16
Using the ROM Monitor
OL-5997-02
How to Use the ROM Monitor—Typical Tasks
What to Do Next
If you want to configure the router to load a specified image at the next system reload or power-cycle,
see the following documents:
•
” chapter of the
Cisco IOS Configuration Fundamentals Command Reference
•
Cisco IOS Configuration Fundamentals and Network Management Configuration Guide
Modifying the Configuration Register (confreg)
This section describes how to modify the configuration register by using the
confreg
ROM monitor
command. You can also modify the configuration register setting from the Cisco IOS command-line
interface (CLI) by using the
config-register
command in global configuration mode. For more
information on the
config-register
command in global configuration mode and on using the
confreg
command in ROM monitor mode, see the
Cisco IOS Configuration Fundamentals Command Reference
.
Caution
Do not set the configuration register by using the
config-register
0x0
command after setting the baud
rate. To set the configuration register without affecting the baud rate, use the the current configuration
register setting by entering the
show ver | inc configuration
command and then replacing the last
(rightmost) number with a 0 in the configuration register command.
Table 1
xmodem Command Syntax Descriptions
Keyword or Argument
Description
-c
(Optional) Performs the download using 16-bit cyclic redundancy check
(CRC) error checking to validate packets. The default setting is 8-bit CRC.
-y
(Optional) Performs the download using Ymodem protocol. The default
setting is Xmodem protocol. The protocols differ as follows:
•
The Xmodem protocol supports a 128-block transfer size, whereas the
ymodem protocol supports a 1024-block transfer size.
•
The Ymodem protocol uses 16-bit CRC error checking to validate
each packet. Depending on the device that the software is being
downloaded from, the Xmodem protocol might not support this
function.
-r
(Optional) Image is loaded into DRAM for execution. The default setting
is to load the image into flash memory.
-x
(Optional) Image is loaded into DRAM without being executed.
destination-file-name
The name of the system image file or the system configuration file. For the
router to recognize it, the name of the configuration file must be
router_confg
.
