• non_burglar@lemmy.world
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    4 months ago

    EFI can also live in firmware memory.

    You can pull the linux drive, boot from the windows drive, and if one of the firmware updates was for efi, windows will trash the entry for your Linux disk.

    This has happened for me many times, I had to use a grub rescue disk to rebuild the efi table.

    • Bitrot@lemmy.sdf.org
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      4 months ago

      The boot entries live in firmware yes, efibootmgr can create and remove them. The are pointers to the bootloader. Many systems can boot from the disk itself without the entry, the entry just makes it pretty (“Fedora” instead of NVME1).

        • Bitrot@lemmy.sdf.org
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          4 months ago

          Somewhat. One, a system can be bootable without the entries, so even if windows does the stupid and deletes them it isn’t the end of the world. It does depend on your specific firmware though.

          Also two, you can write them again with a single line in efibootmgr.

          This is very different than the old world where windows would delete your bootloader entirely. They live in the efi system partition instead - or at least the shim does- and typically every OS leaves the other ones alone (even Windows, except in this case).