Table Of Contents
Cisco 4500-M and Cisco 4700 ROM Monitor
Entering the ROM Monitor Program
Available ROM Monitor Commands
ROM Monitor Command Conventions
Debugging Commands
Configuration Register
Cisco 4500-M and Cisco 4700 ROM Monitor
This appendix describes the Cisco 4500-M and Cisco 4700 ROM monitor, the first software to run when the router is powered-up or reset. The Cisco 4500-M and Cisco 4700 ROM monitor supports more features than the familiar Cisco 4000-M ROM monitor. The ROM Monitor can help you isolate or rule out hardware problems encountered when installing your router. A summary of the ROM monitor diagnostic tests and command options is provided.
Entering the ROM Monitor Program
The ROM monitor diagnostics help initialize the processor hardware and boot the main operating system software. If you set the software configuration register (bits 3, 2, 1, and 0) to zero, you can start the router in the standalone ROM monitor. An example of the Cisco 4500-M and Cisco 4700 ROM monitor prompt follows:
To enable the Break key, and to default to booting at the ROM monitor while running the system software, reset the configuration register to 0x0 by entering configuration mode, and enter the configuration command following:
config-reg 0x0
The new configuration register value, 0x0, takes effect after the router is rebooted with the reload command. If you set the configuration to 0x0, you will have to manually boot the system from the console each time you reload the router.
Timesaver 
Break (system interrupt) is always enabled for 60 seconds after rebooting the system, regardless of whether break is configured to be off by setting the configuration register. During the 60-second window, you can break to the ROM monitor prompt.
Available ROM Monitor Commands
At the ROM monitor prompt, enter ? or help at the rommon 1 > prompt to display a list of available commands and options, as follows:
help monitor builtin command help
boot boot up an external process
dir list files in file system
dev list the device table
confreg configuration register utility
stack produce a stack trace
context display the context of a loaded image
frame print out a selected stack frame
sysret print out info from last system return
meminfo main memory information
Note
Further information about a command can be displayed by entering the command name with a -? option, which will cause the command usage message to be printed.
ROM Monitor Command Conventions
Following are ROM monitor command conventions:
•
Brackets [ ] denote an optional field. If a minus option is followed by a colon (for example: [-s:]) the user must provide an argument for the option.
•
A word in italics means that the user must fill in the appropriate information.
•
All of the built-in commands can be aborted (user interrupt signal) by pressing the <break> key at the console.
The following case-sensitive ROM monitor commands are among the most useful:
•
help—The help command prints a summary of the ROM monitor commands to the console screen.This is the same output as entering ?.
•
boot or b—Boot an image. The boot command with no arguments will boot the first image in boot flash. You can include an argument, filename, to specify a file to be booted over the network using the Trivial File Transfer Protocol (TFTP). The local device (see the description of b device following) can be specified by typing the device specifier (devid). If the specified device name is not recognized by the ROM monitor, the system will attempt to boot the image (imagename) from a network TFTP server. Do not insert a space between devid and imagename. Options to the boot command are -x, load image but do not execute, and -v, verbose. The form of the boot command follows:
boot [-xv] [devid][imagename]
b—Boots the default system software from ROM
b filename [host]—Boots using a network TFTP server. When a host is specified, either by name
or IP address, the boot command will boot from that source.
b flash:—Boots the first file in Flash memory
b device:—Boots the first file found in the Flash device. The Flash device specified can be either flash:, to boot the Cisco Internetwork Operating System (Cisco IOS), or bootflash:, to boot the boot image in Flash.
b device:name—An extension of the above command, allows you to specify a particular filename in the flash bank.
•
reset or i—Resets and initializes the system, similar to power-on.
•
dev—Lists boot device identifications on the router.
For example:
•
dir—Lists the files on the named device, dir device, where the device is flash or bootflash; lists the available files on that device.
For example:
File size Checksum File name
2229799 bytes (0x220627) 0x469e C4500-k
Debugging Commands
Most of the debugging commands are functional only when the Cisco IOS software has crashed or is aborted. If you enter the debug commands and Cisco IOS crash information is not available, the screen will display the following error message:
"xxx: kernel context state is invalid, can not proceed."
•
stack or k—Produces a stack trace.
•
context—Displays the processor context.
•
frame—Displays an individual stack frame.
•
sysret—Displays the return information from the last booted system image. This includes the reason for terminating the image, a stack dump of up to eight frames, and if an exception is involved, the address where the exception occurred.
For example:
count: 19, reason: user break
pc:0x60043754, error address: 0x0
FP: 0x80007e78, PC: 0x60043754
FP: 0x80007ed8, PC: 0x6001540c
FP: 0x80007ef8, PC: 0x600087f0
FP: 0x80007f18, PC: 0x80008734
•
meminfo—Displays the size in bytes, the starting address, the available range of the main memory, the starting point and size of packet memory, and the size of nonvolatile memory (NVRAM).
Main memory size: 8 MB. Packet memory size: 4 MB
Available main memory starts at 0xa000e001, size 0x7f1fff
Packet memory starts at 0xa8000000
Configuration Register
The configuration register resides in NVRAM. The configuration register is identical in operation to other Cisco routers. Enter confreg for the menu-driven system, or enter the new value of the register in hexadecimal.
Note
The value is always interpreted as hex. The confreg utility will print a before and after view of the configuration register when used in menu-driven mode.
•
confreg [hexnum]—Executing the confreg command with the argument hexnum will change the virtual configuration register to match the hex number specified. Without the argument, confreg will dump the contents of the virtual configuration register in English and allow the user to alter the contents. The user is prompted to change or keep the information held in each bit of the virtual configuration register. In either case the new virtual configuration register value is written into NVRAM and does not take effect until the user resets or power cycles the platform.
For example:
do you wish to change the configuration? y/n [n]: y
enable "diagnostic mode"? y/n [n]: y
enable "use net in IP bcast address"? y/n [n]:
enable "load rom after netboot fails"? y/n [n]:
enable "use all zero broadcast"? y/n [n]:
enable "break/abort has effect"? y/n [n]:
enable "ignore system config info"? y/n [n]:
change console baud rate? y/n [n]: y
enter rate: 0 = 9600, 1 = 4800, 2 = 1200, 3 = 2400 [0]: 0
change the boot characteristics? y/n [n]: y
1 = the boot helper image
do you wish to change the configuration? y/n [n]:
You must reset or power cycle for new config to take effect