Cisco Catalyst 2960 Command Reference Manual page 661

Appendix A Catalyst 2960 Switch Bootloader Commands
unset
Use the unset bootloader command to reset one or more environment variables.
Syntax Description variable
Command Modes
Bootloader
Command History Release
12.2(25)FX
Usage Guidelines
OL-8604-04
unset variable ...
Use one of these keywords for variable:
MANUAL_BOOT—Decides whether the switch automatically or manually
boots up.
BOOT—Resets the list of executable files to try to load and execute when
automatically booting up. If the BOOT environment variable is not set, the
system attempts to load and execute the first executable image it can find by
using a recursive, depth-first search through the flash file system. If the
BOOT variable is set but the specified images cannot be loaded, the system
attempts to boot up the first bootable file that it can find in the flash file
system.
ENABLE_BREAK—Decides whether the automatic bootup process can be
interrupted by using the Break key on the console after the flash file system
has been initialized.
HELPER—A semicolon-separated list of loadable files to dynamically load
during the bootloader initialization. Helper files extend or patch the
functionality of the bootloader.
PS1—A string that is used as the command-line prompt in bootloader mode.
CONFIG_FILE—Resets the filename that Cisco IOS uses to read and write
a nonvolatile copy of the system configuration.
BAUD—Resets the rate in bits per second (bps) used for the console. The
Cisco IOS software inherits the baud rate setting from the bootloader and
continues to use this value unless the configuration file specifies another
setting.
HELPER_CONFIG_FILE—Resets the name of the configuration file to be
used by the Cisco IOS helper image. If this is not set, the file specified by the
CONFIG_FILE environment variable is used by all versions of Cisco IOS
that are loaded, including the helper image. This variable is used only for
internal development and testing.
Modification
This command was introduced.
Under normal circumstances, it is not necessary to alter the setting of the environment variables.
The MANUAL_BOOT environment variable can also be reset by using the no boot manual
global configuration command.
Catalyst 2960 Switch Command Reference
unset
A-23