What is contained on the EFI System Partition?

The EFI System Partition (ESP) is a specialized partition on a data storage device that is used in systems with UEFI (Unified Extensible Firmware Interface). It primarily contains files necessary for the boot process of the operating system, including the first stage boot loader. This boot loader is crucial as it is the initial program that the UEFI firmware loads when the system starts, enabling the loading of the operating system.

The ESP typically includes the boot loaders for various operating systems installed on the system, as well as tools for system recovery and utilities that may be needed at startup. This setup is part of a modern boot architecture that allows for more flexible and efficient boot management compared to legacy BIOS systems.

In contrast, the Linux root file system is where the main operating system files reside, but it is not located on the EFI System Partition. Default swap space is managed separately by the Linux system to provide virtual memory, and it does not belong on the ESP. Similarly, the Linux default shell binaries are part of the root file system and not included in the EFI System Partition. Therefore, the designation of the first stage boot loader as part of the EFI System Partition accurately reflects its purpose and contents.