3-21
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 3 Configuring the Router for the First Time
Modifying the Supervisor Engine Startup Configuration
The ROM monitor has these features:
• Power-on confidence test
• Hardware initialization
• Boot capability (manual boot and autoboot)
• Debug utility and crash analysis
• Monitor call interface (EMT calls—the ROM monitor provides information and some functionality
to the running software images through EMT calls)
• File system (the ROM monitor knows the simple file system and supports the newly developed file
system through the dynamic linked file system library [MONLIB])
• Exception handling
Configuring the Software Configuration Register
The router uses a 16-bit software configuration register, which allows you to set specific system
parameters. Settings for the software configuration register are written into NVRAM.
Following are some reasons for changing the software configuration register settings:
• To select a boot source and default boot filename.
• To enable or disable the Break function.
• To control broadcast addresses.
• To set the console terminal baud rate.
• To load operating software from flash memory.
• To recover a lost password.
• To allow you to manually boot the system using the boot command at the bootstrap program prompt.
• To force an automatic boot from the system bootstrap software (boot image) or from a default system
image in onboard flash memory, and read any boot system commands that are stored in the
configuration file in NVRAM.
Table 3-2 lists the meaning of each of the software configuration memory bits, and Table 3-3 defines the
boot field.
Caution The recommended configuration register setting is 0x2102. If you configure a setting that leaves break
enabled and you send a break sequence over a console connection, the router drops into ROMMON.
Table 3-2 Software Configuration Register Bit Meaning
Bit Number
1
Hexadecimal Meaning
00 to 03 0x0000 to 0x000F Boot field (see Table 3-3)
06 0x0040 Causes system software to ignore NVRAM contents
07 0x0080 OEM
2
bit enabled
08 0x0100 Break disabled
09 0x0200 Use secondary bootstrap
10 0x0400 Internet Protocol (IP) broadcast with all zeros
To Next Page
Loading...
Need help?
General
