windows. Or, you can follow the instructions at the end of this answer.

A png file can be converted to icons file by using the commands sips and iconutil. A script for doing this is given below.

#!/bin/bash
#
#
if [[ $0 != "$BASH_SOURCE" ]]; then
    bash "$BASH_SOURCE" "$@"
    return
fi

Convert() {
    local -i "n=${1%%x*}"
    [[ $1 != *@2x ]] || n="2*n"
    sips -s format png -z "$n" "$n" "$full" --out "$name.iconset/icon_$1.png"
}

Main() {
    local "full=$1"
    local "base=$(basename "$full")"
    local "name=${base%.*}"
    rm -rf "$name.iconset"
    mkdir "$name.iconset"
    Convert "16x16"
    Convert "16x16@2x"
    Convert "32x32"
    Convert "32x32@2x"
    Convert "128x128"
    Convert "128x128@2x"
    Convert "256x256"
    Convert "256x256@2x"
    Convert "512x512"
    Convert "512x512@2x"
    iconutil -c icns "$name.iconset"
    rm -r "$name.iconset"
}
set -u
Main "$@"

For example, if you were to download this Windows 10 logo png file to the same folder as the script file, then the command given below would replace the png file with a icns file. Here, the script file is named createicns and Windows10.png is the png file. The result would be the creation a Windows10.icns file, which you would rename .VolumeIcon.icns.

./createicns Windows10.png

You can also download icns files for various operating systems from this website. I converted the Windows 10 logo png file and posted here for download. The file name is Windows10.icns.

The label displayed in the Mac Startup Manager can be changed by using the bless command. Assuming diskutil list shows your external drive is disk2 and the EFI partition is first on the drive, then command below would mount this partition.

sudo diskutil mount disk2s1

Assuming the EFI volume is labeled EFI, then the command below would change the label to Windows.

bless --folder /Volumes/EFI/efi/boot --label "Windows"

This command creates the two hidden files given below.

.disk_label
.disk_label_2x

Afterwards, the command given below can unmount the EFI partition.

diskutil unmount disk2s1

The Start Disk pane in System Preferences may not shown an Windows installation on an external drive. Or, if the installation does appear, you may not be able to successfully select the installation. AFAIK there is no fix for this.

There is an alternative where rEFInd can be used to select the default operation system directly from Windows, macOS and most Linux installations. However this requires installing a GUI script in each operation system as well as installing and configuring rEFInd.

Contents of an `icns` File

The contents of a icns file can vary depending on the version of OS X or macOS you are using. The table below can be used to compare the differences between an icns file create using El Capitan (OS X 10.11.6) and one created using Catalina (MacOS 10.15.4). Both files were creating using the same script as given above. The descriptions came from Wikipedia.

 10.11   10.15   Type = Description                   
------- ------- --------------------------------------------------------------------------------------
   X             s8mk = 16x16 8-bit mask
   X             is32 = 16×16 24-bit icon
           X     ic04 = 16x16 ARGB
   X       X     ic11 = 16x16@2x "retina" icon in JPEG 2000 or PNG format
   X             l8mk = 32×32 8-bit mask
   X             il32 = 32x32 24-bit icon
           X     ic05 = 32x32 ARGB
   X       X     ic12 = 32x32@2x "retina" icon in JPEG 2000 or PNG format
   X             t8mk = 128×128 8-bit mask
   X             it32 = 128×128 24-bit icon
           X     ic07 = 128x128 icon in JPEG 2000 or PNG format
   X       X     ic13 = 128x128@2x "retina" icon in JPEG 2000 or PNG format
   X       X     ic08 = 256×256 icon in JPEG 2000 or PNG format
   X       X     ic14 = 256x256@2x "retina" icon in JPEG 2000 or PNG format
   X       X     ic09 = 512×512 icon in JPEG 2000 or PNG format
   X       X     ic10 = 1024×1024 in 10.7 (or 512x512@2x "retina" in 10.8) icon in JPEG 2000 or PNG format
   X             name = Unknown
           X     info = Info binary plist. Usage unknown

Note: The icns files produced using Catalina appeared to only work with the firmware included with newer Intel Macs. The icns files produced using El Capitan appeared to work with the firmware included with all Intel Macs. I wrote "appeared", because I could not test on all Intel Macs.

