A-4
Cisco VG202 and Cisco VG204 Voice Gateways Software Configuration Guide
OL-16191-01
Appendix A Using the ROM Monitor
Recovering Boot and System Images
Recovering Boot and System Images
If your voice gateway experiences difficulties and no longer contains a valid Cisco IOS software image
in flash memory, you can recover the Cisco IOS image using one of the following ROM monitor
commands:
•
xmodem
—Use this if the computer attached to your console has a terminal emulator that has
xmodem capability.
Using the xmodem Command
The
xmodem
command establishes a connection between a console and the voice gateway console port
for disaster recovery if both the boot and system images are erased from flash memory.
xmodem
[
filename
]—Establishes an xmodem connection between the console and the voice gateway.
The optional parameter argument
filename
specifies the source file containing the Cisco IOS image.
Other options include the following:
•
-c
—Use cyclic redundancy check (CRC-16).
•
-y
—Use Ymodem transfer protocol.
Note
The Cisco VG202 and Cisco VG204 voice gateways only support
-c
and
-y
.
Configuration Register
The virtual configuration register is in nonvolatile RAM (NVRAM) and has the same functionality as
other Cisco voice gateways. You can view or modify the virtual configuration register from either the
ROM monitor or the operating system software. Within the ROM monitor, you can change the
configuration register by entering the register value in hexadecimal format, or by allowing the ROM
monitor to prompt you for the setting of each bit.
meminfo
Lists the main memory information; for example:
rommon 6 >
meminfo
:
Main memory size: 128 MB.
Available main memory starts at 0x80018000
IO (packet) memory size: 5 percent of main memory
NVRAM size: 128 KB
boot commands
For more information about the ROM monitor boot commands, see the
Cisco IOS
Configuration Fundamentals and Network Management Guide
.
b
Boots the first image in flash memory.
b
flash:
[
filename
] Attempts to boot the image directly from the first partition of flash memory. If you
do not enter a filename, this command will boot this first image in flash memory.
Table A-1
Commonly Used ROM Monitor Commands (continued)
Command
Description
