SSD Paranoia & EFI System Partition

Discussion in 'Windows 10' started by embasie, Feb 24, 2016.

  1. embasie

    embasie MDL Novice

    Feb 14, 2013
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  2. blackdeathzc

    blackdeathzc MDL Novice

    Jul 21, 2009
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    It depends on what you have selected as boot device in your BIOS. Windows doesnt need an EFI partition on your Disk if it find an alternate device if im correct
     
  3. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
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    it finds the .efi file to boot from.
     
  4. embasie

    embasie MDL Novice

    Feb 14, 2013
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    My first boot is "Windows Boot Manager"
    With Ultra Fast Boot and Secured Boot enabled.
     
  5. embasie

    embasie MDL Novice

    Feb 14, 2013
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    The EFI System Partition has .efi files. But also does C:\Windows\Boot\

    Which EFI files do you think it's booting from? From the EFI System Parition or in C:\Windows\Boot\ ?
     
  6. abbodi1406

    abbodi1406 MDL KB0000001

    Feb 19, 2011
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    This "Boot" tag just indicate that it's the current OS partition, it doesn't mean it has the booting files or Windows Boot Manager
    the partition with "System" tag contain them
     
  7. Wazoo

    Wazoo MDL Senior Member

    Nov 5, 2013
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    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  8. laqk

    laqk MDL Novice

    Jan 22, 2011
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    The UEFI BIOS will scan all hard drives, USB drives and CDROM drives in the order specified in its setup. On each hard drive, it will check if it is a GPT formatted drive. If it is not, and legacy mode is disabled, it will move to the next drive. If it is GPT, it will then search for an ESP (EFI System Partition). If none is found, it will again move to the next drive in the list. If an ESP is found (it need not be the first partition on the disk), it will search for a file called BOOTX64.EFI (or BOOTIA32.EFI) in \EFI\BOOT. If this file is not found, again the disk will be considered non-bootable. If found, this file will be loaded in memory and executed, taking over booting process.

    USB drives can be either MBR, GPT or "superfloppy" and still be considered bootable, as long as they are formatted with the FAT file system (FAT12, FAT16 or FAT32) and have a file called BOOTX64.EFI (or BOOTIA32.EFI) in \EFI\BOOT.

    CDROMS need to be created with a special hidden "partition", but this partition must also contain a valid BOOTXXX.EFI file in \EFI\BOOT.

    Il all available drives are scanned in order, and none has a valid boot structure as described above, then UEFI boot fails and the BIOS enters console mode.

    So in response to the OP: In the situation you describe, yes, the UEFI BIOS first boots to your HDD that is GPT formatted and has an ESP in which it find a valid \EFI\BOOT\BOOTX64.EFI. This files then directs the system to \EFI\Microsoft\Bootmgr, which loads the BSD and continues the booting process. In your case, the BSD instructs Bootmgr that the Windows System partition in on your SSD (as can be shown by the command BCDEDIT), and system initialization continues from there.
     
  9. Flipp3r

    Flipp3r MDL Expert

    Feb 11, 2009
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    My question is why? What is wrong with the defaults? Why Why Why??? :death: