512 emulation (512e) 4K physical sectors on the drive media with 512 byte logical configuration4K native (4Kn) 4K physical sectors on the drive media and 4K configuration reported to the host.4K-ready Host A host system which works equally well with legacy 512 as well as 512e hard disk drives.
Setting the boot flag by parted in a MBR partition marks that partition as bootable, while in a GPT partition it is marked as EFI System Partition
EFI System Partition
Code NameEF00 EFI System Partition
For Advanced Format 4K Native drives (4-KB-per-sector) drives, the
minimum size is 260 MB, due to a limitation of the FAT32 file format.
The minimum partition size of FAT32 drives is calculated as sector size
(4KB) x 65527 = 256 MB.
Advanced Format 512e drives are not affected by this limitation,
because their emulated sector size is 512 bytes. 512 bytes x 65527 = 32
MB, which is less than the 100 MB minimum size for this partition.
Although ESPs with size >=100 MiB and formatted as FAT32 are allowed
by Microsoft Windows and many Linux distros, Microsoft documentation
specifies that the minimum partition/volume size for FAT32 is 512 MiB.
Therefore an ESP should be at least 512 MiB size for maximum
compatibility. If you are using Linux EFISTUB booting, then you need to make sure
there is adequate space available for keeping the kernel and initramfs
files in the ESP.
It is recommended to use always GPT for UEFI boot as some UEFI firmwares do not allow UEFI-MBR boot.
The optimum size of the ESP varies depending on the number of OSes
you're installing and the Linux boot loader you choose to use. In
particular, ELILO and the Linux kernel's built-in EFI stub loader both
require that the Linux kernel and associated RAM disk be stored on the
ESP, so you should size the ESP much as you'd size a separate Linux
/boot partition (or larger) -- a minimum of 200 MiB, with 500 MiB being a
more desirable size. If you use GRUB as your boot loader, the kernel
can reside on a Linux partition, and the boot loader's needs are more
modest, so 100-200 MiB may be a reasonable size. Making your ESP larger
than necessary can increase your flexibility for future choices.
EFI Boot Stub makes it possible to boot a Linux kernel without the use of a conventional UEFI boot loader, such as GRUB 2 or elilo.
root # cp arch/x86/boot/bzImage /mnt/tmp/efi/boot/bootx64.efi
cp arch/x86/boot/bzImage /mnt/tmp/efi/boot/bootx64.efi