Most distributions install a additional boot loader on an UEFI system. UEFIitself is a boot loader, it offers a menu to select different operatingsystems or individual kernels. Furthermore, the UEFI settings can easily bealtered with userspace tools like efibootmgr.Kernels since 3.3 support EFI_STUB, which means the kernel can be loadeddirectly from the UEFI. What's the reason distributions decide to use anadditional boot loader? Most tutorials on Linux/UEFI focus mainly on how toset up the additional boot loader (rEFInd, grub2, ELILO, etc.) instead ofbooting Linux with EFI_STUB.The only thing missing in the distributions is support. Since mostdistributions chain a second boot loader, the kernel is not added tothe UEFI boot menu, nor is it copied to the EFI system partition.Three scripts are sufficient to do all the magic. One which copiesthe initramfs to the ESP. A second one copies kernel to the ESP andcreates a new entry in the UEFI boot menu. The third script removesthe old kernel and initramfs from the ESP and deletes the UEFI bootmenu entry. This allows fully automatised kernel/initramfsupdates/purges without user interaction. I am using this approachsince more than a year and it has worked flawlessly.Why do most distributions use grub instead of EFI_STUB?Links:How to recreate EFI boot partition?EDIT: I'm not talking about removing grub support entirely but to offer achoice for those who want to use it for various reasons. Distributions couldprovide a package grub-efi for those who want to chain UEFI and grub and apackage efistub-boot which contain the scripts I mentioned above.
Why do most distributions chain UEFI and grub?
boot;grub2;boot loader;uefi