I've had a Macbook Pro for a year or so now and have experimented with quite a few Linux distributions which have added and changed things in the EFI Boot Order. I am looking to clean things up. The tool efibootmgr for Linux does let me make changes and cleanup as necessary. However will resetting NVRAM reset the EFI Boot Order for me?

Just tried to install Windows on an external SSD, but mistakenly deleted partitions on a Mac SSD from the Windows installer. I had 2 partitions: - Macintosh HD (APFS) - MacData (ExFat, ~108 GB) So I deleted system partitions (EFI, Recovery, ...) and Macintosh HD, but MacData is not touched. Just booted to recovery mode with internet connection. Disk Utility shows only MacData partition. Is there any way to recover these partitions from the Mac Recovery mode terminal? Here is the result of gpt -r show disk0: ![Photo of Terminal output of the command 'gpt -r show disk0' ][1]

If I want to install another OS (say, a Linux-based one) on old hardware, with a 64-bit CPU, that originally came with macOS, I need to know what word size the EFI is, in order to know whether to add a BOOTIA32.efi to the installation media, if it doesn't support mixed-mode booting. The reason that that is a concern is that some old macOS-default hardware includes a 32-bit EFI despite a 64-bit CPU. Usually, I would ascertain this information by contacting Apple, or acquiring a specification sheet, but ["Apple does not maintain specifications for old hardware"](https://discussions.apple.com/thread/250022836?answerId=250022836021&sortBy=rank#250022836021:~:text=Since%20that%20is%20an%20obsolete%20product%20Apple%20no%20longer%20maintains%20a%20spec%20sheet%20for%20it.%20According%20to%20another%20specs%20source%20the%202007%20MacBooks%20have%20a%2064%2Dbit%20architecture.) , I have on good authority. Worse yet, such hardware doesn't include an EFI shell by default (and I don't know how to ascertain this from startup.nsh anyway). Consequently, I need to acquire this information from the preinstalled OS. In a Linux installation, cat /sys/firmware/efi/fw_platform_size provides this information, returning "32" for a 32-bit EFI, and "64" for a 64-bit EFI. Does XNU expose an equivalent?

I can't figure out how to **rename boot entries** on a MacBook Air 2012, i.e. those that appear when holding alt during boot. The problem was initially that my EFI Ubuntu installation could only be booted with the boot entry called "EFI Boot", which wasn't very descriptive, but I could live with it. The current problem is that since I installed OpenCore (a third party boot loader that enables Big Sur on this Macbook model) it *replaced* the Ubuntu boot entry with its own entry, which uses the same name ("EFI Boot"). I'm assuming this replacement happened because of the name collision (?). As I see it, the first step of the solution would then be to **change the name of the current "EFI Boot" entry** (that starts OpenCore) so that when I try to recreate the Ubuntu boot entry later the OpenCore entry won't get overwritten. I can't figure out how to do this. --- #### What I've tried I've tried customizing a suggestion from Apple Community that advised how to do it for an Ubuntu .efi (after mounting the ESP): sudo bless --folder /Volumes/EFI/EFI --file /Volumes/EFI/EFI/OC/OpenCore.efi --label "OpenCore" --shortform --verbose The above command succeeded (in Big Sur), but had no discernible effect on the boot menu upon reboot. --- #### Related I have also read several suggestions that I'm struggling to make sense/use of: 1. One answer only pertains to macOS (Monterey) , and explains that its boot.efi resides on an APFS volume. To me it appears that — on my machine — there's a boot.efi on my ESP (FAT32) in /System/Library/CoreServices, so I don't think I can make use of that even if my goal were to rename an entry for macOS (which it isn't). 2. Another answer suggests that you'd just have to rename the volume an OS resides on, but I'm not trying to rename a boot entry corresponding to an OS on a particular volume. Even if I were, the answer implies mounting (?) a Linux filesystem as a volume in macOS, which isn't something that's readily available. 3. The third answer says that .VolumeIcons.icns should be on a Mac OS Extended formatted volume, and the name of such a volume will appear in the boot menu. I have no such volumes — only FAT32 (ESP), APFS (Mojave, Big Sur), NTFS (Windows 10) and EXT4 (Ubuntu). I have a .VolumeIcon.icns on the ESP though. But I still can't make sense of it since the question asks about renaming a boot entry for Windows, which I doubt is installed on Mac OS Extended. Even if it were, the entry I want to rename doesn't have its own volume to the best of my knowledge.

