Intel Extensible Firmware Interface Specification page 342

Extensible Firmware Interface Specification
The variable contains an array of 3-character (8-bit ASCII characters)
LangCodes
ISO-639-2 language codes that the firmware can support. At initialization time the firmware
computes the supported languages and creates this data variable. Since the firmware creates this
value on each initialization, its contents are not stored in non-volatile memory. This value is
considered read-only.
The variable contains the 3-character (8 bit ASCII characters) ISO-639-2 language code that
Lang
the machine has been configured for. This value may be changed to any value supported by
LangCodes; however, the change does not take effect until the next boot. If the language code is
set to an unsupported value, the firmware will choose a supported default at initialization and set
to a supported value.
Lang
The variable contains a binary
Timeout
firmware will wait before initiating the original default boot selection. A value of 0 indicates that
the default boot selection is to be initiated immediately on boot. If the value is not present, or
contains the value of 0xFFFF then firmware will wait for user input before booting. This means the
default boot selection is not automatically started by the firmware.
The ConIn, ConOut, and
that defines the default device to use on boot. Changes to these values do not take effect until the
next boot. If the firmware can not resolve the device path, it is allowed to automatically replace the
value(s) as needed to provide a console for the system.
The ConInDev, ConOutDev, and
descriptor that defines all the possible default devices to use on boot. These variables are volatile,
and are set dynamically on every boot. ConIn, ConOut, and
of ConInDev, ConOutDev, and ErrOutDev.
Each variable contains an EFI_LOAD_OPTION. Each
Boot####
name "Boot" appended with a unique four digit hexadecimal number. For example, Boot0001,
Boot0002, Boot0A02, etc.
The variable contains an array of UINT16's that make up an ordered list of the
BootOrder
options. The first element in the array is the value for the first logical boot option, the
Boot####
second element is the value for the second logical boot option, etc. The
used by the firmware's boot manager as the default boot order.
The variable is a single
BootNext
first on the next boot. After the
used. To prevent loops, the boot manager deletes this variable before transferring control to the
pre-selected boot option.
The
BootCurrent
selected on the current boot.
Each
Driver####
appended with a unique number, for example Driver0001, Driver0002, etc.
The
DriverOrder
variable. The first element in the array is the value for the first logical driver load
Driver####
option, the second element is the value for the second logical driver load option, etc. The
324
UINT16
variables each contain an
ErrOut
ErrOutDev
that defines the
UINT16
boot option is tried the normal
BootNext
variable is a single
UINT16
variable contains an EFI_LOAD_OPTION. Each load option variable is
variable contains an array of UINT16's that make up an ordered list of the
12/12/00
that supplies the number of seconds that the
EFI_DEVICE_PATH
variables each contain an
are always proper subsets
ErrOut
Boot####
BootOrder
option that is to be tried
Boot####
BootOrder
that defines the
Boot####
descriptor
EFI_DEVICE_PATH
variable is the
order list is
list is
option that was
Version 1.02