Specifications

56 Version 2.0
PATH support determines whether the PATH environment variable will be used to
determine the location of executables.
ALIAS support determines whether the ALIAS environment variable will be used to
determine alternate names for shell commands.
Interactive determines whether or not an interactive session can be started.
For more information on scripting, see UEFI Shell Script (Chapter 4).
F
or more information on processing of the startup.nsh file, please see UEFI Shell
Initialization (section 3.3).
T
he shell must remain compliant with its advertised shellsupport command
profile. There can be cases where a shell implementation may not want to expose
certain commands to all users. If a shell implementation wants to make a particular
command inaccessible to a particular user, they must properly interpret the command
request and return an appropriate return code, such as SHELL_SECURITY_VIOLATION.
3.2 Invocation
The UEFI Shell is a UEFI application. The UEFI Shell takes command-line options that
are null-terminated UCS-2 encoded strings. The syntax is:
shell.efi [ShellOpt-options] [options] [file-name [file-name-options]]
The command-line options are separated by the space or tab character. The options
are processed left-to-right retrieved from the LoadOptions field of the
EFI_LOADED_IMAGE_PROTOCOL.
The following table describes the standard command-line options.
Table 2 Standard Command Line Options
Option Description
file-name The name of a UEFI shell application or script to be executed after initialization
is complete. By default, if file-name is specified, then
-nostartup is implied.
Scripts are not supported by level 0.
file-name-
options
The command-line options that are passed to file-name when it is invoked.
options Options (from table X below) which control the initialization behavior of the
shell.
ShellOpt-
options
Options (from table X below) which control the initialization behavior of the
shell. These options are read from the EFI global variable “ShellOpt” and are
processed before options or file-name.
Table 3: UEFI Shell Invocation Options
-nostartup The default startup script startup.nsh will not be executed.
-noconsoleout Console output from the shell applications will not be displayed. This has
no effect for UEFI Shells that do not support an interactive mode.