A script, that can print out the types in a icns file, can be found in the file Notes.dmg, which is part of the Mac icons project.

How to Install the icns File

Enter the command diskutil list to determine the EFI partition where the Windows 10 boot files are stored. On my Mac, I get this:

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         800.0 GB   disk0s2
   3:       Microsoft Basic Data Fish1                   98.0 GB    disk0s3
   4:       Microsoft Basic Data BOOTCAMP                91.5 GB    disk0s4
   5:       Microsoft Basic Data Fish2                   10.5 GB    disk0s5

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +800.0 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Muskie                  32.2 GB    disk1s1
   2:                APFS Volume Preboot                 107.2 MB   disk1s2
   3:                APFS Volume Recovery                1.0 GB     disk1s3
   4:                APFS Volume VM                      8.6 GB     disk1s4
   5:                APFS Volume Snapper - Data          660.0 GB   disk1s5
   6:                APFS Volume Snapper                 11.2 GB    disk1s6

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:         Microsoft Reserved                         16.8 MB    disk2s2
   3:       Microsoft Basic Data BOOTCAMP                499.9 GB   disk2s3

The only external drive is disk2. The only EFI partition on this drive is disk2s1, so this is where the Windows 10 boot files are stored. The command below will mount the volume stored in this partition.

sudo diskutil mount disk2s1

This volume appears in the Finder as EFI. If I right click on the the volume and select Get Info, the following window appears.

To install the .icns file, drag the file and drop over the icon in the upper left corner of this window, as shown below.

The result is shown below.

The .VolumeIcon.icns file normally does not appear in the Finder. To view hidden files in the Finder, the key combination ⌘+shift+. needs to be pressed. The image below shows all the files and folders in the root folder of the volume in the EFI partition.

Finally, enter the command below to unmount the EFI volume.

diskutil unmount disk2s1

References

Create a Set of Icons That Includes High-Resolution Versions
Use iconutil to Create an icns File Manually
Apple Icon Image format
SourceForge Mac icns Project

Related Solutions

EFI Partition – Fixing The Broken EFI in macOS

You can recreate the EFI System Partition (ESP) using the command-line gpt tool. It should start at sector 40, and it should be 409600 sectors (exactly 200MiB) long. The GPT entry's type should be C12A7328-F81F-11D2-BA4B-00A0C93EC93B, and if you have a hybrid MBR, the type there should be EE. The format is actually a subset of FAT, not HFS+. You can read the GPT using the command sudo gpt -r show disk0 in a Terminal window, this produces output that looks something like this:

      start       size  index  contents
          0          1         PMBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6         
         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     409640  447801712      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  448211352    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  449480888   40753831         
  490234719         32         Sec GPT table
  490234751          1         Sec GPT header

You can see the correct EFI partition at index 1. If that line doesn't match exactly, the easiest way is to delete the partition in its place and recreate it.

Make sure you know what you're doing before proceeding from here - you may lose data if you mess up.

You can't edit the partition table using gpt while partitions on the drive are mounted, so you'll need to boot from another drive (e.g. a USB stick with the OSX installer) or run the mac in target disk mode and do the partitioning from another mac. You may need to unmount any automatically mounted volumes using diskutil unmountDisk disk0 before proceeding, and in between commands.

To delete your "bad" EFI partition, run this command:

sudo gpt remove -i 1 disk0

Make sure disk0 is really the disk you want to change - the numbers can change between reboots. Also, this will only work if you already have a non-ESP partition in the place of the ESP - if not, deleting partition 1 could be disastrous! In this case, you'll need to move the indices along, as I think the ESP must have index 1. By the sound of it, this won't be necessary in your case.

