On Fri, Apr 19, 2024 at 9:31 AM Klaus-Peter Schrage via users <users@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > But, as Felix had proposed in his post, I dived a bit deeper into > efibootmgr (also new to me up to know), and found out that entries point > to PARTUUIDs, in my case: > FedoraHD(3,GPT,1ca6f5eb-cbea-11e9-a525-4ccc6ad8789c,0x24fc9800,0x32000)/\EFI\FEDORA\SHIM.EFI0000424f > Windows Boot Manager > HD(1,GPT,1ca6f5ea-cbea-11e9-a525-4ccc6ad8789c,0x800,0x24c60000)/\EFI\Microsoft\Boot\bootmgfw.efi0000424f > > And I found, that two partitions (EFI, Windows) on my third harddisk > have the same PARUUID: > > /dev/sdc1: LABEL="WIN" BLOCK_SIZE="512" UUID="A1C61D016294FB66" > TYPE="ntfs" PARTUUID="1ca6f5ea-cbea-11e9-a525-4ccc6ad8789c" > /dev/sdc3: UUID="BEAD-09C3" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI > System Partition" PARTUUID="1ca6f5eb-cbea-11e9-a525-4ccc6ad8789c" > I don't know if that really matters ... I don't think this matters for your Linux boot - no idea if it matters for your Windows boot. The basic process is EFI is using its variables (which you can examine with efibootmgr) to find a device and the file on the device to use for the boot. That should be on the *.efi files in /boot/efi/EFI/fedora/. That in term should load grub2, which will then use /boot/efi/EFI/fedora/grub.cfg. It then uses this to find the device with /boot/grub2/grub.cfg. As an example, here are the relevant bits from my system: [root@fubar ~]# efibootmgr BootCurrent: 0003 Timeout: 0 seconds BootOrder: 0003,0002 Boot0000* fubar HD(1,GPT,166f4bf1-c04a-447e-916a-2b0363cb6504,0x800,0x64000)/\EF I\fedora\shimx64.efi Boot0002* Fedora HD(1,GPT,166f4bf1-c04a-447e-916a-2b0363cb6504,0x800,0x12 c000)/\EFI\fedora\shimx64.efi Boot0003* Fedora HD(1,GPT,166f4bf1-c04a-447e-916a-2b0363cb6504,0x800,0x64 000)/\EFI\FEDORA\SHIMX64.EFI All 3 entries use "HD(1," so we don't need the device UUID, and all 3 have the same UUID and point to the file "\EFI\fedora\shimx64.efi". This is as expected as the system is single-boot, although I'm not really sure why I have *two* entries labelled "Fedora". Anyway... [root@fubar ~]# blkid | grep -i 166f4bf1-c04a-447e-916a-2b0363cb6504 /dev/nvme0n1p1: SEC_TYPE="msdos" UUID="21AA-D515" BLOCK_SIZE="512" TYPE="vfat" P ARTLABEL="EFI System Partition" PARTUUID="166f4bf1-c04a-447e-916a-2b0363cb6504" As expected, the EFI variables are pointing to the EFI partition (via PARTUUID). On that partition shimx64.efi will load grub while will use grub.cfg from the same directory. [root@fubar ~]# cat /boot/efi/EFI/fedora/grub.cfg search --no-floppy --fs-uuid --set=dev c5f18a2c-ee16-454e-b85d-6d7f03b86532 set prefix=($dev)/grub2 export $prefix configfile $prefix/grub.cfg [ Since you are getting a grub prompt, I think we can assume you are at least getting this far. ] The UUID maps to: [root@fubar ~]# blkid | grep -i c5f18a2c-ee16-454e-b85d-6d7f03b86532 /dev/nvme0n1p2: UUID="c5f18a2c-ee16-454e-b85d-6d7f03b86532" BLOCK_SIZE="512" TYP E="xfs" PARTLABEL="/boot" PARTUUID="26ff026c-ee27-441f-b6fd-4b38791e5dc8" So /boot/efi/EFI/fedora/grub.cfg points to the partition with /boot. --> Confirm your config points to the proper /boot partition. Now that grub knows how to find /boot, it can find /boot/grub2/grub.cfg. [root@fubar ~]# grep -- --fs-uuid /boot/grub2/grub.cfg search --no-floppy --fs-uuid --set=root c5f18a2c-ee16-454e-b85d-6d7f03b86532 search --no-floppy --fs-uuid --set=boot 21AA-D515 [root@fubar ~]# blkid | grep -i c5f18a2c-ee16-454e-b85d-6d7f03b86532 /dev/nvme0n1p2: UUID="c5f18a2c-ee16-454e-b85d-6d7f03b86532" BLOCK_SIZE="512" TYP E="xfs" PARTLABEL="/boot" PARTUUID="26ff026c-ee27-441f-b6fd-4b38791e5dc8" [root@fubar ~]# blkid | grep -i 21AA-D515 /dev/nvme0n1p1: SEC_TYPE="msdos" UUID="21AA-D515" BLOCK_SIZE="512" TYPE="vfat" P ARTLABEL="EFI System Partition" PARTUUID="166f4bf1-c04a-447e-916a-2b0363cb6504" --set=root has the correct UUID for /boot (in this case it appears "root" means the root of the grub config). --set=boot has the correct (device) UUID for the EFI partition. --> Confirm your entries are correct. Double-check file system type. If grub.cfg was created by grub2-mkconfig I would expect them to be correct. Now the grub config is going to be system-specific, but if you are getting this far you should have the grub menu that allows you to select which kernel/OS to boot. [ If no grub menu, you are not getting this far. ] Now grub loads the initramfs, etc. I *think* if there is a problem at this point you will get dropped into the dracut shell (as opposed to a grub shell). I should also mention that my system is Fedora 38, but until you get as far as loading initramfs I doubt that matters as long as you have EFI and grub2. -- _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
