What is EFI boot?

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I had Yosemite on my MacBook Pro. I used Diskmaker X to create a bootable flash drive. Yesterday I did a clean install of El Capitan on my MBP. When I held down the "option" key, I saw "Macintosh HD" & the flash drive. I had minor problems installing El Capitan on my MBP but I figured them out & installed it.

This morning I tried to do a clean install of El Capitan on my Mac mini. It has Yosemite on it. I was able to cancel the installer & get to the Yosemite Desktop without screwing anything up. I started the disk utilities & the flash drive installer was listed. When I held down the "option" key, I saw "Macintosh HD", "Recovery" & "EFI boot". Why didn't I see the flash drive icon? What is EFI boot? What's going on? How do I get the flash drive icon to show up instead of EFI boot?

I read about "bless --info" so I did it & this is what came up:
finderinfo[0]:**** 49 => Blessed System Folder is /System/Library/CoreServices
finderinfo[1]: 3751013 => Blessed System File is /System/Library/CoreServices/boot.efi
finderinfo[2]:***** 0 => Open-folder linked list empty
finderinfo[3]:***** 0 => No alternate OS blessed file/folder
finderinfo[4]:***** 0 => Unused field unset
finderinfo[5]:**** 49 => OS X blessed folder is /System/Library/CoreServices
64-bit VSDB volume id:* 0x6500D7AE3A72109E

I don't understand why I was able to do a clean install of El Capitan on my MBP, but not on my mini. I didn't have the "EFI boot" problem when I did a clean install of Yosemite on my MBP & mini. Only the keyboard, mouse & Superdrive are plugged into the back of the mini. Should I unplug the Superdrive? Is it "confusing" OS X?
 

dtravis7


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The EFI Boot you are seeing is probably your Flash Drive. I have all my OSX installers on Flash drives and on most of my Macs under Option they show up as EFI Boot. Click on EFI Boot and it should start the installer.
 
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"probably"? "should start"?

I got my 1st Mac in June 2013. Before that, I "grew up" with Windows.

Please explain why the flash drive icon showed up when I did a clean install of El Capitan on my laptop, which previously had Yosemite, but "EFI boot" shows up instead of the flash drive icon when I try to do a clean install on my mini, which also previously had Yosemite.

Is it safe to delete the "boot.efi" file?

Can I "unbless" the folder?

I don't want to screw something up & have to take my mini to an Apple store & pay the store to do a clean install of El Capitan on my mini.
 
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When I use "get info" on the bootable flash drive I see a white circle with a multicolored "X" in it. When I open Finder, I see the installer drive, but it isn't labelled "EFI Boot". Yet when I plug in another flash drive, i see the usual flash drive icon. Interesting! You're probably right about it being the flash drive. It's just that I was expecting to see the flash drive icon when the option list came up on the mini since the flash drive icon showed up on my laptop. So, you can see my confusion & concern. I plugged in the bootable flash drive & then opened System Preferences & then clicked on "Startup Drive". The bootable flash drive wasn't listed. Should it have been?
 
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When you boot with Option held down, you're not running a full system, just enough to put up a menu.
The computer therefore doesn't know from icons or names yet. All it knows is there is a drive that's bootable so it puts it up as an option.
No idea why sometimes it knows what the name is and sometimes it doesn't. Possibly has to do with when you hit Option and how much system is loaded.
Since Macs boot from an EFI partition that's what it names it. EFI Boot.
Unless you have something else plugged in that's bootable, it's the flash drive.
Why you're getting a "NO" symbol when doing a get info I don't know. Try checking the drive with Disk Utility.
 
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I just tried an experiment. I restarted the mini WITHOUT the bootable flash drive & only the Macintosh HD & the Recovery partition showed up in the option list. Then I plugged the bootable flash drive directly into a USB port on the back of the mini & the white circle with the "X" slid in from the right. Since that was the only thing that I plugged in & since the white circle slid in after I plugged in the flash drive, I assume that the white circle IS the flash drive. What I don't understand is why the icons & the names are different. The laptop shows the flash drive icon & the name "OS X Installer". The mini shows the white circle with the "X" & the name "EFI boot". The white circle shows up on the Desktop on both the laptop & the mini. It also shows up in Finder on both the laptop & the mini. Could it be that the laptop & the mini boot differently? The laptop is a mid-2012 MBP & the mini is a mid-2012. Why doesn't the Superdrive show up as a boot option? Every time that Apple comes out with a new version of OS X, there's something different about how it does a clean boot. I also noticed that when El Capitan boots up, the screen is white. The last version of Yosemite booted up to a black screen.

So, I'll keep my fingers crossed when I do a clean install of El Capitan.

When do the powers-that-be at Apple inform their employees about the name of the next version of OS X? It's currently 10.11. I assume that it will eventually be 10.99. At the current rate of 1 per year, it will take 87 years to get to 10.99. I won't be around at that time! I wonder if the next version after 10.99 will be OS XI.
 
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Will they actually boot from this drive? Normally the "white circle and red X" means 'not gonna happen' or something's wrong.
Do you still have the downloaded installer? I'd make another install drive using the Terminal method instead of using DiskmakerX. See what happens.
 

dtravis7


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Craig, I don't think he saw that RED X but the OSX X with the selector arrow beneath it.

To the OP, I just tried a few Bootable Flash drives in a few different Macs. On my Minis they all said EFI boot. On my iMac 2 of them said OSX and 2 said the name of the drive. Depends on the Mac I guess. Maybe some load more system at that point. This is all with Option held down.

Also to answer the OPs other question, 10.11.0 and .1, ETC is OSX El Capitan. When the next actual VERSION of OSX comes out it will be 10.12.0 then .1, ETC. 10 means X, 11 after the first dot is the OS version and after the 2nd dot is the update (Sort of like a Windows Service Pack. They call them Point updates.
 
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YAY!!!
I did it!!!

I successfully did a clean install of El Capitan on my mini!!!
I didn't have the same steps as when I installed it on my laptop.
The installer wanted to upgrade, but I wanted a clean install. So, I had to back up & use Disk Utilities to nuke the hard drive. Then I did a clean install of El Capitan. The actual install didn't take as long on the mini as it did on the laptop.
I was a nervous wreck!

I can't figure out how to have Macintosh HD show up in Finder. The Superdrive does show up. How do I get the HD to show up in Finder?

I'm keeping my fingers crossed!
 
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Craig, I don't think he saw that RED X but the OSX X with the selector arrow beneath it.
It's a white circle with a big "X" that's blue on the top & red on the bottom.

On my Minis they all said EFI boot. On my iMac 2 of them said OSX and 2 said the name of the drive. Depends on the Mac I guess.
Interesting! So, my fear was unfounded. I've had a Mac since June 2013 & I'm still learning! That's why I frequent the forums.
 

dtravis7


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YAY!!!

I can't figure out how to have Macintosh HD show up in Finder. The Superdrive does show up. How do I get the HD to show up in Finder?

I'm keeping my fingers crossed!


Click on Finder in the Top Bar then Preferences under Finder. Select the General Tab. Be sure show Hard Discs is checked.
 
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I did it!
I successfully installed El Capitan on my mini.

The install steps on the mini aren't the same as on my laptop. That's confusing to an Apple newbie like me.
 

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