how grub.cfg under /boot/efi/EFI already has information about my root filesystem

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When I cat /boot/efi/EFI/ubuntu/grub.cfg I can see that it already has information about my root filesystem including root filesystem uuid.



I checked fstab and it is indeed uuid of a root filesystem.



I am trying to understand at what point it found and permanently wrote root filesystem uuid to a file in efi filesystem, and why it needs to do it in the first place, since esp is responsible for finding and loading a bootloader (grub), and it has nothing to do with actual root filesystem uuid.



I have read this How does a kernel mount the root partition? and from my understanding initramfs is used to find and mount root filesystem but then why root filesystem uuid is written into a file under efi filesystem?



search.fs_uuid 31592224-ea65-4f8d-bbb8-4d370f306d62 root 
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg





filesystems grub







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    up vote
    0
    down vote

    favorite












    When I cat /boot/efi/EFI/ubuntu/grub.cfg I can see that it already has information about my root filesystem including root filesystem uuid.



    I checked fstab and it is indeed uuid of a root filesystem.



    I am trying to understand at what point it found and permanently wrote root filesystem uuid to a file in efi filesystem, and why it needs to do it in the first place, since esp is responsible for finding and loading a bootloader (grub), and it has nothing to do with actual root filesystem uuid.



    I have read this How does a kernel mount the root partition? and from my understanding initramfs is used to find and mount root filesystem but then why root filesystem uuid is written into a file under efi filesystem?



    search.fs_uuid 31592224-ea65-4f8d-bbb8-4d370f306d62 root 
    set prefix=($root)'/boot/grub'
    configfile $prefix/grub.cfg





    filesystems grub







    share|improve this question

























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      When I cat /boot/efi/EFI/ubuntu/grub.cfg I can see that it already has information about my root filesystem including root filesystem uuid.



      I checked fstab and it is indeed uuid of a root filesystem.



      I am trying to understand at what point it found and permanently wrote root filesystem uuid to a file in efi filesystem, and why it needs to do it in the first place, since esp is responsible for finding and loading a bootloader (grub), and it has nothing to do with actual root filesystem uuid.



      I have read this How does a kernel mount the root partition? and from my understanding initramfs is used to find and mount root filesystem but then why root filesystem uuid is written into a file under efi filesystem?



      search.fs_uuid 31592224-ea65-4f8d-bbb8-4d370f306d62 root 
      set prefix=($root)'/boot/grub'
      configfile $prefix/grub.cfg





      filesystems grub







      share|improve this question















      When I cat /boot/efi/EFI/ubuntu/grub.cfg I can see that it already has information about my root filesystem including root filesystem uuid.



      I checked fstab and it is indeed uuid of a root filesystem.



      I am trying to understand at what point it found and permanently wrote root filesystem uuid to a file in efi filesystem, and why it needs to do it in the first place, since esp is responsible for finding and loading a bootloader (grub), and it has nothing to do with actual root filesystem uuid.



      I have read this How does a kernel mount the root partition? and from my understanding initramfs is used to find and mount root filesystem but then why root filesystem uuid is written into a file under efi filesystem?



      search.fs_uuid 31592224-ea65-4f8d-bbb8-4d370f306d62 root 
      set prefix=($root)'/boot/grub'
      configfile $prefix/grub.cfg





      filesystems grub




      filesystems grub






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited 9 mins ago

























      asked 15 mins ago









      MaverickD

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