Table of Contents
Advertisement
Appendix A
Using the ROM Monitor
Release
12.1(5)EC
12.2(4)BC1
Usage Guidelines
The boot command allows a network administrator to boot the router from the ROM monitor
(ROMMON) prompt. The router can enter ROMMON for the following reasons:
•
•
•
The boot command allows the administrator to continue the boot process or to load a new software
image.
To upgrade the router to a new Cisco IOS software image, you can use either the boot command in
Note
ROMMON mode or the boot system commands in global configuration mode.
Boot Changes in Cisco IOS Release 12.2
Cisco IOS Release 12.2 changed the behavior of the ROM monitor (ROMMON) during the bootup
sequence. Previously, users could issue the break signal during the bootup sequence to break into
ROMMON, and then immediately boot a new Cisco IOS image using the boot command.
This behavior is no longer allowed when the router is using a boot image that is based on Cisco IOS
Release 12.2, because interrupting the boot process could leave the hardware and software registers in
an unknown state. Instead, use the following procedure when using a router with a Cisco IOS Release
12.2 boot image:
At the router's console prompt, send a BREAK signal to interrupt the boot process and enter ROMMON.
Step 1
Set the configure register to boot into ROMMON by giving the confreg 0x0 command.
Step 2
Use the reset command to reset the NPE and to boot into ROMMON. This ensures a clean boot into
Step 3
ROMMON, with all registers set to a known state.
Set the configure register to boot an IOS image by giving the confreg 0x2102 command.
Step 4
Use the boot command to boot the desired Cisco IOS image.
Step 5
Examples
The following example shows how to boot the router using the first file in the default device:
rommon 1 > boot
Self decompressing the image :
#######################################################################################
[OK]
OL-1581-07
Modification
Support was added for Cisco uBR7100 series routers.
Support was added for the Cisco uBR10012 router. Changes were also made
to the boot procedure after breaking into ROMMON to ensure that all
hardware and software registers are in a known state before loading the new
image.
The administrator interrupted the boot sequence or Cisco IOS software by pressing the BREAK
signal.
The router's configuration register is set to boot into ROMMON (0x00).
The router entered ROMMON because of a software exception or error.
Cisco Broadband Cable Command Reference Guide
boot
A-9
Advertisement
Table of Contents
