B-6
Cisco 3700 Series Routers Hardware Installation Guide
OL-2180-08
Appendix B Using the ROM Monitor
ROM Monitor Command Descriptions
128 MB 32 MB 160 MB
128 MB 64 MB 192 MB
128 MB 128 MB 256 MB
rommon 2>
Other Useful ROM Monitor Commands
reset
or
i
—Resets and initializes the router, similar to power up.
Debugging Commands in the ROM Monitor
Most debugging commands are functional only when Cisco IOS software has crashed or failed to
initialize (boot). Debugging commands should normally be entered only under the direction of a Cisco
engineer. If you enter a debugging command and Cisco IOS crash information is not available, the
following error message appears:
“xxx: kernel context state is invalid, cannot proceed.”
The following ROM monitor debugging commands provide information about software failures:
•
stack
or
k
—Produces a stack trace.
•
context
—Displays processor context.
•
frame
—Displays an individual stack frame.
•
sysret
—Displays return information from the last booted system image. This information 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:
rommon 8>
sysret
System Return Info:
count: 19, reason: a SegV exception
pc:0x802b1040, error address: 0x802b1040
Stack Trace:
FP: 0x80908398, PC: 0x802b102c
FP: 0x809083b0, PC: 0x802b0b88
FP: 0x809083d8, PC: 0x8017039c
FP: 0x809083e8, PC: 0x8016f764
Configuration Register
The configuration register resides in NVRAM. You can view or modify the configuration register from
either the ROM monitor or the operating system software.
For procedures used to change the configuration register from the operating system, and for information
about configuration register settings, see
Appendix C, “Configuration Register.”
To modify the configuration register from the ROM monitor, use one of these methods:
•
Enter the
confreg
command by itself for menu mode. See the
“Modifying the Configuration Register
in Menu Mode”
section below.
•
Enter the
confreg
command plus the new hexadecimal value of the configuration register. See the
next section, “
Modifying the Configuration Register by Hexadecimal Entry
.”