When booting opensuse via rEFInd, the kernel options are wrong (the root device name is incorrect). Where do the kernel arguments that rEFInd is using come from, and how do I modify them? The line I'm looking for is of the form ro root=/dev/disk/by-id/ata-APPLE_SSD_SM768E_S119NYAC612 initrd=boot\initrd-3.7.xxx-default The root argument should be ata-APPLE_SSD_SM768E_S119NYAC612130-part7 as that is where the SUSE root partition is. If I edit the boot options from the rEFInd menu (higlight the SUSE entry, hit F2, hit F2 again on the default entry) and modify the options to include the 130-part7 suffix, everything works fine. If not, Linux asks me: > Could not find /dev/disk/by-id/ata-APPLE_SSD_SM768E_S119NYAC612. > Want me to fall back to > /dev/disk/by-id/ata-APPLE_SSD_SM768E_S119NYAC612130-part7? (Y/n) I'd happily hit "Y" here and move on but, unfortunately, the keyboard doesn't work at this stage in the boot process. If I attach a USB keyboard, it works, but I really don't want to carry one around with me. (Perhaps there is a market for a one-key USB keyboard that can be programmed for these things. Dear God...) So, I am left changing the options via the rEFInd menu every time I boot Linux. I'd thought about adding a symlink directing ...612 to ...612130-part7, but the links in /dev/disk/by-id/ are stored in tempfs (ie, not persistent). Also, that is a crappy solution. Help?!

Let me tell you the story to understand the problem. I installed Ubuntu 20.04 on my mac as the second OS. Later I decided to delete it, and being not good in all this stuff, I decided to just remove the 30gb partition I gave for Ubuntu. However, EFI partition was left. I downloaded Paragon and erased this EFI. But it is not merged still with my Macintosh HD. I tried to format it as HFS+ and then tried to make it APFS but my system felt and I had to install macOS again. Disk Utility says that there is a trouble and to repair it, I need to go to recovery mode. But when I go to RM, it says the same thing - even though I turned off filevault as some sources say. So my question is how to merge it (include literally the 314.57 Mb partition) with my hard disk (APFS-container)?

I have an old MacBook Air 2015. I recently installed Linux Ubuntu 2024 on it on a new ext4 partition. I can dual boot between macOS 12 and Ubuntu whenever I want by holding option key on startup. Since all my family uses this Mac I want the boot priority to stay on macOS, so my family doesn't have to deal with dual booting options at startup. I know I can set startup disk in macOS system preferences and I also use efibootmgr -o xxxx,yyyy on Linux to change this boot order, but the problem is any time I switch from macOS to Ubuntu from the startup disk chooser (by holding option key on startup), the boot order is set back to Ubutnu partition, so I have to change this order again after I finish my work. Is there any way to change this behavior so that boot priority is always macOS no matter what the last used OS is?

I'm looking at the /EFI partition, and it has 2 .scap file. /EFI/APPLE/FIRMWARE/MBP112_0138_B18_LOCKED.scap and /EFI/APPLE/EXTENSIONS/Firmware.scap They both have 2 files with GUID's that are present in the other, however the contents of each are different. The file with the GUID C3E36D09-8294-4B97-A857-D5288FE33E28 in /EFI/APPLE/FIRMWARE/MBP112_0138_B18_LOCKED.scap contains the text $IBIOS$ MBP112 88Z 0138 B18 1610201654 Copyright (c) 2005-2016 Apple Inc. All rights reserved. However the file with the GUID C3E36D09-8294-4B97-A857-D5288FE33E28 in /EFI/APPLE/EXTENSIONS/Firmware.scap contains the text N $IBIOS$ ROMEXT1 88Z 0002 B00 0710231738 What is the Firmware.scap file, and how come when I delete it, nothing changes except that it boots faster?

I am wondering if you can make an USB bootable without using a Bootable MacOS Monterey, Ventura, etc. I am asking you guys, if I have to add some special EFI partition with files in the USB or if I have to use some jailbreak to make an USB force bootable (if it exists), because since I am on a M1 Mac, USBs can't be bootable by adding a EFI folder in the base partition of the USB like the Intel Ones.

