1
vote
1answer
57 views

Boot menu not working

So basically I can't boot from my ssd anymore. It just shows a grey screen with an error symbol. I can't get into target disk mode and none of the other boot shortcuts seem to be working either. When ...
0
votes
1answer
41 views

If I mess up the EFI System Partition, will Mac OS X be unbootable?

I forgot to make a backup of my EFI System Partition (ESP) and have installed grub onto it. If I happen to accidentally mess up the partition, will OS X be bootable? If not, how would I restore the ...
1
vote
0answers
506 views

Dual boot Ubuntu 14.04 on a MacBook Pro

so after a few hours of Google searching and too many headaches with a broken GPT, I've turned here. I have a 2012 MacBook Pro (9,2) that I want to dualboot OS X 10.9 and Ubuntu 14.04 on. I've read ...
0
votes
0answers
101 views

Efi Boot appears on BootCamp page

I'm new in this forum and I hope someone has an answer for my issue. Since yesterday my mac-book pro won't boot in Os X I have boot-camp on it If I turn on normally the apple logo, loading circle ...
0
votes
0answers
114 views

Mid-2012 Macbook Air, boot directly from MBR not from GPT

Ok, I have an end-goal of using rEFInd, windows, and linux installed on my macbook air. (info here: http://support.apple.com/kb/SP670 ) Windows cannot be installed onto a GPT partition, so I'll have ...
1
vote
0answers
347 views

Set EFI to boot Windows via (U)EFI one time

On my late 2012 Mac Mini, I have installed both Mac OS X Mavericks (with FileVault) and Windows 8.1 (natively, not via Bootcamp): /dev/disk0 #: TYPE NAME ...
1
vote
0answers
690 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 ...
4
votes
1answer
623 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 ...
1
vote
1answer
5k 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 ...
1
vote
3answers
1k views

How to enter boot menu without command key?

My Macbook air has a keyboard issue, the Z key does not work except upon startup where it becomes stuck for several seconds. This interferes with opening the boot menu on startup, because it detects ...
2
votes
1answer
224 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 ...
0
votes
2answers
4k views

How can I boot a 2012 Mac Mini off of a USB thumbdrive with CentOS on it?

I have a 2012 Mac Mini running OS X 10.7.3. On another PC, I have created a USB boot disc with CentOS 6.2 on it. The goal was to install CentOS onto the Mini. The USB drive is MBR partitioned and ...
2
votes
1answer
1k 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 ...
2
votes
1answer
907 views

MacBook Pro 2010 won't boot after EFI upgrade

I have updated my MacBook Pro (Core i5, early 2010) with system update to new EFI version, and now after startup it just shows the gray screen and doesen't react on keyboard (just plays the boot ...
0
votes
4answers
3k views

Lion won't start after EFI update

I installed the new EFI update for my MBA Mid 2011 (the software updater said it is recomended). The update went fine and restarted the mac afterwards. Then while booting the apple logo turns into a ...
3
votes
1answer
1k 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 ...