ROM Monitor Overview
The ROMMON is the bootloader that initializes the hardware when the platform is powered on or reset. From
the ROMMON prompt, a Cisco IOS XE image can be manually booted. There is also an autoboot option to
boot a specified IOS XE image for every power-on or reset. When new features or significant defects are
resolved, a newer ROMMON release is available on CCO. To determine the current ROMMON version and
the location of the latest ROMMON release, these details are available in the following sections:
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ROM Monitor Overview
The ROM Monitor software is also known as ROMMON, boot software, boot image, or boot helper. Although
it is distributed with routers that use the Cisco IOS XE software, the ROMMON is a separate program from
the Cisco IOS XE software. During normal startup, ROMMON initializes the router, and then, the control
passes to the Cisco IOS XE software.
When you connect a terminal to the router that is in ROMMON mode, the ROMMON command-line interface
(CLI) prompt is displayed.
Access the ROMMON mode to perform these tasks:
• Specify config-register value to use for the next boot up
• Boot a valid IOS XE image
• Bypass NVRAM settings and config-register value for password recovery
Note
After the Cisco IOS XE software boots up, ROMMON is no longer in use.
Environmental Variables and the Configuration Register
Two primary connections exist between ROMMON and the Cisco IOS XE software: the ROMMON
environment variables and the configuration register.
ROM Monitor Overview, on page 53
Hardware Installation Guide for the Cisco 1000 Series Integrated Services Router
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