EFI 9.1 Boot Function
(4) DriverOrder variable
This variable specifies the actual loading sequence of the target drivers specified by the Driver#### variable.
(5) BootNext variable
This variable specifies the Boot#### variable used for booting by Boot Manager in the next boot processing.
Boot Manager clears the BootNext variable before control is passed to the boot target specified by the variable. If Boot Manager fails to boot the specified target boot program, boot processing continues according to the BootOrder variable.
9.1.2Boot processing order
If the BootNext variable is not found, Boot Manager selects Boot#### variables in the order specified by the BootOrder variable to execute boot processing.
If boot processing fails for any of the following reasons, Boot Manager continues processing with the next Boot#### variable specified in the BootOrder variable:
1The device or file specified by the Boot#### variable does not exist.
2A
3PXE boot is specified, but a cable is disconnected.
4PXE boot is specified, but the PXE server is not configured.
5A hard disk device is specified, but it contains no EFI partition.
6A
7A virtual floppy disk device is specified, but it contains no EFI partition.
8The file specified as the boot target fails during read processing.
9The file specified as the boot target is not in the EFI executable format.
10The Linux kernel does not exist.
11elilo is forcibly terminated during startup, such as because of [ESC] key input.
Remarks: If an error occurs after control is passed to the OS loader, the boot target is not switched and reset processing is executed using timer monitoring.