Cisco 3725 Software Configuration Guide - Page 182

Entering the ROM Monitor Mode Appendix C Using the ROM Monitor Tip From the Cisco IOS software, you can configure the router to automatically enter the ROM monitor mode the next time the router boots by setting virtual configuration register bits 3, 2, 1, and 0 to zero. From the console, enter the following configuration command: configuration-register 0x0 The new configuration register value, 0x0, is effective after the router is rebooted with the reload command. The router remains in the ROM monitor and does not boot the operating system. As long as the configuration register value remains 0x0, you must manually boot the operating system from the console. Refer to the boot command in the section "Command Descriptions" later in this appendix. ROM Monitor Commands Enter ? or help at the ROM monitor mode prompt to display a list of available commands. For example: rommon 1 > alias boot break confreg cont context cookie dev dir dis dnld frame help history meminfo repeat reset set stack sync sysret tftpdnld unalias unset xmodem rommon 2 > ? set and display aliases command boot up an external process set/show/clear the breakpoint configuration register utility continue executing a downloaded image display the context of a loaded image display contents of cookie PROM in hex list the device table list files in the file system display instruction stream serial download a program module print out a selected stack frame monitor builtin command help monitor command history main memory information repeat a monitor command system reset display the monitor variables produce a stack trace write monitor environment to NVRAM print out info from last system return tftp image download unset an alias unset a monitor variable x/ymodem image download Note You can abort any command by pressing the Break key at the console. Note The command tftpdnld is present in the Cisco 2600 series routers only. Note The command upgrade rom-monitor is present in the Cisco 3700 series routers only. Software Configuration Guide for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers C-2 OL-1957-04