On Wed, 2025-07-09 at 20:11 -0500, Chris Adams wrote: > Once upon a time, Adam Williamson <adamw...@fedoraproject.org> said: > > On Wed, 2025-07-09 at 20:10 -0400, Sam Varshavchik wrote: > > > Chris Murphy writes: > > > > > > > I'm able to fix this with efibootmgr, but... what a swig of sour milk. > > > > > > That pretty much describes my kneejerk reaction about a decade ago when I > > > > > > first read about secure boot, and how great it is to have each boot stage > > > > > > signed by an all-mighty cert. > > > > Nothing Chris wrote about actually has anything to do with Secure Boot, > > really. It's just about how the UEFI boot manager works. > > Different Chris, but... it sounds like Windows gets a "fallback" > position for when the firmware has no boot entries; is there a way to > get Fedora into that position instead (in a dual-boot setup)? Or is it > a case of the firmware just explicitly looking for the Windows loader?
The fallback path is defined in the UEFI spec. It's essentially a magic location. On x86_64, it's EFI/BOOT/BOOTX64.EFI within the EFI system partition on a given disk; I don't recall offhand if there's a rule for which one to use if *multiple* EFI system partitions are present on a disk. The firmware will run whatever exists at that location. This is how removable media boot - it's how a Fedora USB stick or optical disc boots, when booting in UEFI mode - and also acts as a sort of 'recovery path' for permanent installs. Also some firmwares will let you say "just boot from this disk" (as opposed to picking an actual entry from the UEFI boot menu) for permanent disks as well as removable ones; that will trigger a fallback path boot. If Fedora's bootloader is occupying that spot on the disk, then Fedora will boot, and a special self-repair mode will kick in which will recreate the "Fedora" boot menu entry. If Windows' bootloader is occupying that spot, it'll boot Windows; I don't know if Windows does any kind of self-repair. Usually I'd expect Fedora's bootloader to be there on a dual boot install as Fedora gets installed after Windows, but there could be various reasons why Windows' bootloader would be there. -- Adam Williamson (he/him/his) Fedora QA Fedora Chat: @adamwill:fedora.im | Mastodon: @ad...@fosstodon.org https://www.happyassassin.net -- _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org 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/devel@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
