Questions tagged [efi]

Extensible Firmware Interface is a specification that defines a software interface between an operating system and platform firmware

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5answers
200k views

MacBook Pro: How to disable discrete GPU permanently from EFI?

I'd like to disable the NVidia GTX 750M GPU on my MacBook Pro 15" (Retina, Mid 2014, Mac OS X 10.10 Yosemite). I know I can use GfxCardStatus but I read I could have a more permanent solution by ...
24
votes
5answers
151k views

How to fix broken EFI partition?

I have an iMac running OSX Lion. I also installed bootcamp and Windows 7. During the install of Windows 7 I wasn't paying complete attention and deleted and formatted the EFI partition. I didn't ...
21
votes
4answers
16k views

Is a hardware-based full disk encryption possible on a Mac?

Is it possible to use hardware-based full disk encryption (perhaps on a Samsung 840 Pro SSD) on a Mac, specifically a Macbook Pro 8,2? If so, how? My understanding is that this will be handled in the ...
13
votes
2answers
4k views

Hide “disk password” login option at EFI (Filevault) login screen

I encrypted my volume before installation and have added my user as FileVault user afterwards. Now I can login with either the disk password or my user login password at the EFI (Filevault) login ...
12
votes
2answers
3k views

Is there any way to manually bless firmware when main disk is external?

My iMac (mid 2010) keeps pestering me to upgrade my EFI firmware to 1.8. Sadly, no matter how many times I try to to upgrade the EFI (from the manual install, or the auto update), it does not seem to ...
10
votes
1answer
23k views

How to fix broken GPT, GUID and unmountable, no type volumes?

I have a Macbook Pro with retina, Yosemite and 500GB hard drive. I tried to install Windows using Bootcamp and accidentally deleted a partition, now my Mac cannot boot anymore. This is the output from ...
10
votes
1answer
17k views

How to downgrade EFI firmware back to version 1.6

I'm trying to get a SATA III hard drive to work in my MacbookPro5,1. I think I've finally figured out that if I downgrade the EFI firmware to version 1.6, my computer will negotiate the link at SATA 1 ...
9
votes
4answers
4k views

How can the average user easily validate the integrity of their Mac's firmware?

How can the average user easily validate the integrity of their Mac's firmware? Before you downvote this question or lecture me on how I am paranoid and no one should ever need to do that, please ...
8
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2answers
8k views

Why does Disk Utility create EFI partitions on external disks?

A technical told me about the EFI partition that... ...it's only there in case your computer will do an EFI update so the update files can be loaded onto the EFI partition. This is consistant with ...
8
votes
3answers
27k views

Keyboard and touchpad are not working when booting from live USB

I have a MacBook Pro (mid 2017, 13", no Touch Bar) and I want to create Linux live USB. However, keyboard and trackpad are not working when I'm booting Linux OS from live USB. I'm able to select EFI ...
8
votes
1answer
3k views

How to clean boot menu and check/clean mbr

I had successfully installed Windows 8 Consumer Preview on my mac mini (bootcamp install) but Windows crashed during the upgrade to Release Preview and I removed it a result. But there seem to be some ...
7
votes
4answers
46k views

How to update latest MacBook pro EFI firmware manually?

In short, the firmware cannot be updated either by upgrading macOS to High Sierra or by bless manually. Here comes the detail. My MacBook pro info: Attempt 1 - update it by updating macOS from 10.12....
7
votes
1answer
5k views

How can I triple boot MacOS Catalina , Ubuntu 18.04, and Windows 10

I currently use the mid-2014 MacBook Pro. I have read the similar questions asked but as I don't have much technical knowledge I thought I should create a new question. Device History I had ...
6
votes
3answers
5k views

How to create linux USB discs that do work on Apple Macs?

It seems that there are several problems releated to incompatibilities between Apple-EFI and UEFI that do prevent Apple users from easily using USB drives to install or even run other operating ...
6
votes
4answers
51k views

How can I install the newest EFI firmware upgrade from El Capitan?

I've got an early 2011 MacBook Pro (8,1) and I am trying to install the newest EFI firmware upgrade, however it only supports 10.8.5 and 10.9.5. Unfortunately I have no clue as to what the best ...
5
votes
3answers
15k views

GRUB 2 error – “fb: switching to radeondrmfb from EFI VGA”

Whenever I try to boot Arch, Mint or Debian Linux from a USB stick using GRUB 2 on my Mac with compatibility mode, it freezes on this error (given in the question title). I've tried every available, ...
5
votes
1answer
897 views

Replacing macOS with elementary OS. Computer boots normally into elementary OS, but boot menu (option key on boot) doesn't show anything

I want to replace macOS with elementary OS on a Mac. I formated the entire hard disk, inserted the elementary OS bootable USB, selected EFI boot on the boot loader (only option) and installed ...
5
votes
1answer
15k views

How to transform an Apple Mac Mini intro a reliable Ubuntu Server?

