Modifying The Configuration Register (Confreg) - Cisco 2800 Series Manual

How to Use the ROM Monitor—Typical Tasks
Table 1
Keyword or Argument
-c
-y
-r
-x
destination-file-name
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:
•
•

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
Do not set the configuration register by using the config-register 0x0 command after setting the baud
Caution
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.
Using the ROM Monitor
16
xmodem Command Syntax Descriptions
Description
(Optional) Performs the download using 16-bit cyclic redundancy check
(CRC) error checking to validate packets. The default setting is 8-bit CRC.
(Optional) Performs the download using Ymodem protocol. The default
setting is Xmodem protocol. The protocols differ as follows:
•
•
(Optional) Image is loaded into DRAM for execution. The default setting
is to load the image into flash memory.
(Optional) Image is loaded into DRAM without being executed.
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.
"Booting Commands" chapter of the Cisco IOS Configuration Fundamentals Command Reference
Cisco IOS Configuration Fundamentals and Network Management Configuration Guide
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.
Cisco IOS Configuration Fundamentals Command Reference.
OL-5997-02