User Guide

OmniAccess SafeGuard OS Administration Guide
117
Chapter 3: Working with Configuration Files and Upgrading Images
Upgrading the Boot Image
SafeGuard devices use a boot sequence to bring up the device and load application
software, such as SafeGuard OS into memory. There are two methods of performing this
boot sequence:
■ Simple – A single piece of code that performs both the bootstrap and boot loader
function.
This type of boot loader was introduced in SafeGuard OS release 1.0 and
continues to be supported. The simple boot loader provides backward
compatibility to early releases and allow SafeGuard OS users to use Release 3.0
without upgrading the boot loader. The simple boot loader stores the image into a
raw image partition.
■ Dual-stage – Two distinct pieces of code that separate the bootstrap and boot
loader functions.
This type of boot loader was introduced in SafeGuard OS release 3.0 and provides
improved reliability over the simple boot loader. The dual-stage boot loader
stores the image into a set of components that are industry-standard.
For information on migrating a simple boot loader system to a dual-stage boot
loader, see Migrating a Simple Boot Loader to a Dual-Stage Boot Loader on page 119.
To update the Boot Loader:
1 Download the new boot loader from Alcatel-Lucent to an external TFTP server.
2 Copy the boot loader to either the primary or secondary flash location.
3 Specify whether to boot using the primary or secondary boot loader.
4 Validate the configuration using the show version command.
See the following sections for more details:
■ Dual-Stage Boot Loader Upgrades
■ Simple Boot Loader Upgrades
Dual-Stage Boot Loader Upgrades
The dual-stage boot loader is comprised of two components: the bootstrap and a primary
and secondary boot loader. The bootstrap runs when the system is reset and is
responsible for locating, selecting, validating and running the boot loader. The boot
loader is responsible for loading and running application software, such as SafeGuard
OS.