This question is about what steps are needed for transforming an Apple Mac Mini into an Ubuntu server. Here are some areas: installing Ubuntu and making it to be bootable from EFI by default enabing ...
5
votes
3answers
10k views

How to boot and install Linux or BSD on a 2007 MacBook White via USB?

I have an old MacBook white (Model 2,1 mid-late 2007) which won't upgrade beyond Snow Leopard (OS X 10.6). I have previously installed Debian with a dual boot by using rEFIt and booting from a DVD ...
5
votes
1answer
8k views

Disk Utility says: “Error: This disk doesn't contain an EFI system partition.”

After a clean install of Lion, followed by partitioning which again was followed by a installation of Ubuntu, I noticed some error messages of Disk Utitity. When verifying the volume I get told that ...
4
votes
1answer
27k views

What does boot.efi actually do?

I understand that when a Mac's EFI system runs, it locates the file boot.efi in the /System/Library/CoreServices/ (blessed) directory and runs this as an EFI application (subverting a large part of ...
4
votes
2answers
15k views

Unsupported hack or workaround to get 64-bit OS X to install on a MacBook Pro having only 32-bit EFI?

I want to install the 64-bit OS X 10.7 on my MacbookPro 2,1, which has a 64-bit processor, but only 32-bit EFI and Kernel Boot mode. I know that this is not officially supported, but I assume there ...
4
votes
11answers
6k views

OSX Boot drive selection screen is slow, un-responsive and takes forever to load in Macbook Pro (early 2015)

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 ...
4
votes
1answer
104 views

Mac Partition won't boot after Bootcamp Partition Resize

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 ...
4
votes
3answers
7k views

Windows 10 EFI on MacPro 4,1 -> 5,1

I'm attempting an EFI install of Windows 10 on a 2009 (4,1) Mac Pro firmware upgraded to 5,1. I'm running High Sierra, and installing Windows 10 on a second partition on the same disk. I have no ...
4
votes
1answer
3k views

How do I boot into the EFI firmware shell?

I'd like to experiment with the EFI shell on a MacBook Pro 2010 model. I am unable to find the keyboard sequence to hold on boot. Does someone know what the sequence is, do I need to boot from my ...
4
votes
1answer
3k views

What is /Volumes/firmwaresyncd?

I keep seeing this in my logs: > 10/5/15 3:45:16.532 AM deleted[366]: normalizeUserMountpoint:738 > volRoot failed for /Volumes/firmwaresyncd.G3PNKw What is it? Is it related to the firmware ...
4
votes
1answer
2k views

Trapped: MacBook always shuts down during EFI SMC Update 1.8. Can't boot. How to remove updater from boot routine?

MacBook Pro i7 Mid-2012 (MacBookPro9,2) running Mac OS X 10.8.5: Downloaded the "offered" EFI SMC Update 1.8 through the AppStore Updates. MacBook restarted, grey progress bar appears w/ spinning ...
4
votes
1answer
3k views

Understanding firmware.scap

So, I recently acquired an old MacbookPro (v.5,4 mid 2009). I decided to create an Arch linux partition, and thus began my adventure... While installing rEFInd (the maintained fork of rEFIt), I ended ...
4
votes
0answers
520 views

Macbook Air (mid 2012) Efi Firmware Downgrade –to original

I want to bring back my beloved Macbook Air 2012 (MBA5,2) to its 'original firmware'. I have identified the file as MBA51_00EF_B01.scap, which I extracted using unpkg over the downloadable offered by ...
4
votes
0answers
53 views

Old Mac Pro: Windows? GPUs?

I recently got an old Mac Pro 1,1 for free, and was wondering what's necessary to get it running Windows. I know that you needed Boot Camp before Windows 7, because it didn't support the EFI, but ...
3
votes
1answer
8k views

Not able to mount EFI partition with diskutil after installing Ubuntu

I installed Ubuntu as dualboot for a specific task to a 30 GB partition. It worked, however I found out I could do the same thing in macOS, so I removed the 30 GB partition. I also wanted to remove ...
3
votes
1answer
5k views

Installing Ubuntu 16.04 server on Mac Mini 2006

I have liberated an old 2006 Mac Mini (Model: A1176) from being thrown away and wanted to use it as a Time Capsule for my other Macs. To do this, I want to install Ubuntu server 16.04 LTS to roll my ...
3
votes
1answer
1k views

What cool things can you do if you hack EFI

I think I'm right in thinking Intel Macs use EFI. I heard rumours that you can create low-level password protection and even install a shell. Info is sparse and limited. Have any power users hacked ...
3
votes
3answers
7k views

Efibootmgr command for OS X

I have successfully been able to install Linux Mint on my Mac. The only issue is I cannot select the boot partition holding option. To fix it I booted into linux and ran sudo efibootmgr -o 1,80. This ...
3
votes
1answer
495 views

Does Windows, running on latest Apple computers, see boot disk partitioned as MBR or GPT?