I see a post which is **12 years old**: https://apple.stackexchange.com/questions/57597/how-to-fix-broken-efi-partition?rq=1 **System**: Macbook Pro 2019 with Intel & T2, upgraded to Sonoma. **Objective**: Dual boot with T2Linux Fedora using https://t2linux.org/ **Trouble**: I accidentally deleted the EFI System Partition on MacOS. Now, I do have EFI for T2Linux (EFI NO NAME), but NOT with macOS. Now, with T2Linux Fedora, it requires first to update 'firmware.sh' in MacOS. **Deleted EFI in MacOS:** #: TYPE NAME SIZE IDENTIFIER 1: EFI EFI 314.6 MB disk0s1 **Current diskutil list: (1 TB partition: 400 GB for MacOS, and 600 GB for Linux):** me@mes-MacBook-Pro ~ % diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk0 1: Apple_APFS Container disk1 400.2 GB disk0s1 2: EFI NO NAME 629.1 MB disk0s2 3: Linux Filesystem 1.1 GB disk0s3 4: Linux Filesystem 598.3 GB disk0s4 **Current GPT Partition:** me@mes-MacBook-Pro ~ % sudo gpt -r show disk0 start size index contents 0 1 PMBR 1 1 Pri GPT header 2 4 Pri GPT table 6 76800 76806 97715079 1 GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC 97791885 115 97792000 153600 2 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B 97945600 262144 3 GPT part - 0FC63DAF-8483-4772-8E79-3D69D8477DE4 98207744 146068480 4 GPT part - 0FC63DAF-8483-4772-8E79-3D69D8477DE4 244276224 36 244276260 4 Sec GPT table 244276264 1 Sec GPT header **Output of Attempt to Install firmware.sh on MacOS:** me@mes-MacBook-Pro ~ % bash ~/Downloads/firmware.sh Detected macOS Mounting the EFI partition Volume on disk0s1 failed to mount because it appears to be an APFS Physical Store (or is the APFS Container already mounted?) See "diskutil apfs list" **EDIT: I tried the following Steps: But again, NO EFI was created:** # diskutil unmountDisk /dev/disk0 unmount of all voulmes on disk0 was successful # gpt remove -i 1 /dev/disk0 /dev/disk0s1 removed # gpt add -b 76806 -i 1 -s 97715079 -t 7C3457EF-0000-11AA-AA11-00306543ECAC /dev/disk0s1 /dev/disk0s1 added # diskutil repairVolume /dev/disk0s1 Finished file system repair on disk0s1 # diskutil mountDisk /dev/disk0s1 voulmes() mounted successfully **EDIT: Other Details (Asked by @David Anderson):** me@mes-MacBook-Pro ~ % sw_vers ProductName: macOS ProductVersion: 14.4.1 BuildVersion: 23E224 me@mes-MacBook-Pro ~ % csrutil status System Integrity Protection status: disabled. **I am NOT good in linux**. So, can some one guide me in very simple steps, please?

**System**: Macbook Pro 2019, Intel, T2, 16 GB RAM, No USB port (Using VIVA USB hub), Ventura 13.6.5 **Issues**: (1) Hash Volume Mismatch (2) Not re-installing MacOS (3) Bootable USB Drive is NOT showing up **Question**: How can I completely wipe out MacOS, and install Linux?

I am booting a retrogaming system (Recalbox, linux-based) on my Macbook Pro 2009 (Intel, El Capitan) from an SD card (FAT format). The SD card is currently displayed as "EFI boot" upon boot drive selection (*al*t key upon startup), as it currently displays "EFI boot". I would like to change that label ("RECALBOX", for example). I have been through many ressources online and tried the

command as advised here: https://apple.stackexchange.com/questions/388246/efi-partition-change-name-and-logo My version:

--folder /Volumes/RECALBOX/EFI/boot --label "RECALBOX"

It does create the expected hidden files in the folder .disk_label
.disk_label_2x but the default "EFI boot" label doesn't change in the boot selection on startup. Any ideas if I'm missing something? Thanks for your help!

