Boot Linux in UEFI mode with an EFI boot program stored on the ESP.
What does UEFI do before the kernel?
UEFI follows boot entries to select and execute an EFI program, such as a bootloader, from the EFI System Partition.
Detailed explanation
Incorrect. systemd service dependencies are resolved later in userspace.
Correct. UEFI loads and executes the selected EFI program from the boot entry.
Incorrect. Signals to user processes occur after userspace starts.
Incorrect. /etc/fstab is processed after the kernel and init system start.
Try it yourself
An example you can run in a temporary verification environment.
test -d /sys/firmware/efi && echo UEFI || echo non-UEFI-or-hiddenExpected result
現在environmentでUEFI情報が公開されているかKey points
- UEFI
- ESP
- EFI application
Notes
- Environment: UEFI起動情報を読み取り確認
- Use read-only commands or a disposable Linux instance when checking boot metadata.
- Exact unit names and command output can vary slightly by distribution.
Foundation review
Place the operation
UEFI selects an EFI program from the ESP; service dependencies and filesystem mounts belong to later OS stages.
Check the side effect
Inspect EFI visibility without changing firmware variables or boot entries.