From my understanding, the newest apple computers boot Windows in EFI mode. Traditionally, Windows has seen the boot disk as an MBR partitioned disk. In fact, the boot disk (i.e. /dev/disk0) has aways ...
3
votes
1answer
25k views

Disable wireless network card Mac OS X [duplicate]

I wonder if there is any way, how to turn off / disable the wireless network interface or driver, so I cannot connect to WiFi from running OS. I have MacBook Pro with OS X Mavericks. The reason for ...
3
votes
1answer
91 views

*Complete* recipe for installing single-boot Linux

In this question I summarize a complete recipe for installing single-boot (this should be simple!) Ubuntu 18.04 LTS on an Early-2011 Macbook 17". But it has an error. If you are doing an identical or ...
3
votes
2answers
1k views

Can't update my Macbook firmware

Here is my very sad story. I have a Macbook pro 13" retina early 2015 (MB 12,1). My bootrom version is MBP121.0167.B07 and according to this ( https://docs.google.com/spreadsheets/d/...
3
votes
1answer
4k views

How do I restore my missing partition and install Windows 7 64-bit?

I previously had a Windows 7 32-bit installed on my Mac using Boot Camp Assistant. I recently upgraded it to Windows 10 (followed Microsoft update message), but later after I saw some drivers are ...
3
votes
2answers
8k views

Any solution to bootcamp windows 8.1 with macbook pro 15" 2010?

This question may at first glance seem to be a duplicate but I am asking for an update and clarification to an unsolved problem. After extensively scanning the web, it seems that the consensus is ...
3
votes
2answers
6k views

How do I keep the Recovery HD and EFI partitions from automatically mounting on my MacBook Air?

I've set Finder preferences on my MacBook Air running OS X 10.9.1 to show everything on my desktop: I've noticed that storage partitions called Recovery HD and EFI appear there: What are they? Is ...
3
votes
1answer
267 views

Late-2013 rMBP able to install & boot Win8 using EFI?

I've previously installed Win7 (and then upgraded to 8) via Bootcamp, but I've been looking around some forums recently regarding running Win8 natively. I now have the impression that the latest-gen ...
3
votes
1answer
2k views

OS X Mountain Lion does not boot after the creation of a Fusion Drive

I have followed a guide to set up the core storage logical volume to use one SSD and one HDD. Since then, I have encountered multiple errors such as: 69822 Couldn’t rediscover disk after operation ...
3
votes
1answer
352 views

FreeBSD Install DVD corrupted my Mac OS X harddisk

Recently, I have tried a FreeBSD 7.4 i386 Install DVD, just to see some screens of FreeBSD on my Mac mini Intel 2006. I was going to see (to remember) just several dialog screen of and perhaps I would ...
3
votes
1answer
3k views

What can slow down/How can I speed up the pre-kernel boot steps?

I've got a late 2007 Macbook Pro with 4 GB of RAM and an SSD. I am running Boot Camp and have an OptiBay. I have partitioned the SSD and secondary drive to devote half of each to Lion and half to ...
3
votes
1answer
411 views

MacBook Pro will not wake from sleep after installing third party application

I installed an application called Air Parrot that uses air play with an Apple tv to mirror or extend the desktop. I noticed that after I installed it, I am no longer able to wake my Mac from sleep. ...
2
votes
1answer
187 views

How to resolve messed up GPT (FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF) from Ubuntu without data loss

I was having Ubuntu installed along with MacOS Catalina. I need windows for project work so I decided to create a partition and flash windows in it... Doing this I messed up and there was showing no ...
2
votes
1answer
2k views

edit efivars on MacOSX

On Linux, I can edit the efivars of my MacBookPro via /sys/firmware/efi/efivars/. E.g. here is a description to disable the AMD GPU via the efivars, which basically is this on Linux: printf "\x07\x00\...
2
votes
1answer
7k views

Is it possible to reinstall MacBook firmware?

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 ...