I have a Macbook Pro Retina 13" (Early 2015) and I have a bootcamp partition with Windows 10 installed in it. Also, there is an Ubuntu Linux on another partition, so it’s a triple boot computer. I’m not using rEFInd, but the stock startup manager instead. I am switching operating systems using the option key at boot and it was all working fine until recently. The problem I am facing right now is that every time I turn my laptop on or try to switch operating systems using the option key the drive selection screen takes a long time to appear, like literally 20 to 30 seconds. This is not really normal because it used to be 2-3 seconds. Also, once the drive selection screen appears the mouse pointer just doesn't work or sometimes work un-reliably or extremely slowly. I can use the arrow keys in the keyboard to select the drives but the response is just too slow. Once i hit an arrow key it takes 15 to 20 seconds to register and move the selection, sometimes it doesn't respond at all. And then finally when I hit return it takes another half a minute or so to load up the boot sequence. After that the operating system works just fine. I also have GRUB on one of the partitions for loading Linux. When I select Linux in the Startup Manager drive selection screen the GRUB console starts and it works very slow as well: I have to type commands and wait 10 seconds for the letters to appear on the screen. Ubuntu itself works just fine. Could anyone please point me out on any possible causes of the problem? I will provide any additional info if you request. There is a very similar question , but it was solved by completely reinstalling everything. However I would like to find the real cause of the problem to be able to prevent it in future (my setup is kinda complex, and I don’t want to reinstall everything just to face this problem again in a month or two). **Update 1**: I have tried to reset NVRAM and SMC with no result. **Update 2**: I don't remember what exactly preceded the happening of this issue, but here are my thoughts: - Perhaps this happened after I installed "Paragon NTFS for Mac OS X" or "FUSE for OS X". I have both installed now and I use them to access Windows and Linux partitions - Maybe this happened after the hibernation of the Windows partition - It's possible that the issue happened after the system update, but it definitely happened long before the major update from El Capitan to Sierra. - The issue takes place not only in Startup Manager, but in any software that is running before the OS starts booting. Recovery, Hardware Diagnostics, Startup Manager, and even GRUB (which is on it's own partition) all work extremely laggy. If I don't hold any keys and let the macOS boot normally, then everything that occurs before the apple logo is taking much more time than it should. As soon the logo and progress bar appear - the lags are gone. Same with other OSes. The operating system is macOS Sierra 10.12.1 along with Windows 10 and Ubuntu. I have tried to run Apple hardware diagnostics (by holding down the D key at startup) and got this message: > There may be an issue with the SD card reader. Reference code VDC001 I've noticed that when I bought the laptop this test passed without any issues. I also tried to boot in Safe Mode, but nothing happened, except that the macOS GUI was glitchy and choppy while in safe mode. **Update 3**: I have found an interesting behaviour. The issue is gone just for one boot whenever I do these steps: 1. Boot into Ubuntu Live USB stick 2. Choose "Shut down" -> "Restart" from Ubuntu system menu 3. The subsequent boot goes without slugging, seems like the issue is gone, no matter which OS I choose this time. But the issue is back at the next boot. Also, if I choose to "Shut down" at the step 2, the subsequent boot is slugging like every other. What could be so special in Ubuntu live stick, that it cures the issue for one time? **Update 4** (2024) After I read this post again (thanks to upvoting) maybe the clue left in the comments is something worth investigating, if Ubuntu does not have the problem but macOS does after a 2nd reboot - it seems that either OS modifies something and my bet would be an EFI variable that is modified in a loop, those sit in NVRAM. To verify, optimally making dumps of the efi-store and compare maybe can finally nail this down. The issue was still present in 2021, and rEFInd author has a word about it as well: https://www.rodsbooks.com/refind/installing.html#sluggish

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.

I made a huge mistake. I resized my Bootcamp Windows Partition and messed up with my Mac partition; without any data, since my sister needed my backup hard drive for something urgent. To recover the data, I tried to install a new Mac partition onto the Bootcamp partition. Now I try to recover the original Mac partition. These are the outputs: Testdisk:

Partition                  Start        End    Size in sectors

 1 P EFI System                    40     409639     409600 [EF]
 2 P Windows Recovery Env      409640  400800263  400390624 [Ma]
 3 P Mac HFS                400800264  488965175   88164912 [Apple_HFS_Untitled_2]
 4 P Mac Boot               488965176  490234711    1269536 [Recovery HD]


diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *251.0 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2: DE94BBA4-06D1-4D40-A16A-BFD50179D6AC               205.0 GB   disk0s2
   3:                  Apple_HFS BOOTCAMP                45.1 GB    disk0s3
   4:                 Apple_Boot Recovery HD             650.0 MB   disk0s4
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *252.9 GB   disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:                  Apple_HFS Ohne Titel              252.5 GB   disk1s2
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *31.6 GB    disk2
   1:                 DOS_FAT_32 UNTITLED                31.6 GB    disk2s1
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *21.0 MB    disk3
   1:        Apple_partition_map                         32.3 KB    disk3s1
   2:                  Apple_HFS rEFIt                   20.9 MB    disk3s2


sudo gpt show disk0
Password:
      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  400390624      2  GPT part - DE94BBA4-06D1-4D40-A16A-BFD50179D6AC
  400800264   88164912      3  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  488965176    1269536      4  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  490234712          7         
  490234719         32         Sec GPT table
  490234751          1         Sec GPT header
Thomass-MacBook-Pro:~ Thomas$

