Does a Linux OS need its own EFI partition

[Walter]

I have an iMac running High Sierra. I am using rEFInd to triple boot with macOS, Windows 10, and Fedora. When I mounted the ESP on the mac side (where rEFInd is also installed to), I noticed a microsoft folder in the EFI directory beside the BOOT directory for macOS; I also noticed the Windows installment does not have its own efi partition. When I installed Fedora 27, the installer insisted I create an efi partition to mount to /boot/efi.

Was this truely necessary? Could I move the efi files from the ESP dedicated to Fedora to the original ESP used by macOS, Windows 10, and rEFInd? If so, would there be any tangable benefits?

[MBWD]

I have a similar triple-boot setup, but without Windows. Fedora does require that you mount the EFI system partition (i.e., "ESP") at /boot/efi. But it does not require that this EFI partition be different for Mac/Windows/Other Linux. Stated differently, the information for all three OS's can all be placed on the same EFI system partition. You just need to tell Fedora (in /etc/fstab) to mount the EFI partition (on my Mac, it is at /dev/sda1, but I use UUID=<UUID for /dev/sda1>) at /boot/efi.

[Walter]

What files are required to move over to /dev/sda1? Does the folder structure matter? Currently I have a directory forBoot, Apple, and Microsoft; would I just make a Linux or Fedora directory and place all of the .efi files in that directory? What does your /boot/efi line in /etc/fstab look like? Thanks.

[MBWD]

I should caveat this reply with a statement that I am not an expert, at all. I do not fully understand all that is going on here on the ESP, and I had to tinker with it until it worked. That said, here you go.

My ESP (EFI system partition, mounted at /boot/efi in Fedora) looks like this:

/boot/efi/
├── bb4....................numbers..............11
│   ├── 4.14.5-300.fc27.x86_64
│   ├── 4.14.6-300.fc27.x86_64
│   └── 4.14.8-300.fc27.x86_64
├── EFI
│   ├── APPLE
│   │   ├── EXTENSIONS
│   │   └── FIRMWARE
│   ├── Boot
│   ├── fedora
│   │   ├── fonts
│   │   └── fw
│   ├── refind
│   │   ├── drivers_x64
│   │   ├── icons
│   │   │   └── licenses
│   │   ├── icons-backup
│   │   │   └── licenses
│   │   ├── keys
│   │   ├── regular-theme
│   │   │   └── icons
│   │   └── regular-theme-OLD
│   │       ├── font
│   │       └── icons
│   ├── tools
│   └── ubuntu
│       └── fw
├── System
│   └── Library
│       └── CoreServices
├── System Volume Information

And my /etc/fstab looks like this:

UUID=*ROOT DEVICE-UUID* /                       ext4    defaults        1 1
UUID=*UUID for ESP*          /boot/efi               vfat    umask=0077,shortname=winnt 0 2