Once deleted, re-add the partition with the correct layout and type:

sudo gpt add -b 40 -i 1 -s 409600 -t C12A7328-F81F-11D2-BA4B-00A0C93EC93B disk0

This should sort out the partition itself, but as you've created an HFS partition in its place, you need to fix its format as well.

The format of the EFI System Partition is documented by Apple here. As you can see, they recommend you clone an existing ESP rather than recreating the file system with newfs_msdos. If you have an external drive with a GPT partition table (OSX install stick should have it), you can clone that.

Make sure you have your disk and partition numbers the right way around or you may overwrite data:

If disk1 is your external drive, and it contains an ESP as the first partition (disk1s1) and disk0 is the drive whose ESP (disk0s1) you want to fix, run this command:

sudo dd if=/dev/disk1s1 of=/dev/disk0s1

This will copy every single block of disk1's ESP and overwrite the corresponding block in disk0's ESP with it.

Alternatively, take a gamble with newfs_msdos.

BootCamp – Resolving Mystery of ‘EFI Boot’ Partition Appearing at Startup

Your question has two parts. The first part is repeated below.

The question is, how can I make the EFI Boot disappear when I press the options key at startup?

This a duplicate of the question "Ghost partition, Windows BSOD". The rest of your question, which again is repeated below, does require further explanation.

It's not creating any problems with my Mac or Windows partitions, but I'm very curious about what it actually is, what does it have to do with my computer, and why does it decide to show up when I pressed the options key?

The "EFI Boot" appears because the Mac firmware finds the boot file BOOTx64.EFI in the folder \EFI\BOOT on the EFI partition of your internal drive. This is part of the UEFI specification. For example, if you go to the "uefi.org Specifications web page", you can download and view the "UEFI Specification Version 2.5". Sections 3.5.1.1 Removable Media Boot Behavior and 3.5.1.2 Non-removable Media Boot Behavior (on pages 88-90) describe the naming of the BOOTx64.EFI file and that it should appear in the \EFI\BOOT folder.

When holding down the Option ⌥ at startup, the Mac firmware will look for the \EFI\BOOT\BOOTx64.EFI file on each EFI partition of all drives accessible at startup. Each occurrence will generate an icon with the label "EFI Boot" on the Startup Manager menu.

When Windows installs, some of the startup files are stored in the folder \EFI\MICROSOFT. These files are also duplicated (with some renaming) in the \EFI\BOOT folder. Not all non-Apple operating systems do this when installing. For example, Ubuntu Linux does not. (Well, last time I installed in EFI mode it did not.) The Ubuntu installer does create a folder \EFI\UBUNTU with startup files (GRUB), which the Mac firmware by default ignores. To get Ubuntu to appear in the Startup Manager, you have to manually mount the EFI partition and copy the files in the \EFI\UBUNTU folder to the \EFI\BOOT folder. (Also, the copied grubx64.efi file needs to be renamed to BOOTX64.EFI.)

If you need to do this for two operating systems, then you will need a second EFI partition. This should not present a problem since an EFI partition is fairly small (<200 MB) and the limit on Macs by default is 128 partitions. However, to tell one operating system for the other, while viewing the choices presented by the Startup Manager, you may want to change the icons.

For example, I have rEFInd installed in a second 134 MB EFI partition on my iMac. (This happens to be the last of 9 partitions.) Additionally, I have Windows 10, Yosemite (on volume "Steelhead") and El Capitan (on volume "Steelhead2") installed. Below is a image of my Macs Startup Manager menu. (For a better view, click on the image or open in a new window.)

The icon can be changed by mounting the EFI partition and adding the icon file .VolumeIcon.icns to the root folder. A collection of these icons, for popular Linux and other operating systems, can be found here.