Cisco Systems Accessing and Using GRUB Mode: Configuration Register on Cisco CSR

Chapter 11 Accessing and Using GRUB Mode

Using the GRUB Menu

The following shows an example of entering GRUB mode.

Router(config)# config-register 0x0000

GNU GRUB version	0.97 (638K lower / 3143616K upper memory)
[ Minimal BASH-like line		editing is supported.		For the first word, TAB
lists possible	command	completions.	Anywhere	else TAB lists the possible
completions of	a device/filename.		ESC at any	time exits to menu. ]
grub> help
[ Minimal BASH-like line		editing is supported.		For the first word, TAB
lists possible	command	completions.	Anywhere	else TAB lists the possible
completions of	a device/filename.		ESC at any	time exits to menu. ]
confreg [VALUE]			help [--all] [PATTERN ...]

grub>

If you enter a question mark at the grub> prompt, the system shows you the two options available, for either viewing the system help or for entering the confreg command.

Using the GRUB Menu

The GRUB menu is used to display the software images loaded on the router, and to select which image to boot from. To access the GRUB menu, enter ESC at the GRUB prompt. The following shows the GRUB menu display.

GNU GRUB version 0.97 (638K lower / 3143616K upper memory)
+-------------------------------------------------------------------------	+
CSR1000v - csr1000v-universalk9.03.10.00.S.153-3.S-ext.SPA.bin
CSR1000v - packages.conf
CSR1000v - GOLDEN IMAGE
+-------------------------------------------------------------------------	+
Use the ^ and v keys to select which entry is highlighted.
Press enter to boot the selected OS, or 'c' for a command-line.

Select the image to boot the router from using the up and down arrow key. To return to the GRUB prompt, enter the letter c.

Modifying the Configuration Register (confreg)

This section describes how to modify the configuration register by using the confreg GRUB command. This command is similar to the confreg ROMMON command on other Cisco hardware routers. Because the Cisco CSR 1000V does not include a ROMMON mode, the similar functionality is handled in the GRUB command mode.

You can also modify the configuration register setting from the Cisco IOS CLI by using the config-registercommand in global configuration mode.

	Cisco CSR 1000V Series Cloud Services Router Software Configuration Guide
OL-27477-07		11-3