2 days ago as I opened my laptop (mid 2012 MacBook Pro running Catalina), it booted in recovery mode. Disk utility was showing me my internal hard drive and its partitions : **disk0s1** and **BOOTCAMP**. The **disk0s1** was greyed out and when I tried to mount it, it would stay unmounted. So I asked Disk Utility to verify the hard drive and it gives me the error : "*This disk doesn’t contain an EFI system partition. If you want to start up your computer with this disk or include it in a RAID set, back up your data and partition this disk.*" So I try to boot in Windows (BOOTCAMP) but get stuck at a black loading screen with an error. Here is the output of various Terminal commands: diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *320.1 GB disk0 1: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF 279.9 GB disk0s1 2: Microsoft Basic Data BOOTCAMP 40.0 GB disk0s2 sudo gpt -r show disk0 start size index contents 0 1 PMBR 1 1 Pri GPT header 2 32 Pri GPT table 34 409606 409640 546609112 1 GPT part - FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF 547018752 78123008 2 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 625141760 655 625142415 32 Sec GPT table 625142447 1 Sec GPT header I really don't know how I lost this EFI partition, the computer was working 8 hours ago... After searching for an answer online it seems indeed possible to backup and restore the HD. Thus i install macOS on an external hard drive, and look for my data from there. But as you might have guessed, since **disk0s1** is unmounted I can't find any files... (except for the ones on BOOTCAMP, which sadly I don't care about). I then download 4 apps that pretend to be able to recover data from an unmounted HD ("iboysoftdatarecovery", "mac_drw", "StellarDataRecovery", "m3datarecovery"). They all end up launching a deep scan of the HD that takes 7 hours to complete, without even finding a single file (one of them did find around 30 system files or something) Can someone please give me any leads to recovering my data? I haven't backed up with Time Machine since March 2019 (8 months ago) and have most of my work and studies stored there.

I have a MacBook Pro (2013) running Sierra on the internal SSD. I’ve installed Debian12 onto an SD card. Upon boot (by holding down the Alt key) it doesn’t show an option of EFI Boot. But having flashed rEFIND-cd onto a USB, and once I plug it in, the Debian system on the SD card shows up and I am able to boot into it no problem. So what I want to do is install rEFInd onto that SD. Upon selecting to install rEFInd in Synaptic, I get a prompt asking : ” Configuring rEFIND - Automatically install rEFInd to the ESP?” I'm a bit hesitant on this and having searched the web I haven’t found a concrete answer… This thread sort of answers half of my question, but I'm still not exactly sure… https://apple.stackexchange.com/questions/188701/what-is-the-difference-between-hfs-and-efi-system-partition-esp My question is because I'm running Sierra on the internal SSD which has an EFI partition, if I choose to install rEFInd on to the ESP, will it not mess up the Mac OS EFI? Will it just install to the SD card Linux OS?

2 years ago, I installed Windows on a external SSD to be booted from my Mac. It used to work well. I would plug my external SDD, hold the option key at the beginning and chose if I wanted to boot on MacOS or on Windows (for windows, the name of the volume was EFI Boot). But today, something went wrong and the EFI Boot doesn't work anymore. When I choose it, the screen and the mouse freeze and I have to force a power off. The problem probably comes from the fact that I recently tried to install Linux on another partition of my external SDD. Although, I didn't want it, the EFI Boot file of Linux were placed in the EFI partition of my internal drive. In the end, I deleted Linux and the EFI File generated in the EFI partition of the internal drive. So technically, I didn't touch the EFI partition of my external SSD. But clearly something happened Beauce now it doesn't work anymore. Do you have any idea what happened? Is there a way to repair or recreate the EFI partition that would boot on the windows that is already installed on my external SSD? Thank you!

iOS devices have DFU mode, which enable one to completely reinstall the firmware and operating system. Do MacBook devices have something similar? Is the firmware automatically reinstalled upon an OS reinstallation?

I tried booting into EFI by holding ⌥ Option⌘ CommandFO My end goal is to enable nested VT-x in VirtualBox.