For early and/or buggy UEFI implementations the size of at least 512 MiB might be needed. To prevent interoperability issues with other operating systems it is recommend to make it at least 260 MiB. (Discuss in Talk:EFI system partition#Bump the recommended ESP size to 300 MiB) Reason: The recommended ESP size may need to be updated since Windows Setup creates a 300 MiB ESP on 4Kn disks. To confirm this is the ESP, mount it and check whether it contains a directory named EFI, if it does this is definitely the ESP. The list of partitions on the disk: Look for the EFI system partition in the list, it is usually at least 100 MiB in size and has the type EFI System or EFI (FAT-12/16/32).The disk's partition table: it indicates Disklabel type: gpt if the partition table is GPT or Disklabel type: dos if it is MBR.To find out the disk partition scheme and the system partition, use fdisk as root on the disk you want to boot from:
If you are installing Arch Linux on an UEFI-capable computer with an installed operating system, like Windows 10 for example, it is very likely that you already have an EFI system partition. 5.2 Firmware does not see the EFI directory.4.2.5.1 Replacing the above mkinitcpio hook.