Booting with MBR in UEFI (No CSM mode at all)?

Discussion in 'PC Hardware' started by ceo54, May 5, 2020.

  1. ceo54

    ceo54 MDL Addicted

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  2. Enthousiast

    Enthousiast MDL Tester

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    Windows 8.1 and 10 can run on pure EFI, no modifications needed.
     
  3. ceo54

    ceo54 MDL Addicted

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    It did not wok. No boot device found. Thanks for the reaction though.

    Also, what is "Boot from EFI file" ??
     
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  4. Enthousiast

    Enthousiast MDL Tester

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    Maybe that's something at your end (improper install medium configuration, etcetc..), from windows 8 and up, pure efi is natively supported.
     
  5. ceo54

    ceo54 MDL Addicted

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    Possibly yes, I can boot my WinPE USB in UEFI mode even though it's MBR.

    Thanks for the help.
     
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  6. Enthousiast

    Enthousiast MDL Tester

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    For USB installer to be able to boot on a pure EFI system (and not using any third party tools), it has to be FAT32 formatted, it will boot EFI and Legacy BIOS setups.
     
  7. Hadron-Curious

    Hadron-Curious MDL Guru

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    Make sure you formatted your bootable USB to FAT32 and use Rufus to create a EFI bootable USB(must be in FAT32). Go to your BIOS and select UEFI option. You must also partition the internal hard drive GPT.
     
  8. Flipp3r

    Flipp3r MDL Guru

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    Boot UEFI Shell (Shellx64.efi). Mainly used to flash your bios/uefi & other firmware. ie, ec for notebooks, fw for raid cards, etc...
     
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  9. murphy78

    murphy78 MDL DISM Enthusiast

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    Rufus for the last few years I think has multi-partition hacks that let you have the MBR fat32 partition to boot and another partition for large 4gb+ files.
    Just mentioning this for the people that might not know. You most likely already know since you deal with the Windows releases constantly.
     
  10. Enthousiast

    Enthousiast MDL Tester

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    That's why i specifically mentioned "(not using any third party tools)", when someone mentions one tool, there will be multiple other tools advertised, not going into that kind of discussions:)
     
  11. istighfar

    istighfar MDL Junior Member

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    Rufus now allows to boot from UEFI using NTFS.
    People always used to think that UEFI works only with FAT32. False!!!
    That's what they want people to believe but in reality you just need to find the driver of the file system that your firmware uses so that UEFI can boot from it.
     
  12. Enthousiast

    Enthousiast MDL Tester

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    Afaik, what @murphy posted about Rufus creating an EFI bootable FAT32 partition and redirects to a ntfs partition on which the actual install files are placed.

    There exist some hardware that allows to boot EFI from plain NTFS installmedia, iirc, because the hw manufacturer had a driver available for it, don't remember the specifics.
     
  13. murphy78

    murphy78 MDL DISM Enthusiast

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    I think the fat32 limit is only necessary if you use windows loaders like the ones included with setup media. I don't think I ever found a 3rd party loader for windows that satisfied me. About the best thing I found was doing the trick to make 2 partitions that rufus and others do. It's not official by MS or anything, but it at least uses the official MS loaders.
     
  14. ceo54

    ceo54 MDL Addicted

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    Got it. Thanks
     
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  15. Flipp3r

    Flipp3r MDL Guru

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    I know the MSI notebooks have a ntfs driver built into their UEFI. MSI recovery creates a usb that's straight ntfs & bootable.
    If you boot a rufus created usb key on the notebook, you'll see rufus checks for the driver in uefi & skips loading it's own...
    I think Gigabyte may have it as well.
     
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  16. Hadron-Curious

    Hadron-Curious MDL Guru

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    Yes, it does . But, for Master Boot Record to work it is advisable to use FAT32 else the system is going to encounter booting issue.
     
  17. ceo54

    ceo54 MDL Addicted

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    MBR boots just fine with NTFS, why should anyone use FAT32 ?
     
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  18. Hadron-Curious

    Hadron-Curious MDL Guru

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    That is for the simple reason you will be missing some UEFI features from CPU independent drivers mostly. In fact, you are basically using the legacy BIOS when MBR is running on NTFS.

    I have come across a situation where BIOS couldn't locate the internal HDD but boot from external bootable USB despite the internal HDD is prioritized to be the first booting configuration when MBR is running on NTFS.
     
  19. ceo54

    ceo54 MDL Addicted

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    I got nothing against UEFI, but whosoever forgot to make addition for NTFS driver mandatory was a jerk, looser and a leech.
     
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