Boot Option Variables Default Behavior; Removable Media Boot Behavior; Boot Via Simple File Protocol; Boot Mechanisms - Intel Extensible Firmware Interface Specification

list is used by the firmware's boot manager as the default load order for EFI
DriverOrder
drivers that it should explicitly load.

17.3 Boot Option Variables Default Behavior

The default state of globally-defined variables is firmware vendor specific. However the boot
options require a standard default behavior in the exceptional case that valid boot options are not
present on a platform. The default behavior must be invoked any time the
does not exist or only points to non-existent boot options.
If no valid boot options exist, the boot manager will enumerate all removable EFI media devices
followed by all fixed EFI media devices. The order within each group is undefined. These new
default boot options are not saved to non volatile storage. The boot manger will then attempt to
boot from each boot option. If the device supports the
the removable media boot behavior (see paragraph 17.4.1.1) is executed. Otherwise the firmware
will attempt to boot the device via the
It is expected that this default boot will load an operating system or a maintenance utility. If this is
an operating system setup program it is then responsible for setting the requisite environment
variables for subsequent boots. The platform firmware may also decide to recover or set to a
known set of boot options.

17.4 Boot Mechanisms

EFI can boot from a device using the
protocol. A device that supports the
system protocol for that device to be bootable. If a device does not wish to support a complete file
system it may produce a
directly. The Boot Manager will attempt to boot using the
first. If that fails, then the

17.4.1 Boot via Simple File Protocol

When booting via the
path that points to the device that "speaks" the
of the will point to the file name, including sub directories that contain the bootable
FilePath
image. If the file name is a null device path, the file name must be discovered on the media using
the rules defined for removable media devices with ambiguous file names (see paragraph 17.4.1.1).
The format of the file system specified by EFI is contained in Chapter 16. While the firmware must
produce a
SIMPLE_FILE_SYSTEM
can be abstracted with the

17.4.1.1 Removable Media Boot Behavior

On a removable media device it is not possible for the
including sub directories. The
not possibly be kept in sync with a media that can change at any time. A
Version 1.02
LOAD_FILE
SIMPLE_FILE_SYSTEM
SIMPLE_FILE_SYSTEM
LOAD_FILE_PROTOCOL
LOAD_FILE_PROTOCOL
SIMPLE_FILE_SYSTEM
SIMPLE_FILE_SYSTEM
protocol that understands the EFI file system, any file system
SIMPLE_FILE_SYSTEM
is stored in non volatile memory in the platform and can
FilePath
BootOrder
SIMPLE_FILE_SYSTEM
protocol .
protocol or the
protocol must materialize a file
which allows it to materialize an image
SIMPLE_FILE_SYSTEM
will be used.
protocol, the
FilePath
protocol. The next part
protocol interface.
to contain a file name,
FilePath
FilePath
12/12/00
Boot Manager
variable
protocol then
LOAD_FILE
protocol
will start with a device
for a
325