Installation guide

D-4 Cisco 4000 Series Installation Guide
Virtual Configuration Register Settings
Configuring the Boot Field
The lowest four bits of the processor configuration register (bits 3, 2, 1, and 0) form the boot
field. (See Table D-2.)
Table D-2 Explanation of Boot Field (Configuration Register Bits 00–03)
The boot field specifies a number in binary. If you set the boot field value to 0, you must
have console port access to boot the operating system manually. Boot the operating system
manually by entering the b command at the bootstrap prompt as follows:
> b [tftp] flash filename
Definitions of the various command options follow:
b—Boots the default system software from ROM
b flash—Boots the first file in Flash memory
b filename [host]—Boots over the network using TFTP
b flash [filename]—Boots the file (filename) from Flash memory
For more information about the b [tftp] flash filename command, see the appropriate Cisco
IOS software publications.
1. Values of the boot field are 2–15 in the form cisco<n>-processor_name, where 2 < n < 15.
Boot Field Meaning
00 Stays at the system bootstrap prompt (ROM monitor) on a reload or
power cycle
01 Boots the boot helper image as a system image
02-F Specifies a default netboot filename
Enables default booting from system Flash memory
Enables boot system commands that override the default netboot
filename
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