Firmware Partition.....

Discussion in 'macOS Mojave (10.14)' started by gpspad, Oct 2, 2018.

  1. gpspad macrumors 6502a

    Feb 4, 2014
    My parents 2012 Mac Mini is running High Sierra off of external SSD Drive. I was able to install High Sierra on it fine, and have experienced brio problems with the setup. I run CCC wo backup the computer very night, and may have had to clone the current SSD drive from a backup.

    When I attempt to install Mojave to I get n error messages that it cant install Mojave to the SSD drive because it does not have a Firmware Partition?

    But I did get High Sierra installed it a few months ago, and also have Mojave running off another headless mac mini booting off a SSD drive. So I was able to get Mojave to install and run off an extren usb ssd drive.

    I tried reinstalling High Sierra from the recovery portion, and got the same "disk needs a firmware portion" message. Any suggestion?

    The machine are not usable w/o OSX running off of a SSD drive.
  2. oatman13 macrumors regular

    Feb 14, 2013
    If you run `diskutil list` you will notice that you do not have an EFI Partition at disk0s1.
    Either you, or someone else that used your machine deleted it.

    Try booting to Recovery, running First Aid from disk utility, and see if that recreates it.
  3. gpspad thread starter macrumors 6502a

    Feb 4, 2014
    It seems like there is a EFI portion on disk0s1.

    Here are the results of the "diskutil list"....

    /dev/disk0 (external, physical):
    0: GUID_partition_scheme *500.1 GB disk0
    1: EFI EFI 209.7 MB disk0s1
    2: Apple_HFS Dad's Mac SSD Drive 499.2 GB disk0s2
    3: Apple_Boot Recovery HD 650.0 MB disk0s3

    I did have an issue for a while where the original HD wasn't booting. The internal HD was no longer seen on the diskutil program or when I booted from a USB stick with Sierra. That's when I added an external SSD drive. It was running fine, no problems then a month later, then my parents said it was running really slow.

    It turned out, a month later the old internal HD started working again and it was booting from it. I didn't have the guts to open the mini up and install the SSD so I just reformatted the internal HD because the system runs better on the SSD drive and I didn't think i could count on the old internal drive anymore.
  4. oatman13 macrumors regular

    Feb 14, 2013
    If you look it says (external, physical); the EFI System partition needs to be on the internal drive. It's fine that you have one on the external, but the internal drive needs to have a valid EFI System Partition; you should run First Aid on your internal drive.
  5. gpspad thread starter macrumors 6502a

    Feb 4, 2014
    Thanks, for the help.

    Suddenly, I am not seeing the internal HD any more in the diskutil tool now. Even when I boot from the rescue partition. It was there a couple of months ago and it does show when I use the "diskutil list" command.

    Is there another way to repair ir restore the internet HD?
    --- Post Merged, Oct 2, 2018 ---
    I went through a few startup options and it looks as if the internal drive is only showing up when I type “diskutil list”. When I boot into the recovery portition or try repairing the disk with the normal disktool it doesn’t show up.

    This was an intermittent problem I was never able to solve. I went around it by booting to an extrernal usb drive.

    Any suggestions?

    I could plug the external into another mac, and try updating it from there, but I will still have the issue where future installs will be hampered by the OS X install program not seeing a drive installed in the mini.

    I'd like to avoid brain surgery on the Mac mini at all costs. I already broke the status light on one when I did another mini I have.
  6. oatman13 macrumors regular

    Feb 14, 2013
    The EFI Firmware can only update using the EFI System Partition on the internal storage media. So even if you don't want to boot from it, you're still going to need a working drive in there to support firmware upgrades.

    If you can see it using `diskutil list` why don't you try:
    diskutil eraseDisk JHFS+ Internal /dev/disk#
    ^Replace "#" with the disk identifier for your internal drive.

    That command will erase the internal disk and create an EFI System partition, along with an HFS+ partition named "Internal". (Not that you really need the JHFS+ partition, but it will get created along for the ride).
  7. gpspad thread starter macrumors 6502a

    Feb 4, 2014
    I screwed up, the old internal hd, must be failing and is only intermittently recognized by the system. I had tried to run it off an external SSD drive, to avoid trying to install a new one.

    If I plug the ssd drive into another mini, and update the ssd drive, with Mojave. Then plug it into another machine, will it work?
  8. oatman13 macrumors regular

    Feb 14, 2013
    Yes your Mac will update, but booting your system with an older EFI Firmware could cause issues due to APFS support.
  9. gpspad thread starter macrumors 6502a

    Feb 4, 2014
    Thanks for all this help, I still don’t understand how the EFI firmware are connected to having an internal hard drive even though your not even booting from. I have seen so many posts of people running external usb ssd drives because they don’t have a way to upgrade or fix their internal hd and just use an external ssd drive to keep the Mac going.

    Maybe the new operating systems are making external ssd’s something you can’t do anymore?

    So is there any problems if I just put the ssd drive I am booting from now in the Mac mini and removed the old internal drive that’s not working?

    I have cloned ssd drives and later installed them into the Mac mini case, they worked fine, it now with the EFI stuff I am not sure if it will still work.
  10. oatman13, Oct 2, 2018
    Last edited: Oct 2, 2018

    oatman13 macrumors regular

    Feb 14, 2013
    This is how you should think of it...
    When you hit the power button your Mac loads a piece of firmware called the "EFI ROM", this code does not live on your internal drive; it's on a special chip on the logic board. That code is responsible for booting the operating system on whatever disk you want to boot.

    If you are not running the latest Mac EFI ROM, you could lack important security, and critical information about APFS changes.

    If you install on another Mac, and bring that SSD over to your mini, you could experience some really nasty bugs.
  11. crjackson2134 macrumors 601


    Mar 6, 2013
    Charlotte, NC
    Your mini needs a firmware upgrade. Mojave tries to install the upgrade for you. The installer looks for an EFI partition on the internal drive to validate your mini. Your internal drive is defective and can’t validate, so the installer gives you an error that it cannot find the needed partition. It must validate from an internal drive only AFAIK. This is the same or similar requirement for the nMP 6,1 as well.

    Do you understand?
  12. gpspad thread starter macrumors 6502a

    Feb 4, 2014
    Yes, I think so....

    If I install a non OEM hard drive with a EFI partition, will Mojave validate the mini?

    I guess not installing the SSD drive only pushed the problem down the road.

    Thanks for all the help.
  13. oatman13 macrumors regular

    Feb 14, 2013
    You can install any drive you want as long as its plugged into the logic board on the mini, but after you install it erase the disk with diskutil; that will create the EFI System Partition.

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12 October 2, 2018