AIX BOOTING OVERVIEW

Booting involves the following steps:

_ The initial step in booting a system is the Power On Self Test (POST)hardware is checked then locate ROS

System Read Only Storage (ROS) is specific to each system type. It isnecessary for AIX 5L Version 5.3 to boot, but it does not build the datastructures required for booting. It will locate and load bootstrap code

Software ROS (also named bootstrap) forms an IPL control block, which iscompatible with AIX 5L Version 5.3, that takes control and builds AIX 5Lspecific boot information. A special file system located in memory and namedthe RAMFS file system is created. Software ROS then locates, loads, andturns control over to the AIX 5L boot logical volume (BLV)

A complete list of files that are part of the BLV can be obtained from the/usr/lib/boot directory. The most important components are the following:– The AIX 5L kernel– Boot commands called during the boot process, such as bootinfo andcfgmgr– A reduced version of the ODM. Many devices need to be configuredbefore hd4 is made available, so their corresponding methods have to bestored in the BLV. These devices are marked as base in PdDv.
and then

– The rc.boot script
Next booting involves three phases