Debugging Commands; Configuration Register - Cisco EF4116 Hardware Installation And Maintenance Manual

Entering the ROM Monitor Program

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:
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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
of the configuration register when used in menu-driven mode.
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D-4 Cisco 4000 Series Hardware Installation and Maintenance
"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:
rommon 8 > sysret
System Return Info:
count: 19, reason: user break
pc:0x60043754, error address: 0x0
Stack Trace:
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).
rommon 9 > meminfo
Main memory size: 8 MB. Packet memory size: 4 MB
Available main memory starts at 0xa000e001, size 0x7f1fff
Packet memory starts at 0xa8000000
NVRAM size: 0x20000
The value is always interpreted as hex. The confreg utility will print a before and after view
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.